CHAPTER VI 
    
  PATHOLOGICAL ACTION OF WAR GASES 
 GENERAL CONSIDERATIONS
  
  The  purpose of this chapter is to describe the anatomical lesions caused by  the poisonous  gases as they were actually observed and to present the detailed  records of 107 autopsy  protocols. The general description of the pathology is based chiefly  upon these protocols,  although advantage has been taken of experimental data to supplement  the description of the  skin lesions caused by mustard gas and to consider the possible effect  of this agent upon the  blood and blood-forming tissues. 
  
  Without  questioning the fundamental importance of the work done upon animals in  establishing the general mode of action of the different gases, it is  advisable to point out again  the difficulties in applying the knowledge thus gained to the human  material. 
  
  To  begin with, the experimental worker knew the gas that was being used,  its  concentration, at least approximately, the duration of exposure, and  the manner of application,  whether by contact or inhalation. The pathologist in the field had to  rely upon uncertain  evidence in regard to the nature of the gas; in many cases no  information of any sort was  obtainable. There was always the possibility, too, that the subject had  been exposed to more  than one kind of gas. As to the concentration and length of exposure,  it was only in exceptional cases that even a crude and approximate  estimate could be hazarded from the history of the  case, as, for instance, where a shell burst at the door of a dugout,  and it might be inferred that  the inmate had been subjected to a very high concentration for a brief  period. 
  
  There  were other complications which made the interpretation of the cases  very difficult.  Frequently the soldier was severely injured by the very gas shell which  poisoned him, or he may  have been gassed as he was lying wounded by another projectile. In  either event, the traumatic  injuries complicated the picture. For example, it was not possible to  distinguish between the  terminal pneumonia which is always present in patients dying from  infected wounds and the  secondary pneumonia consequent upon the gassing. 
  
  The  most difficult problem of all for the pathologist was to distinguish  between the direct  effect of the gas and the lesions caused by the secondary or  supervening infection of the  respiratory tract. Many of the gas casualties occurred during the  months of October and  November, when the pandemic of influenza was at its height amongst our  troops.1 There will be  pointed out in detail, later, the extraordinary resemblance between the  respiratory lesions in this  disease and those caused by certain of the irritant gases, notably  mustard gas a resemblance  which extends to the finest histological detail and which is of  considerable interest. Here will be  indicated the possible interpretations which often arose in such a  case. Were the lesions due to  the gas alone? Had an influenza infection followed upon the injury  caused by the gas? Was it  certain
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  at all that the patient  had initial gas lesions of the respiratory tract, and could he not  simply have  acquired an influenza pneumonia while he was in the hospital being  treated for skin burns? The  last possibility is indicated in some of our cases in which the  respiratory complications  developed long after the gassing, but is equally possible in some of  the more acute cases in  which death ensued. 
  
  The  experimental work upon animals seemed to establish a clear-cut  distinction between  such gases as have a vesicant or irritant effect upon the skin and  upper respiratory passages, and  gases of the edema-producing or suffocant type, such as phosgene and  diphosgene, whose action  is manifest only upon the parenchyma of the lung and which are without  obvious effect upon the  upper respiratory epithelium. In the majority of the human cases  sufficient data are at hand to  permit at least of this general differentiation in regard to the type  of gas concerned. In individual  cases, however, the matter is not so simple. Extensive pulmonary edema,  whether as a result of  the gas itself or of the succeeding pneumonia (particularly in the  influenzal cases), or as a  terminal event associated with the failing circulation, was of common  occurrence. In the absence  of precise clinical data, and of characteristic changes in the skin,  eyes, and upper respiratory  tract, the diagnosis might remain uncertain. It was particularly  difficult to decide in such cases  whether the subject might not have been exposed to a suffocant gas in  addition to mustard gas. 
  
  PATHOLOGICAL  CHANGES PRODUCED BY GASES OF THE SUFFOCANT TYPE 
  
  In  the series of 107 completely studied cases only 4 may with probability  be ascribed to  poisoning with this type of gas (Cases 1, 2, 3, 4). Death occurred in  all of these cases in 3 days  or less after gassing. In addition 2 other cases are ascribed to  phosgene in the records, but in  these the evidence in support of the diagnosis seems inconclusive  (Cases 78, 104). The first of  these (Case 78) died 14 days, the other (Case 104) 72 days, after the  alleged exposure to phosgene. The difficulties in interpreting these  cases will be evident on reference to the detailed  protocols and need not be discussed here. 
  
  This  material is inadequate for a full consideration of the pathology and  especially for a  study of the late or residual lesions which, on experimental and  clinical grounds, may  reasonably be expected to follow the inhalation of gases of the  suffocant type. The discussion,  therefore, is limited to a brief description of a typical acute case.  Through the courtesy of the  French G. A. C. the writer of this chapter had the opportunity to  witness several autopsies upon  French soldiers and to study the large collection of histological  preparations in the laboratory of  Professor Mayer at the Collége de France, and the following account is  based in part upon these  experiences, in addition to the records of the series appended and the  references in the literature. Reference is made, also, to the  observations of Wilder on his series of 50 necropsies of phosgene  cases, in which he states:2 
  
  All of these patients had passed through the  initial suffocative stage of the intoxication and had died one  hour or several hours later. Cyanosis was conspicuous in all. In some  cases the skin was an ashy gray, in others it  was distinctly violaceous. In all cases the blood in the veins was of a  deep chocolate color and very thick. The  mouth and nose were usually filled and covered with an accumulation of  frothy serous fluid. The lungs were greatly  distended and very heavy; they completely filled the thoracic cavity  and showed definite
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  imprints of the ribs. The pleural cavities in  bodies examined immediately after death contained from 100 c.c. to  1,000 c.c. of a thin serous or serosanguineous exudate. The surfaces  of the lungs were mottled with areas of  subpleural emphysema. Cut surfaces of the lungs were extremely wet and  bloody from edema and passive  hyperemia. The trachea and larger bronchi were filled with foamy serous  or serosanguineouis fluid, and pressure on  the lungs caused this to flow abundantly. The larynx, trachea, and  bronchi were moderately hyperemic but presented  no edema, erosion, or ecchymosis. 
  
  In those cases in which death was delayed for  two or three days the edema was less homogeneous,  hyperemia was more extensive, particularly at the bases of the lungs,  and zones of emphysema occurred at the apices  and at the anterior margins. There was also some atelectasis, and if  secondary infection had occurred nodules of  pulmonic consolidation were in evidence.  
  
  Histologically  the edematous material seemed to consist of liquid and the debris of  epithelial cells.  Leucocytes and erythrocytes occurred in late cases only. The cells of  the alveolar walls and those of the terminal  bronchi appeared swollen and indistinctly outlined, their nuclei  staining poorly. Many alveolar capillaries appeared  thrombosed and other capillaries were engorged. Still others appeared  to be collapsed.
  
  GROSS LESIONS 
  
  There  was a dusky, livid hue to the lips, ears, finger tips, and dependent  portions of the  body. Thin, blood-stained fluid flowed from the mouth and nostrils, or  a mushroom of foam  (champignon d' écume) projected from the lips. The opened thorax  showed the lungs bulky,  meeting in the median line, with very little tendency to collapse when  the air was admitted to the  chest. They completely filled the pleural cavities, and often showed  the imprint of the ribs. The  pleural cavities almost always contained several hundred cubic  centimeters of blood-tinged  serous fluid. The visceral pleura was under great. tension, moist, and  dotted with petechial  hemorrhages or larger reddish splotches. The color was strikingly  variegated, pale pink areas of  emphysema alternating with dark red firmer patches or even lobes of  atelectasis and hemorrhagic edema. The interlobular septa were wide and  translucent from edema. The lung weight  was greatly increased, often to 900 or 1,000 grams or even more. It  offered a tense, doughy,  cushion-like resistance, with a strong tendency to pit on pressure. The  lobules were large and  clearly defined by the edematous interlobular septa. The trachea and  bronchial tree were  completely or partially filled with pink fluid and foam and the smaller  tubes appeared distended.  The mucosa was pink or darker red, velvety, and smooth, and there was  no necrosis, ulceration,  or membrane formation. The sectioned surface of the parenchyma poured  forth fluid and foam in  great abundance. The alternation of paler, glistening areas, which  under the loop were seen to be  composed of distended vesicles, with the dark red collapsed regions,  inundated with bloody  edema, was very characteristic. Some of the cases showed disruptive  emphysema beneath the  visceral pleura, the air escaping to the subcutaneous tissue about the  neck and shoulders. 
  
  The  blood was thick and very dark in color, but its coagulability was  apparently  unchanged. Thromboses have been described in the vessels of the lung  and elsewhere but were  not present in any of the cases of the series. The right chambers of  the heart were usually greatly  dilated and full of soft very dark cruor. Petechial hemorrhages were  seen in the epicardium, in  the sheaths of the great vessels, and in the gastrointestinal mucosa.  The remaining organs, apart  from very intense venous congestion, showed nothing abnormal.
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   No opportunity was presented for study of the central nervous system.  Ricker showed that  petechial hemorrhages were found in experimentally gassed animals.3
  
  MICROSCOPIC LESIONS 
  
  In  the early cases the edematous fluid in the alveoli appeared in the  sections as a uniform  pink staining material or as a granular or shreddy coagulum. (Fig. 2.)  There was little or no  stainable fibrin. The capillaries were congested and protruded in a  tortuous manner into the  lumen of the air spaces. 
  
  FIG. 2 - Case 2. Lung.    Poisoning    with phosgene and blue cross gas. Intense alveolar edema, dilatation of      atria, stasis of leucocytes in capillaries. Epithelium of        small bronchi        is intact
  
  The  preparations studied showed no clear evidence of thrombus formation,  due to  agglutination of red blood cells, to ante-mortem fibrin deposition or  to the agglomeration of  platelets in the pulmonary capillaries. Wilder,2 however,  refers to the occurrence of thrombi, and  the experimental findings of Dunn 4 upon the impermeability  of the pulmonary capillaries to  injection of saline and carmine gelatine, and the observations of Meek  and Eyster5 upon the  agglutination of red corpuscles in vitro when phosgene is bubbled  through a suspension, make it  seem possible that the obstruction to the pill-
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  monary circulation was  not due merely to stasis but to an actual clumping of the cells under  the  direct influence of gas. In addition to the intense edema and  congestion there was diapedesis of  red blood cells, and, in some areas, more extensive alveolar  hemorrhage. The alveolar epithelium  was exfoliated and in many of the air spaces the capillaries appeared  to lie exposed. There was  usually an abnormal number of leucocytes in the blood vessels, a few of  which emigrated into  the alveoli and septal spaces. 
  
  Their  nuclei were caryorrhectic. The epithelium of the small bronchi might be  lifted up  by the underlying edema and partly exfoliated. The peri- bronchial,  perivascular, and subpleural  lymphatics were distended, usually with a granular or partly fibrinous  coagulum. In view of the  statement and the currently accepted belief, based upon animal  experiment, that the epithelium  of the upper respiratory passages is uninjured by phosgene and  diphosgene, it was rather  surprising to find that in three cases of the series the tracheal  epithelium 
  
  FIG.    3.-    Case 2. Large bronchus. The    epithelium is in part lost, in part altered, the      superficial cells      being non-ciliated, and showing hyaline degeneration. There is marked      congestion of the capillaries of the submucosa 
  
  showed a definite  lesion. In two of these cases the superficial cells were hyalinized,  the ciliated  border was destroyed, and there were signs of nuclear degeneration.  (Fig.3.) Ricker has reported  similar lesions of the bronchial epithelium in cats exposed to high  concentrations of phosgene in  the gassing chamber.3 In the third case there were in  addition definite erosions, with local  inflammatory reaction. Whether these lesions were due to the phosgene  or diphosgene alone or,  as seems more probable, to the admixture of more irritant gases, such  as chloropicrin or  diphenylchlorarsine. or whether they were the result of the early  bacterial invasion, can not be  decided from the study of the very limited material. In one of the  cases (Case 3) there had  already occurred, after 24 hours, a very massive invasion of  streptococci in both trachea and  lungs. 
  
  In  the other viscera lesions were not found which could with any degree of  probability  be attributed to the gassing. The intense venous congestion found in  the gross was evident also,  of course, in the sections. Parenchymatous
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  changes in liver and  kidney may he ascribed to the concurrent infection rather than to a  direct  toxic action of the gas upon these viscera. There has been general  agreement, indeed, that  absorption of the gas (phosgene) is unlikely, in view of its rapid  decomposition in the presence  of water. 
  
  PATHOLOGICAL  CHANGES PRODUCED BY GASES OF THE VESICANT TYPE  (DICHLORETHYSULPHIDE) 
  
  CUTANEOUS LESIONS 
  
  The  pathology of the skin lesions caused by dichlorethysulphide was very  throughly  studied by Warthin and Weller in this country and by Mayer at the  central laboratory of the  French medicolegal service at the College de France, Paris. The  studies recorded here on the  human cases coming to autopsy have been supplemented by the examination  of pieces of skin  excised at the varying intervals after the application of mustard gas  in alcoholic solution of  known strength under standard conditions. 
  
  The  gross changes which followed he application of this substance may be  summarized  as erythema, followed by vesication and a variable degree of  pigmentation. The vesicles were  usually superficial; only rarely was the superficial portion of the  corium involved. The  customary sites for the burns were the face, especially the scalp, the  eyelids, nose and lips, neck,  axillae, elbows and knees (from lying or kneeling on contaminated  ground), the under surface  of the penis and the contiguous anterior aspect of the scrotum, the  inner surface of the thigh, the  buttocks, and the hands and feet. (Pls. II, VII, VIII.)  
  
  It  is now a familiar fact that after exposure there was a definite latent  period which varied  from a half hour to six or eight hours or even longer. It was not  uncommon for small sudaminal-like vesicles to appear in crops at  intervals of days after exposure. In some cases, presumably  those exposed to low concentration of the vapor, there was produced a  very diffuse, almost  scarlatina form erythema, changing in color from a somewhat dusky pink,  through purple, to  brownish. In other cases the vesicles were surrounded by an  erythematous zone, which later  became brownish. The duration of the pigmentation was not definitely  known and probably  varied in different indivituals. Pigment flecks at the site of a small  experimental burn were  apparent after a year. The contents of the vesicles were usually clear,  although the fluid might  contain a few filmy fibrin clots. If infection occurred the fluid might  become purulent, but  ordinarily relatively few leucocytes were found on examination of the  fresh fluid. It was  frequently reported that a burn over the sacrum had developed into  decubital ulcers. 
  
  Since  deaths usually occurred from the fifth day to the end of the third week  after  exposure, the pathologist was apt to see only raw surfaces, blebs,  ulcers, scars, or pigmentation,.  Rather than erythematous lesions. These were also more apt to be in  locations subjected to long  friction during travel to the hospitals and thus, to a certain extent,  the regional distribution of the  burns, when tabulated from autopsy reports, differed from that of the  lighter burns sustained by  those who recovered. 
  
  The  earlier lesion examined histologically was excised 3 hours and 25  minutes after the  application of a 10 percent solution of dichlorethysulphide
PLATE IIMUSTARD GAS BURNS OF EXTERNAL GENITALS, WITH VESICULATION AND PIGMENTATION
    PLATE III. EXPERIMENTAL MUSTARD      GAS BURNS      (NEGRO), 6 ½ HOURS. EARLY VESICLE      FORMATION. ABSENCE OF INFLAMMATORY REACTION. 
        Note change in staining of necrotic epidermis        and vascular degeneration of nuclei at margin of vesicle.
PLATE VII. MUSTARDS GAS BURN (CONTACT) OF NECK
PLATE VIII. MUSTARD GAS BURNS OF BODY
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  in absolute alcohol,  applied for 5 minutes over an area of 1 mm. in diameter in the skin of  the  back; at the time of excision there was a slightly elevated area of  erythema about 3 mm. in  diameter. 
  
  The  only change noted in the epidermis was a slight thinning with a  flattening out of the  papillary processes; over the summit of the lesion thev were completely  obliterated. Under the  high power a few individual cells showed a vacuolated cytoplasm with  displacement of the  nucleus to the periphery of the cell. There was slight edema of the  corium; the sweat glands, hair  follicles, and sebaceous glands showed no recognizable injury; the  blood vessels, especially the  superficial capillaries, were dilated and filled with red cells and a  few were surrounded by a  loose mantle of lymphoid cells; the lymphatic vessels were distended,  containing a fine granular  coagulum; the deeper portion of the corium and the subcutaneous tissue  showed no injury. 
  
  Another  lesion was examined after 45 hours, having been produced at the same  time, in  the same individual; the lesion consisted of a small elevated vesicle  filled with clear fluid and  surrounded by an area of erythema 4 to 5 mm. in width. 
  
  The  overlying superficial horny layer was still intact, but the remainder  of the epithelium  covering the vesicle was entirely necrotic. The contents of the vesicle  consisted of interlacing  fibrin strands inclosing a homogeneous coagulum loosely infiltrated  with polynuclear  leucocytes. At the margin of the vesicle the epithelial cells were  dissociated for a short distance  but rapidly became normal. No mitoses were found and there was no  indication of increased  proliferative activity. The base of the vesicle was formed by edematous  corium which, in its  most superficial portion, was devoid of connective tissue nuclei and  was loosely infiltrated with  round cells and polynuclear leucocytes. These were most densely  aggregated about the blood  vessels. The deeper connective tissue showed no edema or inflammatory  reaction. 
  
  The  perivascular infiltration extended for a considerable distance beyond  the area of the  vesicle; the sweat glands and hair follicles in the vicinity of the  lesion showed no significant  changes. 
  
  Although  it would appear from a study of this experimental lesion that the  vesicle was  formed between the epidermis and the superficial corium, a study of  numerous other accidental  lesions showed that this was by no means always the case; the vesicle  may be formed within the  epidermis itself by a dissociation of the epithelial cells with the  accumulation of fluid between  them and their subsequent necrosis. In this way a cleft may be formed,  the epidermis and some  of the basal cells remaining visible. (Fig. 4.) 
  
  Not  only might fluid accumulate between the cells, forcing them apart, hut  the cells  themselves might undergo hydropic changes, so that the cytoplasm would  contain a single large  vacuole which pushed the nucleus in crescentic form to the periphery of  the cell. This type of  hydropic degeneration was frequently seen at all stages, especially  amongst the less severely  injured cells at the periphery of the lesion. 
  
  In  other cases individual cells, or the entire epidermis, would undergo a  hyaline necrosis,  the nucleus becoming shrunken and pycnotic and the cytoplasm taking on  a dense refractile  appearance and staining deeply with eosin. This mummified or hyalinized  epidermis,  constituting often the cap of the vesicle,
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  might persist for a long  time, showing in a shadowy way the outline of the individual epithelial  cells. It might persist until a new growth of epithelium proceeding  from the margin of the vesicle  had completely undermined it and recovered the base of the vesicle.  This was one of the  common methods by which regeneration took place. (Fig. 5.) There was no  doubt that the  sheaths of the hair follicles also played an important part in  reinvesting the base of the vesicle or  ulcer, although this was even more striking in the lesions  experimentally produced in horses
  
  FIG 4.- Case 8. Mustard-gas burn of skin    of 2    days' duration. Necrosis of epidermis, with beginning of    intra-epidermal vesicle formation
  
  The  opportunity was presented to examine histologically experimental  lesions produced  in the way indicated above in negroes. Although it has been  demonstrated by the studies of  Marshall, Lynch, and Smith, cited below (see also Chap. XII), that the  negro is relatively  insusceptible to dichlorethyl-sulphide, the lesion produced by a 10  percent alcoholic solution  differed in no respect from the lesions in white individuals. One of  the preparations excised  after six hours showed very clearly the early edema in the papillary  layer of the corium which  preceded vesiculation. The tissue was very loose and foamy, and  occasionally the entire  epidermis was elevated by a granular
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  coagulum. The same type  of degeneration of the cytoplasm was found in the connective tissue  and endothelial nuclei. There was hyperemia and a moderate inflammatory  reaction in which  polynuclear leucocytes played the leadingpart. (PWs. III, IV.) 
  
  Many  of the preparations obtained from autopsy cases showed definite  evidence of  infection, with the typical inflammatory response. Since these may be  regarded as incidental  lesions and are in nowise distinctive they need not be considered in  detail.
  
  FIG. 6.- Case 18. Mustard-gas burn of    5-6    days' duration. Section through vesicle. Overlying epithelium is    necrotic.    The contents of the vesicle consist of homogeneous, slightly fibrinous    coagulum with moderate numbers of    leucocytes. The underlying corium is edematous  
  The  pigmentation which was so striking a feature of the later stages was  due to an  increased production of melanin pigment by the cells of the rete  mucosum and was not to be  attributed to the deposition of blood pigment following capillary  hemorrhages. The pigment  production was often irregular, individual cells being loaded with  coarse clumps, while adjacent  cells might be wholly pigment free. Moreover, pigment-containing cells  could be present in abnormal situations-in the stratum granulosum, for  example, or even amongst the cells of the  keratin layer. Usually, numerous chlromatophores were seen in the  capillary layer of the corium.  (Pl. V.)
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  Where  the burn had been a severe one, and the subepithelial tissue had been  involved,  definite fibroblastic growth was found in the later stages., The  leucocytes which, in the early  stages, were chiefly polymorphonuclear, and which tended to become  fragmented as they  approached the surface, gave way to lymphoid cells; but at no stage of  the process was the  cellular reaction, in uninfected cases, a very intense one. 
  
  The  vascular lesions throughout appeared to be of minor importance.  Thrombosis was  exceptional, being found only in very severe burns in which there was a  direct necrosis of the  corium. These findings, therefore, are not
  
  FIG. 7.- Case 18. Another section,    showing    condition similar to that seen in Fig. 6
  
  in accord with the view  of other observers, who hold that the injury to the blood vessels is an  important factor in delaying the repair. The persistence of the injury  and the retarded healing  appeared to be due, rather, to the continued action of the  dichlorethylsulphide. 
  
  To  summarize briefly the lesions produced in the skin: There was caused a  hydropic  degeneration, or a hyaline necrosis of epidermal cells, often with the  formation of vesicles within  the epidermis. There was produced, also, edema of the corium beginning  in the loose tissue of  the papillae and leading to the separation of the epidermis from the  underlying connective tissue  and the formation of the vesicle. (Figs. 6 and 7.) There might be
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  in severe burns a direct  necrosis of the superficial portion of the corium. There was an initial  hyperemia and a very moderate acute inflammatory reaction in which  polynuclears were the  predominant element in the early stages. The leucocytes became pycnotic  and fragmented as  they approached the surface. A severe injury to the small cutaneous  vessels was exceptional and  thrombi were rarely found. 
  
  Regeneration  took place by a growth of new epithelium from the margin of the  vesicle, as  well as from the sheaths of the hair follicles. If the dead epidermis  was not artificially removed,  it might remain as a protective covering until healing was completed. 
  
  There  was an active growth of new connective tissue in the superficial layers  of the  corium where this had been injured. The hyperpigmentation was due to  increased melanin  production by the cells of the stratum mucosum. It was frequently  irregular and atypical.
  
  EYE LESIONS
  
  No  material was available for the study of the histopathology of eye  lesions in human  cases. The subject will be considered in Chapter XV of this volume and  in Section IV, "Ophthalmology, American Expeditionary Forces," of Part  II, Vol. XI. 
  
  LESIONS OF THE RESPIRATORY TRACT 
  
  It  is difficult to describe a typical picture, inasmuch as great  variations were encountered  in different cases. Appearances depended upon a number of factors--the  duration of life after  gassing, the concentration of the gas, and the duration of exposure.  Most of all did the lesions  vary with the character of the secondary infection which invariably  followed the original  chemical injury. One can not hope, therefore, to depict a graded series  of injuries followed by  repair. Indeed, the more cases that are studied the more difficult does  it become to trace out the  direct effects of the poison amidst the havoc wrought by the secondary  bacterial invaders, and  the more difficult is it to decide whether late changes in the  respiratory tract shall be considered  as the healing of the chemical injuries or of the infectious lesions. 
  
  It  is with this reservation, therefore, that the cases are described as  they were actually  recorded in the case protocols and notes, leaving to the experimental  workers the determination  of the precise part played by the poison itself and by the bacterial  infection in the production of  the lesions.
  
  UPPER RESPIRATORY TRACT 
  
  Mustard  gas in sufficient concentration produced a complete necrosis of the  epithelium  of the larynx, trachea, and bronchi. It was the rule for the smallest  bronchi to be less severely  injured, but yet there were many exceptions to this, and in some cases  the necrosis extended into  the smallest bronchi, infundibula, and, perhaps, although this was more  difficult to determine, to  the alveolar epithelium itself. The usual gross picture in the early  cases was that of a diphtheritic inflammation, with the formation of a  false membrane, which began at the epiglottis,  or even in the pharynx. and extended more or less continuously to the  small bronchi. (Figs. 8 to 11, PI. I.) The membrane often was firm and  tenacious and lined the  upper air passages,  forming a cast more or less
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  adherent, or there might be small adherent raised patches covering the  eroded and hemorrhagic  subepithelial tissue. In a few of the cases the membranous inflammation  did not involve the  trachea itself, but only the larger and medium sized bronchi. 
  
  Not  all the cases showed this intense diphtheritic necrosis; at times a  membrane was  entirely lacking, but the mucosa appeared rough and sandy and covered  with shreds of  fibrinopurulent exudate. It was always hyperemic and often dotted with  punctate or larger hemorrhages. In later cases the membrane might be  replaced by masses of  soft crumbling purulent or  bloody exudate. Careful dissection of the bronchial tree was very apt  to show that the  membranous casts which completely occluded the middle-sized bronchi as  far as the third or  fourth branches were replaced in the smallest branches by a softer  purulent exudate. Examination of the lining of the bronchus showed a  corresponding alteration from a rough  hemorrhagic, ulcerated surface to a smoother, merely hyperemic one. 
  
  In  later stages, when epithelial regeneration had occurred, the membrane  or exudate was  cleared away, and the surface was smooth, opaque, and thickened. How  this regeneration  occurred will become apparent in a study of the histological changes,  but it may be noted here  that even weeks or months after gassing, erosions, more or less  localized or diffuse, might  persist. This was the case where injury had been so deep-seated as to  involve not only the  superficial epithelium but also that of the ducts of the mucous glands,  so that no possibility of regeneration obtained.
  
  FIG. 8.- Mustard-gas poisoning. False    membrane    extending from epiglottis through entire trachea into bronchi  
  
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  In  a few of the cases the lesions of the upper respiratory tract were  gangrenous rather than  diphtheritic in character. (Pl. X.) The walls of the trachea and  bronchi showed greenish  discoloration, and the exudate had a characteristic foul odor. There  were usually associated  gangrenous areas in the lung itself. In two such cases the pathologist  recorded the presence of  extensive dental caries, indicating that, in his opinion, infection of  the air passages had occurred,  with the putrefactive bacteria from the mouth. This seemed a plausible  idea, and in one of the  cases it was supported by the finding of numerous fusiform bacilli in  the necrotic exudate. Spirilla were not demonstrated, but were  doubtless present. 
  
  The  histological lesions found in the trachea and bronchi were studied in a  severe case,  dying two days after exposure. The trachea and large bronchi presented  about the same picture.  There was at thick, fibrinous membrane with coarse laminated threads  running parallel to the  surface. In the meshes lay scattered nuclear fragments and a few better  preserved wandering  cells masses of mucus, also, sometimes showing a curious concentric  arrangement, were  incorporated in the fibrinous membrane. Adherent to the under surface  were the detached  epithelial cells, many of which were surprisingly little altered, still  conserving their cilia and  showing good nuclear stain. The membrane lay loosely upon the exposed  basement membrane,  being
  
  FIG. 9.- Diphtheritic necrosis of mucosa of    upper respiratory tract after mustard-gas inhalation  
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  attached only here and  there by bridges of fibrin. The basement membrane itself was swollen  and less sharply outlined than the normal structure. The subepithelial  tissue was edematous; in  places there was a definite fibrinous exudate between the connective  tissuebundles. There was a  moderate inflammatory infiltration with both mononuclear and  polymorphonuclear leucocytes.  As these approached the surface they appeared to undergo caryorrhexis,  and in the superficial  portion there was much nuclear debris. The nuclei of the connective  tissue cells also showed the  effects of the injury, their nuclei being, shrunken and pycnotic. The  blood vessels were  enormously distended, and there were small capillary extravasations.  The endothelium showed  no definite alteration. The mucous ducts were widely distended with  plugs of mucus. Near the surface their epithelial cells were apt to be  cast off and more or less degenerated. In the  deeper portion the cells lost their orderly alignment and tended oto  take on a squamous type.  The mucous glands themselves at this stage were in a state of  hypersecretion; only exception-
  
  FIG.10.- Diphtheritic necrosis of mucosa    of upper respiratory tract after mustard-gas inhalation 
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  ally were there clearly  defined degenerative changes in the gland cells to indicate a  penetration  of the poison. The loose cellular tissue about the perichondridum, and  even between and external  to the cartilages, might be edematous. 
  
  In  the case described the injury had been limited to the superficial  epithelium and had  noted to the death of the tissue below the membrana propria. Many of  the cases of the series,  however, showed a more deep-seated injury, involving the subepithelial  tissue to a variable  depth. (Figs.12 and 13.) The basement membrane appeared to offer an  obstacle to the  penetration of the poison, but when this was overcome the necrosis of  the connective tissue  frequently extended to the bands of smooth muscle fibers lying  superficial to the mucous glands.  The muscle fibers again seemed to offer a resistance to the further  penetration of the poisonous  substance. Only exceptionally was there a direct necrosis of the mucous  glands, and even in  those cases the destruction involved only groups of acini and not the  mucous glands in their  entirety.
  
  FIG. 11.- Diphtheritic necrosis of    mucosa of    upper respiratory tract after mustard-gas inhalation  
 103
  
  A  well-formed membrane was seen as early as 48 hours after gassing and  might persist  for many weeks. In cases where no membrane was present the surface of  the trachea was formed  by the exposed necrotic subepithelial tissue or by the smooth and wavy  contour of the basement  membrane. (Fig.14.) In the early stages shreds of epithelium were  still to be found here and  there, but these were rapidly cast off and replaced by regenerated  cells in a manner to be  described. 
  
  The  reparative processes which followed the injury above described were  most  interesting. As early as four or five days after gassing, a beginning  reinvestment of the trachea or  bronchus might have taken place. The new cells were derived from little  islands of epithelium  still adherent to the membrana propria which had escaped the initial  destruction and from the  epithelial cells which had lined the ducts of the mucous glands.  (Fig.15.) These 
  
  FIG.    12.- Mustard-gas burn. Deep-seated necrosis of      bronchial mucosa 
  
  cells divided and crept  out over the mouth of the duct covering the adljacent exposed basement  membrane, first with a single layer of flattened cells, latter with a  multilayered squamous  epithelium. These duct cells seemed to play a very important role in  elpithelial regeneration, and  it was at common finding to see the entire duct filled with at solid  nest of actively dividing cells.  In this way, provided the destruction had not been too intense, the  entire surface might he  reinvested with a metaplastic epithelium of the squamous cell type.  (Fig. 16.) Whether the  superficial cells of this layer later became replaced by cylindrical  ciliated cells can not be  definitely stated until opportunity has presented to examine further  material from late cases. In  one of the cases after 167 days, in which typical mustard gas lesions  were still present in the  bronchi, the trachea showed a multilayered but ciliated epithelium. The  majority of the late  cases, however, showed epithelium of the squamous cell type, andl it is  prolbable that. in most  cases the metaplasia was at permanent change. 
  
  Certain  of the cases showed interesting details in regard to the process of  epithelial  regeneration. Worth noting is the fact that regeneration might begin  while the memlbrane was  still present, so that it was not unusual to find a
 104 
  
  layer of flattened cells  showing many mitotic figures, often highly atypical in character,  interposed between the fibrinous exudate and the basement membrane.  Often it seemed as if the  epithelial growth had outstripped the other processes of repair, so  that the growing cells  themselves, because of being improperly nourished, degenerated.  (Fig.17.) Some of the  preparations showed the new epithelium lifted up from the membrana  propria by a granular  coagulum, as if a new vesicle had been formed. This appearance leads  one to
  
  FIG. 13.- Case 22. Mustard-gas burn, 5    days'    duration. Deep necrosis of tracheal mucosa 
  
  ask whether there may  not have been a persistence of the poison and whether this late and  secondary vesicle formation may not be comparable to the late  appearance of skin vesicles four  or five days after gassing. 
  
  One  of the preparations showed the duet epithelium growing beneath the  still preserved  basement membrane. (Fig.18.) This anomalous growth was due to the  proliferation of the duct  epithelium beneath the partially loosened membrana propria. In one of  the late cases, scattered  through the, sub-epithelial tissue, were solid nests of cells which  resembled very closely  squamous-celled carcinoma. The cells were arranged as in  epitheliomatous pearls; they
 105 
  
  were definitely  squamous, highly atypical, often multinucleated, and showed numerous  mitotic  figures. Intracellular fibrils even were to be seen between them. This  appearance was brought  about by the proliferation of the duct epithelium within the lumen.  (Fig.19.)
  
  FIG.14.- Case 21. Mustard-gas burn,    5days'    duration. Necrosis and exfoliation of trachea lepitheliuim      exposing      basement membrane. Fibrinous edema of submucosa
  
  As  regards the lesions in the submucosa, it has been stated above that in  the majority of  cases he cellular response was not very marked, and in some cases, in  the trachea at least,  practically wanting. Bacterial stains showed that the organisms rarely  penetrated below the  surface. In one of the cases, however, in which there was an extreme  edema not only of the  submucosa tissue but also) of the areolar tissue external to the  bronchus, a Gram stain showed  unrestrained growth of Gram-positive cocci throughout the edematous  area.
 106
  
  With  the beginning of repair the connective tissue cells in the submucosa  took on the  character of fibroblasts. New blood vessels were formed which were  sinusoidal in character and  which formed wide channels extending to the basement membrane, where  this was still intact.  The inflammatory cells then became predominatingly lymphoid in  character, and numerous  plasma cells and other large mononuclear elements were present. This  formation of a very vascular granulation tissue was found not only in  the trachea and large bronchi, but in the  medium-sized and smaller bronchioles, where it sometimes led to a 
  
  FIG. 15.- Case 61. Mustard-gas burn, 9    days'    duration. Epithelial regeneration of trachea, proceeding      from the      mucous ducts 
  
  pronounced thickening of  the wall, with narrowing of the lumen. As we have stated above, the  granulation tissue might or might not be reinvested by epithelium  according to whether the  initial injury involved the epithelium of the mucous ducts or not. 
  
  In  a few of the cases in which the mucous glands were injured it was  possible to study a  regeneration of these structures. The acinus was filled with a  pink-staining, more or less hyaline,  necrotic mass, embedded in which were nuclear particles. This  represented the remains of the  necrotic gland cells, and at the periphery the new secretory epithelium  was seen pushing its way between the necrotic cells and the basement  membrane of the gland.
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  LUNGS
  
  The  appearance of the lungs at autopsy presented a bewildering variety, and  it is quite  impossible to describe a composite picture which would distinguish the  lungs of mustard-gas  poisoning from those of the various types of pneumonia. Perhaps the  most distinctive cases were  the very early ones, in which the pulmonary lesions were largely  confined to the bronchi and  their immediate neighborhood. The lung was voluminous and did not  collapse readily after  removal. Occasionally the pleura was smooth, but in most cases there  were patches of early  fibrinous pleurisy. Darker sunken area of atelectasis 
  
  FIG. 16.- Case 41. Mustard-gas burn, 7    days'    duration. Metaplasia of tracheal epithelium into squamous cell type.    Numerous mitoses 
  
  associated with the occlusion of bronchi were  visible on the surface. On section the most  conspicuous features were the thickened bronchi filled with plulgs of  creamy fibrinopurulent  exudate, or in the case of the smaller bronchi a droplet of creamy pus  might exude. Each  bronchus was surrounded by a dlark reti sunken areola 2 or 3 mm. in  width. This last feature is  regardedl as particularly characteristic; the red peribronchial zone  histologically was found to be  composed of the adjacent alveoli, which were filled with red blood  cells and more or less  collapsed. Further outward from the bronchus the hemorrhage
 108 
  
  gave place to a fibrinous exudate in which  only a few desquamated alveolar cells and occasional  leucocytes were included. (Pl. IX.) This peribronchial reaction did not  appear to he due to a  direct extension of the infection within the bronchus through the  bronchial wall. It would seem  that the hemorrhage was caused by the direct action of the toxic agent  diffused through the wall  of the bronchus. The collapse may perhaps be explained by the  distension of the small bronchus  with compression of the adjacent air spaces. Frequently, at least, the  alveoli directly adjoining  the bronchus appeared flattened.
  
  FIG. 17.- Case 24. Mustard-gas burn, 5    days'    duration. Between the false membrane and the congested sub-epithelial    tissue are interposed hydropic epithelial cells of the      squamous type 
  
  Aside  from these bronchial and peribronchial lesions the lung, on section,  showed  emphysema and darker areas of partial collapse. Edema was present to a  greater or less degree in  about two-thirds of the cases. It was never so extensive as in the lung  of phosgene or other  asphyxiating gas and was often patchy in its distribution, being much  more marked in some  portions of the lobe than in others. From the autopsy records, which  naturally vary greatly in  detail and accuracy, it appears that excessive edema was noted in only  three cases occurring two  and three days after gassing, and in one case in which
 109 
  
  the period of survival was not established;  moderate general edema was present in 28 cases and  slight patchy edema in 43 cases. In 18 cases the absence of edema is  specifically reported, and in  6 cases no record was made. 
  
  As  with so many of the pulmonary lesions, it was difficult to decide  whether this edema  wits the direct result of the action of the mustard gas upon the  alveolar capillaries or whether it  was due to secondary infection, to the failing circulation, or to other  obscure factors. It is true  that even in the early cases bacteria abounded in the bronchial and  infundibular lesions. They  were not usually present, however, in the edematous areas at a distance  from the bronchi. This,  and the fact that the most intense edema was recorded
  
  FIG. 18.- Case 89. Mustard-gas burn 20    days'    duration. Trachea. The regenerating epithelium is growing      beneath      the old swollen basement membrane, which covers the exposed surface 
  
  in relatively early cases, is perhaps an  argument in favor of the direct edema- producing action  of the mustard gas. Experimental observation also supports this view.  It was possible in rabbits  by intravenous injection to produce moderate pulmonary edema  (Pappenheimer and Vance).6 Lynch, Smith, and Marshall made similar observations in dogs. 7 In cases which died late the  edema, when present, was in all probability secondary and not due to  the initial chemical injury. 
  
  The  great majority of the cases showed, in addition to the bronchial and  peribronchial  lesions, areas of focal pneumonia, sometimes small and nodular, often  large and confluent.  There was no constancy in the appear-
 110 
  
  ance of these pneumonic patches, nor could  one find sharply cut differences in the appearances  in cases dying early after gassing and in those which survived for  weeks or even months. A fresh  bacterial infection might develop at any stage after the initial  chemical injury, and it was not  uncommon to find in the same lung recent and older organizing lesions. 
  
  During  the height of the influenzal epidemic in October and November, 1918,  many of  the gas pneumonias exhibited the characteristic gross features which  had come to be associated  with the pulmonary lesions of influenza. The lungs were heavy and  voluminous and often a  dusky red, especially in the posterior portions. There were fresh  pleural hemorrhages and more  or less fine fibrinous pleurisy which became organized in the later  cases. Only twice was the  pleurisy suppurative in character; in one of these cases (Case
  
  FIG.    19.- Case 86. Mustard-gas burn,    18 days'    duration. Bronchus. Proliferation of epithelium of      ducts of mucous      glands 
  
  99), the empyema was due to the extension of  a traumatic liver abscess; in the other (Case 25),  which occurred in August, the pleurisy was not extensive, and the  resemblance of the pulmonary  lesions to those found in influenza were less striking than in many  other cases. 
  
  On  section these lungs showed, in addition to the characteristic  membranous bronchitis  and bronchiolitis and peribronchial areola, diffuse, often incomplete  areas of consolidation  associated with much hemorrhagic edema. (Fig. 20.) The greater portion  of one or several lobes  was frequently affected. In some of the later cases there are described  also opaque grayish areas  of necrosis and groups of small abscesses. Organization was not  infrequentlv recognized in the  gross by some of the more experienced pathologists and confirmed  histologically. (Fig. 21.)
 111
  
  In  describing the histological changes associated with this type of pneu-  monia attention  is called again to the extraordinary resemblance of the finer changes  to those observed in the  primary influenzal cases. These lesions can not be ascribed wholly to  the influenzal or  postinfluenzal infection, in as much as they may be reproduced in  animals by exposure to the gas  alone, and have been present also in human cases dying at times when  the epidemic was not  active.
  
  FIG. 20.-    Case 28. Mustard-gas burn, 4-5    days'    duration. Lung: Intense congestion, hemorrhagic edema,      aplastic      exudate. The lecuocytes are filled with minute Gram-negative bacillli
  
  Leaving aside the larger  bronchi, which have been described and  in which the membranous  character of the necrosis is usually more extreme than in the primary  influenzal cases, the  terminal bronchioles were found usually with their ciliated epithelium  more or less conserved.  There was an acute suppurative inflammation, which was in nowise  distinctive. The atria,  however, were often widely dilated; they might or might not themselves  contain exudate. (Fig. 22.) The wall was lined by a wavy hyaline band,  which sometimes, but not regularly, gave a  faint fibrin stain with the Gram-Weigert-safranine method. (Pl.-VI.) It  was a little difficult to be  sure of the composition of this hyaline band. It
 112 
  
  did not appear to be composed solely of the  necrotic lining epithelial cells, although these  probably took part in its formation. The continuity of the membrane  with definite bands of fibrin  in the walls of the atria or alveoli indicated that the fibrin was at  least the chief constituent.  Later, as it became more and more swollen and hyalinized, the specific  staining was less readily  obtained. In part it might have been due to the condensation of a  highly albuminous material  about the wall of the infundibulum.
  
  FIG. 21.- Case 103. Mustard-gas burn, 5    days'duration. Lung: Organizing and interstitial pneumonia
  
  The  lesions found in the alveoli were manifold. The alveolar exudate in the  vicinity of  the bronchioles and atria was apt to be fairly cellular, containing, in  addition to a variable  number of red cells, leueocytes of various types, but predominantly  polymorphonuclear. But  there were large areas in which the exudate was characteristically poor  in nucleated cells and  was rather of the nature of a hemorrhagic edema. The fluid either  contained a loose fibrin net or  appeared merely as a homogeneous or fibrinous coagulum. There would be  merely diapedesis of  red cells or more profuse hemorrhages, leading to disruption and  necrosis of the lung tissue and  distinguishable from infarcts only by the absence of thrombi within the  la roer arteries. The alveolar capillaries
 113 
  
  in these portions of the lung were  tremendously distended, bulging into the alveolar spaces. (Pl.  VI.) Sometimes it appeared as if the membrane upon which the  endothelium rests was swollen  and thickened. Fibrin thrombi were fairly often found within the  capillary lumen, and in some  cases were quite abundant. It was very common also to see coarse fibrin  threads deposited in the  septa between the capillary wall and the epithelium. Edema of the  alveolar
  
  FIG. 22.- Case 81. Mustard-gas burn, 15    days'    duration. Lung. Dilatation of atria, with hyaline necrosis 
  
  wall was often striking, and the still intact  alveolar epithelium could be elevated at times as a  continuous sheet of cells. 
  
  The  alveolar epithelium itself in the early acute cases often appeared  swollen and  vacuolated, although it was only occasionally that degenerative changes  could be recognized in  the still adherent cells. There was always more or less exfoliation,  the cast-off cells becoming  rounded, taking up red cells, pigment granules, leucocytic nuclear  fragments, losing their nuclear  staining eventually, and becoming degenerated.
 114
  
  Necrosis of the capillary wall was observed  repeatedly, with fragmentation of the  endothelial nuclei and of the leucocytes, as recently described by Le  Count in cases of primary  influenzal pneumonia, and regarded by him as highly characteristic.8 (Fig. 23.) 
  
  Just  as the bacteriological studies in influenzal pneumonia showed in the  lung a varying  flora, so the bacteriological data in the series of gas pneumonias  studied failed to throw any light  on the difference in anatomical types. Both
  
  FIG. 23.- Case 22. Mustard-gas burn, 5    days'    duration. Lung: Pneumonia, with necrosis of alveolar walls and    nuclear fragmentation 
  
  culturally and in bacterial-stained sections  a variety of forms was found. In a few cases, and  these unfortunately were uncontrolled by cultures, the sections showed  enormous numbers of  minute Gram-negative rods as the predominating organism in the alveolar  exudate. Many other  cases, grossly and histologically similar, showed only Gram-positive  cocci. So confusing were  the findings that it seemed not worth while to attempt an analysis,  particularly as no systematic study could be carried on.
 115 
  
  REPARATIVE CHANGES 
  
  The  regenerative changes in the trachea and larger bronchi have already  been described.  Although bacteria were always present, the destruction produced by the  chemical irritant was of  so gross a character that the róle of the bacteria may well be regarded  as altogether secondary,  particularly as they rarely invaded the deeper tissues. The healing  process also may be looked  upon as a repair of the chemically injured tissue. But in the  parenchyma of the lung,
  
  FIG. 24.- Case 53. Mustard-gas burn    (history    of exposure also to green and blue cross shells), 8 days' duration.    Lung, small bronchus, lined with dense granulation tissue;      thickening      of septa of adjacent alveoli, which contain      plugs of dense fibrin undergoing early organization 
  
  where the original chemical injury was lost  or overshadowed by the bacterial infection, it  became quite impossible to say whether the reparative and organizing  processes which were  present in the later cases were in response to the chemical or the  bacterial poison. But it was  these late and permanent changes, however brought about, which were of  the greatest practical  interest, and it is necessary to describe them in some detail in order  to form an approximate idea of the damage which may be expected to  ensue upon the gassing
 116
  
  The  thickening of the walls of the small bronchi was an alteration which  was quite  evident in gross sections of the lung. The section showed the bronchial  wall replaced by a  vascular granulation tissue, with lymphoid and plasma cells  predominating. Where the epithelial  lining had failed to regenerate this granulation surface lay exposed,  and it can not be doubted  that the further contraction of this tissue would lead to narrowing or  complete occlusion, with the  formation of bronchiectases distal to the stenotic area. (Fig. 24.) 
  
  Bronchial  stenosis, also might result, though apparently not so frequently as one  might  expect, from the organization of the exudate within the bron-
  
  FIG.    25.- Case 100. Death, 51 days    after    exposure to mixed vesicant and suffocant gases. Section      through dilated      bronchiole, containing a vascular organized plug 
  
  chiole. This seemed to occur more often in  the ductus alveolaris, where the organizing fibrinous  plugs extended into the contiguous alveoli. (Fig. 25.) 
  
  The  zone of atelectasis, hemorrhage, and fibrinous edema which so often  encircled the  medium-sized and smaller bronchi has been described. In this zone,  where the fibrin offered  support to the growing cells, active organization was regularly found  in progress, even when the  pneumonic process at a distance from the bronchi was in full blast. It  was in this peribronchial  zone also that there was found, as in the later stages of the primary  influenzal pneumonias, a  remarkable proliferation of the alveolar epitheliums. The new cells,  distinguished by their deeper  Staining, their cuboidal form, and often
 117 
  
  by numerous kinetic figures, not only  reinvested the cavities of the alveoli but grew over and  even into the plugs of fibrinous exudate (Fig. 26), and in some  instances formed solid,  carcinoma-like nests of cells. The alveolar septa also were thickened  by the growth of  fibroblasts, the new-formed connective tissue being continuous with the  granulation tissue about  the small bronchi, and also with the new-formed fibrous tissue which  invaded the edematous  tissue about the arteries and interlobular septa.
  
  FIG. 26.- Case 74. Mustard-gas burn, 12    days'    duiration. Lung. Proliferation of alveolar epithelium over a mass of    fibrin and agglomerated red blood corpuscles
  
  LESIONS IN OTHER ORGANS 
  
  The  study of human cases afforded little evidence that mustard gas, through  cutaneous  application or by inhalation, could be absorbed and could produce  systemic effects in other  organs. In dogs exposed to high concentrations in the chamber, the  hydrolysis product,  dihydroxyethylsulphide, has been dletected in the urine by reconverting  it into  dichlorethylsulphide and obtaining a vesicant action upon the human  skin (Lynch and Marshall)  .9 So far as is known no similar demonstration has been  made in man. 
  
  Clinically  there has been observed a group of cases with diffuse pigmentation,  marked  apathy andl asthenia, low blood pressure, and often pronounced mental  disturbances, symptoms  which it is difficult to correlate with the obvious lesions of the skin  and respiratory tract. Indeed,  in some of these
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  cases, respiratory damage may be quite  insignificant. Such cases certainly suggest a systemic  intoxication of some sort, and Satre and Gaos,10 and other  French clinicians have attributed the  symptoms to an acute adrenal insufficiency. No anatomical evidence has  been brought forward  to incriminate the adrenals, and the observations are not sufficiently  definite to justifyany far-reaching conclusions. The lassitude and  asthenia, and even the mental disturbances, in men  freshly returned from combat, are perhaps more easily explained in  other ways. 
  
  More  direct proof of the absorption of dichlorethysulphide are the changes  in the bone  marrow and in the circulating blood. Zunz, 11 Stewart, 12 and later Krumbhaar 13 have shown that  severely gassed cases, after an initial leucocytosis, may develop a  marked leucopenia. and  similar observations have been made by Muratet and Fauré &-Fremiet  in animals. Pappenheimer and Vance 6 have also shown that  intravenous injections of small doses in rabbits brought about  a profound leuceopenia. with destruction of the granulocytes in the  bone marrow, an effect  comparable in its specificity with that of benzol. This has been  confirmed by Warthin and  Weller.14 Krumbhaar and Krumbhaar have brought  confirmation of their clinical evidence by a study of the bone marrow  in human cases.15 It may be taken as proved, therefore, that  when  introduced into the body dichlorethylsulphide is a specific poison for  the hematopoietic tissue,  and there are both clinical and experimental reasons for believing that  a similar effect follows  the inhalation of massive doses.
  
  LESIONS OF TIHE ALIMENTARY TRACT
  
  Abdominal  tenderness, anorexia, nausea, vomiting, and less frequently diarrhea  were  observed clinically in a large proportion of mustard-gas cases. The  experiments of Warthin and  Weller, 12 Lynch, Smith, and Marshall, 8 Pappenheimer and Vance,6 and others, have shown  that the intravenous or subcutaneous injection of dichlorethylsulpbide  in animals may be  followed by a hemorrhagic enteritis. Norris 16 refers the  subimucous hemorrhages of the stomach and duodenum to the swallowing of  contaminated saliva, but the possibility of the  elimination of the absorbed substance or its hydrolysis products  through the alimentary tract has  not been disproved. This possibility is suggested by the experimnental  facts citedl above and on  clinical grounds by Ramon, Petit, and Carrié. 17  
  
  In  the human protocols studied the alimentary tract was not examined in  about half of the  cases; in about 25 per cent of the cases the stomach and intestines are  specifically stated to be  normal; in the remainder there are noted injection or hyperemia,  sometimes of the stomach, more  commonly of the small intestine; hemorrhages in stomach, small or large  intestines, erosions or  small ulcers, in three cases in the stomach, once in the small  intestine, once in the colon. 
  
  Too  much weight should not be placed on these fragmentary references. The  injection  may be attributable to the general visceral stasis, which is the rule  in the fatal cases.  Hemorrhagic erosions of the stomach are so frequent a finding in any  large series of autopsies  that their oceasional presence in these cases does not seem very  significant. On the other hand, a  more careful scrutiny mligtht have shown a higher incidence of  gastrointestinal lesions.
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  LESIONS OF THE LIVER
  
  No  changes were found apart from those common to all acute infections.  Patients dying early  have not shown degenerative changes which might be ascribed to a  specific effect of the mustard  gas.
  
  LESIONS OF THE CIRCULATORY ORGANS
  
  No anatomical alterations of the myocardium were  found which  might throw light on the  late circulatory disturbances (effort syndrome) noted in a certain  proportion of gassed  individuals. Dilatation of the right side of the heart is not  infrequently mentioned and may be  regarded as secondary to the pulmonary lesions. It was not always  evident at autopsy.  Suppurative pericarditis as a secondary infection with hemolytic  streptococci is recorded in one  case. Nor was there found a typical or characteristic vascular lesion  in the lung or elsewhere,  which could not be of infective origin. That the frequent occurrence of  rather marked pulmonary  edema in the severe early cases implies an alteration in the  permeability of the blood vessels may  be assumed, but the cellular changes in the endothelium are not  sufficiently definite to warrant  description. 
  
  LESIONS OF THE KIDNEYS 
  
  Apart  from incidental lesions, obviously antecedent to the gas poisoning,  these organs  showed only an intense venous and capillary congestion. In one case  only were there  hemorrhages into the capsular spaces and tubules. No alterations which  would suggest a toxic  effect upon the renal epithelium were noted. The intense congestion is  probably sufficient to  explain the diminished urinary output, albuminuria, presence of casts  and red blood cells  described by Hermann 18 as typical urinary findings during  life.
  
  LESIONS OF THE CENTRAL NERVOUS SYSTEM 
  
  Unfortunately  there were available no data upon possible finer alterations in the  central  nervous system. In very few cases was the brain examined, and in none  of these were significant  gross changes detected, nor was material for histological study  preserved. Stewart12 has  described ring hemorrhages in the brain associated with swelling and  degeneration of the  endothelium, thrombosis, and slight leucocytic emigration.
  
  LESIONS OF THE ORGANS OF INTERNAL SECRETION 
  
  No  facts of value have been deduced from the incomplete study of the  adrenal gland and  other organs of internal secretion which have been occasionally  included in the material  studied. 
  
  DETAILED  AUTOPSY PROTOCOLS OF 107 CASES, WITH MICROSCOPIC EXAMINATION OF  TISSUES
  
  The cases are arranged according to the period of  survival after  gassing. In the majority  of the cases the date of gassing is accurately stated; in some it is  inferred from the date of the  first admission to field or evacuation hospital. Frequently additional  data have been disclosed by  the study of the reports of the gas officers of the Chemical Warfare  Service, and the clinical  records on file in the Oflice of the Surgeon General. Such information  has been included
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  in the autopsy record. In a few instances,  where the date of gassing is not given, it may be  reasonably surmised from the fact that other members of the same  company, battalion, or  regiment were gassed about the same time and showed lesions similar in  character. In only two  cases was it not possible to obtain data roughly estimated from the  character of the lesions. 
  
  While  the effort has been made to present the records of the gross lesions as  nearly as  possible in the form and expressions used by the pathologist who  performed the autopsy, it has  been thought desirable to omit detailed descriptions of lesions  irrelevant to the gassing and  where necessary to alter the arrangement for the sake of uniformity.  The reports will naturally  be found to vary greatly in accuracy and completeness. Many of the  autopsies were done under  conditions where there was neither time nor facility for detailed  observation and record. It seems  hardly necessary to apologize for these defects. 
  
  CASE 1.- M. L., 64329, Pvt. Co. L, 192d Inf.  Died, October 28, 1918, 2 p. m., Evacuation Hospital No.  7. Autopsy -hours after death, by Capt. James F. Coupal, M. C. 
      Clinical    data.- Date of gassing not  recorded. October 28, men of company were exposed to shell which had  little odor, produced marked sneezing, with casualties five hours  later. Severe dyspnea. 
  Anatomical diagnosis.– Not recorded. 
      Gross findings.- (The following note upon the lesions of  the respiratory tract was made in the pathological  laboratory, experimental gas field). The pharynx, larynx, and esophagus  are normal. The trachea also shows no  gross lesions. The primary and secondary bronchi show a reddened  mucosa, covered with loose shreds of tenacious  mucus. Their mucosa is intact. Right  lung: Voluminous, weighs 735 grams. The pleura is smooth,  mottled with  darker patches which are slightly sunken. On section the lung is air  containing in all lobes. There is a very moderate  general edema, somewhat more marked in the anterior portion of the  lung. Left lung: Weight, 705  grams; somewhat  more voluminous than the right. The pleura is free from exudate. On  section there is pretty marked general edema,  with scattered patches of collapse. No pneumonic patches. The small  bronchi are normal. 
  
    Microscopic examination.- Trachea: In some places the  epithelium is definitely necrotic and replaced by a  mucopurulent exudate, the membrana propria being interrupted in some of  the eroded places. In other places the  nuclei of the epithelial cells, which are reduced to a single row, are  definitely pycrotic in comparison with the  vesicular nuclei of the uninjured cells. The vessels of the submucosa  are congested. Lung: The epithelium of the  smaller bronchi is uninjured; the lumina contain a small amount of  coagulum, desquamated cells and a few  leucocytes. Many of the alveoli contain homogeneous, pink-staining  material which is practically cell free. The septa  are thickened and edematous. There is a stasis of leucocytes in the  capillaries. No bacteria are found in sections  stained with Gram-saffranine. .myocardium: There is distinct edema  about the intermuscular vessels and of the  connective tissue between the muscle bundles. Liver, kidney, spleen,    adrenal, and pancreas show no significant  lesions.
  
  NOTE.-The  lesions suggest exposure to a mixture of the suffocant and irritant  types of  gas, possibly phosgene and arsene compounds. There was definite  necrosis of the bronchial  epithelium such as one would not expect to find after phosgene alone.  The absence of bacterial  growth and secondary pneumonic lesions may be taken as evidence of  early death in this case,  probably within 24 hours. 
  
  CASE  2.- A. D., 1429216, Pvt. Hdqrs. Co., 39th Inf. Died, October 11, 1918,  4.45 a. M., Evacuation  Hospital No. 6. Autopsy, five hours after death, by Capt. James F.  Coupal, M. C. 
  
  Clinical    data.- Gassed October 10, near Verdun, blue cross      and      green cross      shells. Clinical        diagnosis of phosgene poisoning.
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  Anatomical    diagnosis.- Edema and  congestion of lungs; emphysema;  bronchopneumonia. External  appearance.--Marked post-mortem lividity. No burns of skin. Quantities  of frothy fluid exude from mouth. 
      Gross    findings.- Pleural cavities: Very slight retraction of lungs after  removal of sternum. Each cavity  contains about 60 c. c. of straw-colored fluid. Lungs:  Voluminous and extremely mottled, dark red areas of  congestion alternating with pink areas of emphysema. On section the  left lung especially shows numerous miliary  areas, apparently connected with the finest bronchi. On examination  with a hand lens these are found to be  composed of aerated alveoli surrounded by dark red edematous and  congested lung tissue. This appearance is less pronounced in the right lung. The  parenchyma in general shows intense congestion but relatively little  edema. Neck    organs: Tonsils and lymphoid tissue at the base of the tongue  enlarged. The mucosa is smooth, velvety, much  congested, but there is no ulceration or exudate. The smaller bronchi  appear normal. Heart: Cavities of right side  extremely dilated. Remaining organs show no distinctive changes.  Gastrointestinal tract: Not recorded. 
  
  Microscopic    examination.- Trachea  and bronchi of larger caliber: Ciliated epithelium is lost. The  superficial  cells show pycnosis of their nuclei and a homogenization of the  cytoplasm. In occasional cells are found hydropic  vacuoles with crescentic compression of the nucleus. The membrana  propria is thick and swollen. The blood vessels  of the sub-mucosa are congested, but there is no hemorrhage and little  or no inflammatory reaction. (See fig. 3.) Lungs: The small bronchi show a normal epithelium which is often  desquamated or elevated in strips from the  underlying basement membrane by a collection of edematous fluid. The  infundibula are dilated; they have no  epithelial lining. The surrounding alveoli show marked changes  consisting of edema, hemorrhage, desquamation of  epithelium, and the presence of numerous pigment cells. There are  excessive numbers of polynuclears in the  capillaries, the nuclei of which, especially in the neighborhood of the  infundibula, show striking distortion and  fragmentation. Elsewhere there is patchy edema, the coagulum being  homogeneous and containing little fibrin.  Gram-positive cocci are found both in the bronchi and in the alveolar  coagulum. Liver, spleen, and adrenals: No  significant changes. 
  
  NOTE.- In  spite of the clinical history of phosgene, and the gross appearance of  the lung,  the lesions suggested the admixture of an irritant gas, possibly an  arsine compound, acting  especially upon the infundibula and the adjoining lung tissue. There  was no extensive bacterial  infection of the lung, masses of bacteria being found only in the small  bronchi. 
  
  CASE  3.- C. G., French soldier. Died, October 8, 1918, at 8 a. m., Gas  Hospital, Julve-court. Autopsy, six  hours after death, by Capt. James F. Coupal, M. C. 
  
    Clinical data.- Gassed with phosgene on October 7. Died  suddenly after sitting up, without great preceding  dyspnea. 
  Anatomical diagnosis.- Massive pulmonary edema; dilatation of  right heart; acute tracheitis.  
  External appearance.- The body  shows marked lividity. 
      Gross findings.- Pleural cavities: Each contains about 300 c. c. of  blood-stained fluid. Respiratory organs:  (Note dictated upon receipt of specimens at the pathological  laboratory, experimental gas field.) Larynx: Shows no  edema. Trachea: Is discolored dark purplish- red. Bronchi:  Contain frothy fluid and their mucosa is stained with  blood. Right lung: Extremely large and dark purplish in color;  the surface is smooth, the lobular markings being  entirely obliterated. On section the lung is dark, firm, and rubbery,  but showing no evident pneumonic consolidation;  there is most intense edema, bloody fluid dripping from the cut  section. The smaller bronchi do not contain purulent  exudate. Left lung: Differs from the right in the appearance of  the lower lobe, which, in its lower portion, is  somewhat grayish, dryer, and more granular than elsewhere, suggesting  early pneumonic consolidation.  Gastrointestinal tract and remaining abdominal viscera normal save for  congestion. Heart: Right side markedly  dilated, left ventricle in extreme contraction. 
      Microscopic examination.- Trachea: There are definite lesions in certain  areas. Where the epithelium is  entirely defective the nuclei of the underlying connective tissue cells  and lymphoid cells show marked caryorrhexis,  and there is superficial necrosis, with groups of Gram-positive cocci  in the necrotic tissue and in the blood vessels.  There is also super-
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  ficial hemorrhage. Lesser injury to the epithelium is  indicated by vacuolization of individual cells, or hyaline, pink  staining of their cytoplasm. Where the epithelium is intact and  composed of several layers, there is loss of cilia; but  efforts at repair are suggested by the presence of numerous mitoses. Lungs:  Sections of various blocks show similar  picture. The alveoli are widely distended. The alveolar capillaries are  wide and crowded with decolorized red blood  cells. In the larger vessels the red cells are better preserved. In  some of the septa it is possible to make out  extravasation of cells between the capillary and the somewhat swollen  basement membrane upon which the alveolar  cells should rest. There is slight diapedesis into the alveolar spaces.  The capillaries contain moderate numbers of  mononuclear and polymorphonuclear leucocytes, some in process of  emigration. A few alveoli contain dense  collections of pycnotic leucocytes and much granular coagulum. The  alveolar epithelium is not distinguishable.  There is no fibrin. In some sections the edema is more evident, as  shown by the abundant pink-staining coagulum. Sections stained for bacteria show  enormous numbers of Gram-positive cocci in chains, pairs, and groups.  They are  found in the connective tissue about the blood vessels, in the septa  outside the capillaries, and within the  polymorphonuclear leucocytes of the alveolar exudate. No other types of  bacteria are present. Liver, spleen, kidney,  and adrenals show no significant changes. 
  
  NOTE.- A  case of poisoning by suffocative gas, probably phosgene. There appears  to  have been complete death of alveolar epithelium, with massive invasion  of bacteria  (streptococci?) and hemolysis. The bacterial growth was probably not  postmortal, since the  autopsy was performed within six hours after death. There was very  little inflammatory reaction.
  
  CASE    4.- H. R., 76213, Pvt. Co. B,  18th Inf. Died,  August 8, 1918, Gas Hospital No. 4. Autopsy, 11 hours  after death, by Lieut. Russell W. Wilder, M. C. 
      Clinical    data.- October 7, exposed to bombardment of phosgene and  mustard-gas  shells (77.105.150 mm.).  Clinical diagnosis: Phosgene poisoning. 
  Anatomical    diagnosis.- Diffuse generalized edema of lungs; anthracosis; hydro  thorax, bilateral; dilatation  of the heart; hyperenia of laryngeal and tracheal mucosa; cloudy  swelling of liver and kidneys. 
  External appearance.- Marked cyanosis of ears, lips, and  fingers,  and extensive lividity of all dependent  parts. Frothy serosanguineous discharge exudes from the mouth and  nostrils. The skin shows no burns, scars,  wounds, or abrasions. The eyes are clear, the lids edematous. 
      Gross    findings.- Lymph glands are small. Lungs: Do not collapse and  completely fill the pleural cavities.  They show the imprint of the ribs. Right pleural sac contains 200 c. c.  of serosanguineous watery exudate; the pleura  is everywhere smooth and glistening. The left is like the right. The  lungs are heavy and boggy, and when cut show  an extremely wet surface. There is much anthracotic pigmentation.  Several accumulations of air appear subpleurally  over the surface, and the lung markings are emphysematous. Neck    organs: There is moderate hyperemia of the  mucosa of the pharynx and trachea, but no edema, tumefaction,  exudation, or ulceration. The trachea shows slight  hyperemia but no further change. It is filled with frothy  serosanguineous fluid, which exudes in quantity when the  lungs are pressed. Heart: Enormously dilated, especially the right  auricle and ventricle, which are three times their  normal size and filled with dark clotted blood. Liver: Intense  congestion and cloudy swelling. Spleen: Four times  normal size and very firm. Kidneys: Congestion and cloudy  swelling. Gastrointestinal tract: Not recorded. 
      Microscopic examination.- Trachea: Lined with a single row of nonciliated  cells, which are in some places  completely exfoliated. The superficial cells have been desquamated.  There is no edema or leucocytic infiltration of  the submucosa, but the membrana propria unquestionably is thicker than  normal. Lungs: Sections show advanced  post-mortem changes, and finer details can not be made out. There are  scattered patchy areas of edema. In some of  the alveoli are many polymorphonuclear leucocytes, in the majority, the  cellular elements are scanty and composed  chiefly of desquamated epithelial cells containing pigment, red blood  cells, and occasional leucocytes. Gram-positive bacteria are fairly  numerous. There is little fibrin. Interspersed amongst the edematous  and pneumonic areas  are patches of collapse and emphysema.
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  NOTE.-The  gross findings are very typical of acute poisoning by phosgene or  similar  suffocant gas, and confirm the clinical diagnosis. The histological  material is of little value for  finer study. 
  
  CASE 5.- H. E. McH., 3173285, Pvt. Co. H, 16th  Inf. Died, October 4, 1918, Evacuation Hospital No. 6.  Autopsy, October 5, 1918,--hours after death, by Capt. James F.  Coupal, M. C. 
      Clinical    data.- Mustard-gas burns and  inhalation. Died while being evacuated. 
  Anatomical diagnosis.- Extensive superficial burns. Diphtheritic  tracheobronchitis. Bronchopneumonia  (bilateral). 
  External    appearance.-Cloudiness of cornea and  conjunctive. Burns of face, hands, elbows, and back. 
      Gross findings.- Pleural cavities: Left contains  40 c.  c. of cloudy fluid. Right, negative. Heart: Right  ventricle and auricle dilated. Otherwise normal. Lungs: Do not  retract on opening chest cavity. Left: Early pleurisy  over posterior portion. Lung on section is purple and yields quantity  of blood and frothy mucus. Both lungs show  areas of congestion and beginning consolidation  scattered throughout. Trachea: Contains a false membrane which  hangs to the wall and is surrounded by a quantity of thick mucus. Gastrointestinal    tract: Negative except for  injection of small intestine. The remaining organs are normal. 
      Microscopic    examination.- Trachea and larger bronchi are covered by  thick pseudo-membrane which is  made up of a fibrinous network in the interstices, in which are  numerous polymorphonuclear leucocytes. The  mucous glands show epithelial degeneration, possibly in part post  mortem. The cartilages are normal. Lungs:  Marked injection of all blood vessels, including the alveolar  capillaries. In some areas the alveoli contain an  eosinophilic granular debris, and the exudate is frankly inflammatory,  the alveoli being filled with plugs of fibrin and  leucocytes or merely leucocytes. Some alveoli contain large epithelioid  cells which are filled with brown pigment.  The smaller bronchi are acutely inflamed. Some contain a fine, purulent  pseudo membrane, or a covering of  leucocytes. Around one bronchus is an especially marked zone of  congestion, and even an infiltration of red blood  cells into the adjacent alveoli. Liver: Shows extensive fat  infiltration. The remaining organs are free from significant  changes. 
  
  NOTE.-The case is a typical one of early  mustard-gas poisoning, with very extensive  tracheobronchitis and early bronchopneumonia, dying on the second day  after exposure. 
 CASE  6.- W. D. F., 3173197, Pvt., Co. H, 16th Inf. Died, October 4, 1918,  at 2.20 p. m., Gas Hospital,  Julv ecourt. Autopsy, October 4, three and one half hours after death,  by Capt. James F. Coupal, M. C. 
      Clinical    data.- Mustard gas on the morning of October 2, 1918. 
  Anatomical    diagnosis.- Multiple burns of skin; necrosis of tracheal and  bronchial mucosa;  bronchopneumonia; pulmonary edema. 
  External  appearance.- Burns of face, neck, left hand, elbows, buttocks,  and  scrotum. 
      Gross    findings.- Pleural cavities: The right pleural cavity contains 50  c.  c. of clear fluid. Left, negative. Lungs: Contract only slightly. Pericardium: Contains 40 c. c. of  clear fluid. The right heart is markedly dilated; left,  in contraction. Otherwise negative. Lungs: The parenchyma of  both lungs is congested. In the right middle lobe near  the anterior border are patchy areas of atelectasis and  bronchopneumonia in a stage of gray hepatization. Also a few  areas of consolidation in right lower lobe. In the posterior portion of  the left lung in both lobes are several deeply  congested dark-red areas, somewhat resembling infarcts. The  unconsolidated portion of the lung yields a quantity of  frothy fluid. Mucosa of trachea appears necrotic and when stripped  leaves an injected wall. The smaller bronchi  contain a rather thin purulent exudate. 
      Microscopic    examination.-Trachea: The epithelium is lost save for a single row  of cuboidal cells here and  there, and the epithelium of the ducts of the mucous glands which tends  to creep over the adjacent tissue. The  submucosa is slightly edematous. The nuclei of the connective tissue  cells and of the wandering cells (chiefly  polymorphonuclear leucocytes) which infiltrate the tissue in moderate  numbers, are distorted and caryorrhectic. The  blood vessels are rather wide and contain unaltered cells. Mucous  glands normal. Lungs: Areas
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  of lobular pneumonia with foci of necrosis,  patchy alveolar edema, and an excess of leucocytes in capillaries.  (Fig.  27.) There is marked congestion and hemorrhage. The alveolar epithelium  appears to be largely desquamated. It can  rarely be made out distinctly. Bacteria are quite numerous,  predominantly Gram-positive diplococci in the alveolar  exudate and walls. Long chained streptococci and Gram-negative cocci  and bacilli are also found, especially in  bronchi. Bacteria are particularly numerous in the areas of necrosis.  Fibrin is not abundant in the exudate, but is  often present in the walls of the alveoli, apparently outside the  capillary walls. A very interesting feature of the  section is that many of the atria and alveoli are lined with a hyaline,  wavy, refractile band, which in Gram-Weigert-safranine preparation  stains bluish but has not the definiteness of fibrin. (See Pl. VI) No  alveolar cells overlie this  membrane. It is difficult to make out whether it is swollen fibrinous
  
  FIG. 27.- Case 6. Mustard-gas burn, 2    days'    duration. Lung showing patchy alveolar edema, stasis of      leucocytes in      capillaries, beginning lobular pneumonia, with areas of necrosis,      dilatation of atria  
  exudate, the membrana propria of the    alveolar epithelium, or the hyaline necrotic alveolar    epithelium itself. In favorable places it is seen to be raised up from    the alveolar capillary,    polymorphonuclear leucocytes and red blood cells being found beneath    it, as well as in the    alveolar space. Liver: Normal. 
  
  NOTE.- Definite  history of mustard-gas poisoning, patient dying on second day. Typical  mustard-gas burns. Lesions of the upper respiratory passages were  rather superficial. Pneumonia was of the influenzal type, with  hemorrhagic edema and hyaline necrosis of the  alveolar and bronchial walls. Bacterial infection was already  established.
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  CASE 7.- V. O., 134765, Pvt., Battery B, 2d  Mass. F. A. Died, October 13,1918, Julvécourt Gas  Hospital. Autopsy, October 13, at 2 p. m., by Capt. James F. Coupal,  M. C.
      Clinical data.- Gassed with mustard gas 48 hours  before  death. Marked dyspnea. 
  Anatomical    diagnosis.- Multiple superficial burns of skin; acute ulcerative  tracheitis; purulent bronchitis; bronchopneumonia;  acute fibrinous pleurisy; acute parenchymatous nephritis; mustard gas  poisoning. 
  External appearance.- Marked post-mortem lividity. Burns of  conjunctive, corneae, axillae, elbows, and  scrotum. 
      Gross    findings.- Heart: Markedly enlarged, right heart dilated. Muscle  pale. Lungs: Retract only slightly  upon opening the pleural cavity. Few fresh fibrinous adhesions over  major portion of both lungs. Both lungs  markedly edematous, especially in the posterior part, with the  alternating areas of consolidation, congestion, and  emphysema, the last especially along the anterior margins. Quantities  of dark-red blood and frothy mucus can be  scraped from the surface. Neck organs: Base of tongue and  larynx are markedly congested. Mucosa of trachea is  necrotic. Lumen filled with purulent exudate. Same condition extends  throughout bronchial tree. Gastrointestinal    tract: Not recorded. Liver, spleen, and kidneys show marked  congestion. 
      Microscopic examination.- Trachea: Epithelium is desquamated  over surface of mucosa except for a few  flat epithelial cells in one area. Epithelium of gland ducts, however,  though damaged, is more or less intact. A little  fibrinous pseudo membrane is present. This is infiltrated with  polymorphonuclear leucocytes and attached to the  submucous layer. The latter is congested, edematous, and infiltrated  with polymorphonuclear leucocytes, especially  the superficial zone. The nuclei are caryorrhectic. The mucous glands  and the deeper layers are not involved to the  same extent. A few capillary thrombi are present. Lungs: The  sections show no large bronchi, but some branches  show desquamated epithelium and contain detritus and leucocytes. The  alveolar walls are everywhere congested.  Capillaries are distended with blood and contain leucocvtes in excess.  In one section the alveoli contain granular  debris in which are large epithelioid cells with relatively small  spherical nucleus, often containing brown pigment in  the cytoplasm, and are accompanied by mononuclear and polymorphonuclear  leucocytes and little fibrin. There is  also more definite bronchopneumonia. Gram-stained sections show great  numbers of streptococci. Skin: Entire layer  of stratified squamous epithelium has been raised from the subcutaneous  surface except for small areas near the  mouths of the hair follicles. This portion of the epithelium is thin  and the cells distorted and deeply pigmented. The  subepithelial layer contains inflammatory cells of various types, some  of which show abundant chestnut-brown  pigment. Capillaries are congested, and elsewhere vessels are  surrounded by small round cells. Sebaceous glands  and hair follicles are not much affected. Sweat glands are normal. Liver:  Congested and atrophied with central fat  infiltration. Spleen and kidneys are negative. 
  
  NOTE.- Mustard-gas  poisoning, death after 48 hours, with skin burns. There was necrosis  of the epithelium of the trachea and bronchi, with very little membrane  formation. There was  early lobular pneumonia, probably streptococcal. 
  
  CASE 8.- O.  K. McD., 45325. Pvt., Co. L, 18th  Inf. Died, October 5, 1918. Autopsy at Evacuation  Hospital No. 7, on following day, by Capt. James F. Coupal, M. C. 
      Clinical    data.- Gassed October 3, mustard-gas shell. No autopsy protocol. 
      Gross    findings.-(The following note of lesions of the respiratory  tract  was made at the pathological  laboratory of the experimental gas field.) The epiglottis and larynx  show no edema. Mucous membrane of trachea  and large bronchi is reddened. There is no evident necrosis, exudate,  or false membrane. The lymph nodes at the  bifurcation are calcareous, showing obsolete tuberculosis. Left lung:  Over the upper lobe are organized apical  adhesions. There is a small area of collapse near the anterior border.  On section there is moderate general edema and  congestion. At the base of the lower lobe there is a circumscribed dark  red area of consolidation about 3 cm. in  diameter. The lower lobe is somewhat more edematous, congested  posteriorly, with small patches of collapse  scattered throughout the lung. Near the base is an area of  consolidation somewhat graver than that in the upper lobe. Right lung: The upper lobe shows edema and congestion, with a  few small areas of consolidation near the hilus. The  middle lobe is congested posteriorly, and anteriorly there are areas of  atelectasis. There are a few small pneumonic  areas in the base of the lower lobe. Sonic of the bronchi are found  filled with thick mucopurulent exudate and  surrounded by a narrow zone of collapse.
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  Microscopic examination.- Lung and trachea: There is a pseudo membrane present and the  epithelium is  destroyed. The submucous layers are edematous and infiltrated with  polymorphonuclear leucocytes. The smaller  bronchi are similarly inflamed but there is no pseudo membrane. The  epithelium is intact in some bronchioles but the  lumina contain masses of pus cells. The lung parenchyma is edematous  and congested. The alveolar capillaries are  infiltrated with leucocytes, some of which have wandered out into the  alveolar spaces. In the alveoli are present also  red blood cells, pigmented epithelial cells, and occasionally a small  amount of fibrin. There is hyaline fibrinous  material deposited in places in the alveolar septa. Skin: The normal  epithelial covering is destroyed except around  the mouths of two hair follicles. Even  here the basal cells are in the process of vacuolization, elongation,  and  destruction, while the overlying layers are flattening out and  disappearing. On the surface there is noncellular  cornified membrane underneath which is a collection of red blood cells,  leucocytes, and detritus, while the base of  this blister is formed by the subcutaneous tissue, infiltrated by  polymorphonuclear leucocytes, and is edematous. Liver, spleen, and kidneys show no significant lesions. 
  
  NOTE.- Mustard-gas  poisoning, with typical skin lesions, death occurring on the second  day after exposure. The respiratory lesions are rather indefinite and  the histological description  does not correspond with the gross findings, particularly as regards  the presence of a  membranous necrosis in the bronchi. 
  
  CASE 9.- C.  H. W., 101135, Pvt., R. A. F., 3  Kite Balloon Section. Died, October 23, 1918, at 7.05 a. m.,  at Base Hospital No. 2. Autopsy, two hours after death, by Capt. B. F.  Weems, M. C. 
      Clinical data.- October 21, 1918. Admitted to No. 47  Casualty Clearing Station, with gas-shell wound of  right leg and groin. Gassed. October 22, admitted to Base Hospital No.  2. Face badly burned; eyelids edematous;  slight cyanosis and dyspnea; rattle of moisture in trachea and bronchi;  pulse 120. Chest: Good resonance, bronchial  and tracheal rales. Heart: Cardiac dullness within normal  limits. Abdomen: Superficial wound in epigastric region. Abdomen soft. Penetrating wound of left groin.  Through-and-through wound of right thigh. October 23. No change  in condition. Died suddenly at 7.05 a. m. 
  Anatomical    diagnosis.- Extensive first and second degree burns of skin; acute  conjunctivitis; membrano-ulcerative pharyngitis and tracheitis;  laryngitis; membranous bronchitis; lobular pneumonia; congestion and  edema  of lungs; interstitial emphysema of lungs; acute fibrinous pleurisy,  left; chronic fibrous pleurisy over right upper  lobe; congestion of abdominal viscera; gas-shell wounds of both thighs. 
  External appearance.- Extensive burns over the trunk and  extremities and large, pale-yellow blebs upon the  anterior surface of both thighs, about the left knee, upon both  forearms, and upon the neck and face. Besides these  clear bullae, there are large areas of a peculiar dusky,  pinkish-purple color, in most cases adjacent to the bulla and  having approximately the same distribution. The face is swollen and  covered over the beardy portions by scabby  exudate; the skin about both eyes is swollen and discolored; there is  purulent conjunctivitis. A mucopurulent exudate  issues from the nostrils. There is extensive gingivitis. Skin over  scrotum and penis edematous and in part blistered.  Wounds: There is a through-and-through wound of right thigh, external  to femur; wound of entrance just beneath  anterior superior spine. 
      Gross findings.- Lungs: Marked inflation, anterior edges  overlapping to level of third rib. Fibrous adhesions  over right apex, no fluid in pleural cavities. Right, voluminous, color  gray, becoming pink near posterior portion.  The organ crepitates throughout. There are a few small slightly nodular  areas in lower lobe. On section through  upper lobe some small slightly sunken areas of a deep-red color are  revealed, and a few small, rather cheesy plugs in  the small bronchi. The lower lobe presents the same picture, except  that there are a few patches of incomplete  consolidation in lower portion and somewhat more congestion. Left,  likewise voluminous, rather heavier than right,  pleural surface shows a very slight fibrinous exudate, especially over  anterior part of upper and lower lobes. There is  some interstitial emphysema, most marked upon the anterior flap of  upper lobe. The organ is closely nodular. There  are lobular elevations over the anterior and inferior portions of upper  lobe as well as lower. Upon section, surface is  very moist, exuding bloody serum. There is patchy and extensive but  incomplete consolidation. There are sunken  brownish-red areas about the smaller bronchi. The bronchi themselves  stand out sharply from the surrounding
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  tissue and appear almost occluded by  fatty-looking plugs of exudate. Upon dissecting the larger bronchi  these are  found to contain large fatty looking casts coextensive with the  tracheal membrane and extending downwards into the  smallest bronchial tubes. Organs of neck: Tongue and regions  about tonsils appear normal. The uvula is edematous  and mucous membrane slightly macerated. The posterior pharyngeal wall  is inflamed, with a slight fibrinous  exudate. The laryngeal surface of the epiglottis and the epiglottic  folds are edematous, deeply injected, and covered  by a somewhat patchy grayish-yellow membrane. There is considerable  erosion of the mucous membrane over both  true and false vocal cords. The trachea is covered by a yellowish-gray  necrotic membrane. Upon lifting the edge of  this and stripping it back one has the impression of separating the  mucous coat. The underlying surface is finely  granular, with minute points of capillary hemorrhage. This membranous  lesion extends down into the primary  bronchi. The peribronchial glands are not enlarged. Heart normal. Gastrointestinal tract normal. Remaining organs  show no significant lesions. 
      Microscopic    examination.- Skin: The section shows definite necrosis, as  evidenced by pink-staining  cytoplasm, pyenosis of nuclei, vacuolization, separation of individual  cells. There is loosening of the keratin lamellae. The section passes  through the edge of a vesicle filled with shreddy fibrinous coagulum.  The separation appears  to have taken place within the epidermis, and not between epidermis and  corium. The superficial layer of the corium  is moderately edematous and contains a few pycnotic wandering cells.  There is no marked hyperemia; no thrombosis  and no striking alteration of the vascular endothelium. Primary    bronchus: Lined with a thick fibrinous membrane, in  places distinctly laminated and containing polynuclear leucocytes,  especially on the surface. The ciliated mucosa is  still present beneath the membrane, though largely detached from the  basal layer of cells. The nuclei of these  detached cells are perhaps somewhat pycnotic, but there is no very  evident necrosis. The membrane is attached at  intervals by vertical fibrinous strands to the submucosa. The ciliated  cells are separated from the basal row in places  by fresh hemorrhage. The submucosa is very edematous, fibrinous,  hemorrhagic, with moderate cellular infiltration.  The mucous glands are flattened and do not appear to be actively  secreting. Medium-sized bronchus: Shows similar  changes, except that the lumen is completely filled by a loose  fibrinopurulent exudate. An attached bronchial lymph  node shows the sinuses filled with pus and fibrin. Lungs: There  is marked subpleural and interlobular edema. The  capillaries are universally congested. There is a patchy, very loose  exudate into the alveoli, composed of well-preserved mononuclear and  polymorphonuclear leucocytes, few erythrocytes, and occasional swollen  and exfoliated  epithelial cells. Two small bronchi in the section show an intact  mucosa. There are scattered emphysematous  vesicles. Liver, spleen, kidney, pancreas, and adrenal show no  significant lesion. 
      Bacteriological    report.- Blood culture (post-mortem) anaerobic media streptococcus  hemolyticus, aerobic  in second generation. Lung culture: Pneumococcus, type(?); micrococcus  catarrhalis. 
  
  NOTE.- A  very characteristic case of poisoning with mustard gas, probably dying  on the  second day after exposure. There were extensive skin burns, and a  severe membranous necrosis  of the upper respiratory tract. The lung showed an early patchy lobular  pneumonia, with areas of  edema. There are no features deserving special comment except, perhaps,  the preservation of the  tracheal epithelium, which is included in the fibrinous membrane. 
  
  CASE 10.- B.  B., 2252004, Pvt., Co. A, 39th  Inf. Died, October 14, 1918, 10.45 a. m., Base Hospital No.  58. Autopsy, October 15, 23 hours after death, by Capt. M. Flexner, M.  C. 
      Clinical    data.- Gassed October 11, 1918, admitted to Base Hospital No. 58 on  same day. Semicomatose, no  history obtainable. Tincture digitalis and oxygen inhalation. 
  Anatomical    diagnosis.- Mustard-gas poisoning. Bronchopneumonia. 
  External    appearance.- Cyanosis of face and ears. Two superficial blisters on  forehead about 3 cm. in  diameter. Superficial burn on bend of left elbow. No other cutaneous  lesions. 
      Gross    findings.- Pleural cavities: The right is free. The left is  obliterated by old fibrous adhesions. Pericardium: Contains about 20 c. c. of clear fluid. Heart:  Left ventricle is contracted; the right is flabby; no other  lesions. Right lung: Has old fibrous adhesions between the  upper and middle lobes. Left lung: The pleura presents a  shaggy appearance
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  over both lobes. Lung feels cottony with the  exception of a few calcified areas. In the upper lobe is a small patch  of  bronchopneumonia about 2 by 3 cm. In general the cut surface is dry,  mottled pinkish red in color. Purulent  bronchitis, somewhat less marked than in right lung. Larynx,    trachea, and large bronchi are injected and contain  thick yellow pus. Gastrointestinal tract: Normal. The remaining  organs show no significant lesions. 
      Microscopic examination.- Trachea: The epithelium for the most part is  desquamated. (This may be largely  post-mortem, autopsy 23 hours after death.) In places there is a layer  of squamous epithelium which seems to  originate from the glandular ducts. There is a moderate leucocytic  infiltration of the submucous tissue, with  congestion and edema. The leucocytes in the superficial zone are  caryorrhectic. Section through medium-sized  bronchus shows complete necrosis of epithelium and formation of  definite membrane. Lung: Terminal bronchioles  and alveoli are filled with exudate composed of polynuclear cells. In  some areas red cells predominate and moderate  numbers of pigmented epithelial cells also are seen There are small  areas of emphysema and atelectasis. Alveolar  capillaries are also congested. In sections stained by Gram method very  few bacteria are seen. Skin: There is  desquamation of the epidermis and remains  of an old bleb. Slight leucocytic infiltration in subepithelial layer  and  some fibroblastic activity. There are a few polymorphic pigment cells. 
  
  NOTE.- A  case of mustard-gas poisoning of three days' duration. Slight burns of  skin;  inflammatory changes of trachea and larger bronchi were rather  superficial. No membrane  except in smaller bronchi. Parenchyma of lung was very little affected. 
  
  CASE 11.- J. L. J., 2388735, Pvt., Co. M, 4th  Inf. Died, October 17, 1918, 7 a. in., at Evacuation Hospital  No. 6. Autopsy, three hours after death, by Capt. James F. Coupal, M. C. 
      Clinical data.- Mustard-gas burns and inhalation. Gassed  on  October 14. Area shelled daily with Yellow,  Blue, and Green Cross shells; prolonged stay in contaminated vegetation  and shell holes. 
  Anatomical    diagnosis.- Multiple superficial burns of body with mustard gas.  Acute ulcerative tracheitis and  bronchitis. Bronchopneumonia. Acute fibrinous pleurisy. 
  External    appearance.- Burns of face, scalp, conjunctivae, left shoulder,  arm, and axilla, scrotum, and  buttocks. 
      Gross    findings.- Pleural cavities: Contain each about 200 c. c. of clear  fluid. Few fresh fibrinous adhesions.  Lungs: Both present a similar appearance, showing alternating areas of  emphysema, edema, and congestion. On  section they yield quantities of dark blood and frothy fluid. Posterior  portions are especially edematous; anterior  margins emphysematous. Organs of neck: Base of tongue, fauces,  pharynx and larynx are markedly congested.  Moderate edema of glottis. Trachea: Throughout is denuded of mucosa. Bronchi: There is a loose membrane which  extends from the trachea into the larger bronchi. Secondary bronchi  contain purulent exudate. 
      Microscopic examination.- Trachea: There is an adherent fibrinopurulent slough  in which is incorporated a  necrotic submucosa. Coarse network of fibrin, with many distorted and  fragmented nuclei and superficial masses of  bacteria, composes the exudate. Here and there the surface is covered  by a layer of flattened cells, the connection of  which with the proliferating cells of the mucous ducts does not appear  in the section. The fibrinous edema and  leucocytic infiltration of the fibrous tissue extends quite deeply.  There is extensive congestion but little or no  hemorrhage. Some of the glands show excessive mucous secretion; others  are exhausted. Lung: Bronchi are filled  with purulent exudate. Epithelium is largely preserved. Wall moderately  congested and hemorrhagic. There is a fine  fibrinous exudate in the surrounding alveoli. In these plugs of exudate  are large well-preserved epithelioid nuclei,  probably derived from alveolar cells. The alveolar epithelium under the  immersion shows interesting changes. It is  swollen and vacuolated. In many places there is an active growth of  epithelial cells which creep along the alveolar  walls or follow fibrin strands to invade or cover the plugs of exudate.  In these places one finds the remains of the  original epithelial lining. This epithelial reaction is the most  striking feature of the section. Liver and spleen show no  lesions of interest.
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  NOTE.- Case  of typical mustard-gas poisoning, with extensive diphtheritic necrosis  of  trachea and bronchi and characteristic peribronchial reaction. There  were interesting regenerative  changes in the alveolar epithelium. 
      CASE 12.- J. R., 134681, Pvt., Co. B,  102d F. A. Died, October 13, 1918, 3 p. m., Evacuation Hospital No.  6. Autopsy No. 54. Autopsy, October 14, 19 hours after death, by Capt.  James F. Coupal, M. C. 
      Clinical data.- Exposed on 9th and 10th  of October to gas shelling (mustard gas and chloropicrin) over a  period of five and one-half hours, 2,000 105-mm. and 150-mm. shells  used over small area. Masks were removed  too soon and soldiers slept in a gassed area. Diagnosis of mustard-gas  poisoning. 
  Anatomical    diagnosis.- Multiple  mustard-gas burns of skin; acute  ulcerative tracheitis; purulent bronchitis;  bronchopneumonia; fibrinous pleurisy; acute parenchymatous nephritis. 
  External  appearance.- Burns of face, neck,  conjunctive, cornea-, elbows, axille, and scrotum. 
  
  Gross  findings.- Pleural cavities: Lungs retract very slightly on  opening the thorax, The right contains 400 e. c. of fluid with many  fresh fibrinous adhesions. 
  (The    following note was dictated at the pathological laboratory,    Experimental Gas Field.) 
  Respiratory    organs.- Trachea and bronchi are intensely congested. There is no    membrane. Right lung: The upper lobe is voluminous and    congested    and markedly edematous.    Middle lobe shows confluent lobular consolidation, affecting the entire    lobe, with much    fibrinous exudate about the pleural surface. The lower lobe shows    extensive pneumonic    consolidation, confluent in the lower portion. Left lung: Both    upper and lower lobes are    moderately congested and edematous and are free from pneumonic    consolidation. Alimentary tract: Not examined. Kidneys: Cortex is mottled,    alternately pale and hemorrhagic. The capsule    is somewhat adherent. Vessels engorged. The remaining organs show no    significant changes. 
      Microscopic    examination.- Trachea: Shows complete loss of epithelium, with necrosis of    the superficial portion of the submucosa. Associated with the    leucocytic invasion, there is a    fibrinous exudate and capillary hemorrhage. Nuclei of leucocytes show    marked caryorrhexis.    There is no false membrane. Epithelium of the ducts is conserved and in    part widened. Mucous    glands are degenerating. Bronchus: There are a few shreds of    apparently proliferating epithelial    cells beneath the fibrinopurulent membrane. Edema is intense. The    bronchial    wall is congested    and there is early proliferation of the fibroblasts. Lung: Alveoli are    very large. Many are partially    filled with dense leucocytic exudate. Some edema of the interlobular septa and about the    bronchi. There is also patchy alveolar edema. In the nonconsolidated    areas there is marked    congestion, with extensive exfoliation of the alveolar epithelium.    Gram-stained section shows    many Gram-positive cocci, morphologically staphylococci, occurring in    groups in the alveolar    exudate. Kidney: Shows    acute hemorrhagic nephritis. There are no inflammatory lesions in the    glomeruli. There is considerable epithelial necrosis, some of which may    be autolytic. Liver and spleen show no significant lesions. 
  
  NOTE.- The  lesions ate sufficiently typical of early mustard-gas poisoning  (duration 3  days) except for the presence of an acute hemorrhagic nephritis. It is  interesting to note that  McNee recorded one case of hemorrhagic nephritis in his series of 18  mustard-gas cases. 
  
  CASE 13.- A.  J. L., 1426227, Cpl., Co. G, 30th  Inf. Died, August 13,1918, at 3.30 p. m. at Base Hospital  No. 27. Autopsy, one and one-half hours after death, by Capt. H. H.  Permar, M. C. 
      Clinical    data.- August 10, admitted to Field Hospital No. 7. Diagnosis:    Exposure to    mustard gas. Eyes irrigated; soda bath. Transferred at 6.30 p. m. to    Evacuation Hospital No. 6.    August 12, admitted to Base Hospital No. 27. Surface burns of back and    genitals, edema of    lungs, rapid, weak heart. August 13, died at 3.30 p. m. Clinical    diagnosis: Inhalation of    deleterious gas, mustard gas and phosgene (?).
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  Summary  of gross lesions.- Excoriations and second-degree burns of skin  back and genitals. Both pleural  cavities empty. Left lung:  Weighed 960 grams; upper lobe congested and  edematous, lower lobe shows peribronchial  consolidation. Right lung:  Weighed 70 grains; areas of consolidation in  all lobes, which are markedly congested.  Completed destruction of mucosa of primary bronchi. Right side of heart  dilated. 
      Microscopic    examination.- Trachea and large bronchi: No material  preserved. Lung: The medium-sized  bronchi show complete epithelial necrosis, with the formation of  fibrino-purulent plugs, in some cases occluding the  entire lumen. The epithelium in a few of the bronchi shows early  regeneration. The bronchioli have an intact  epithelium, normally ciliated, but contain purulent exudate. So also  the atria. The lung tissue itself is the seat of  confluent lobular pneumonia, the exudate in places being cellular, in  others more fibrinous There are no distinctive  features. 
  
  NOTE.- An  incompletely studied, but apparently typical case, of mustard- gas  poisoning  of three days' duration. There is nothing in the findings at autopsy to  confirm the clinical  suspicion of exposure to phosgene in addition to mustard gas. 
  
  CASE 14.- J. M. P., 1630061, Pvt., Co. H, 30th  Inf. Died, August 13, 1918, at 2 p.m. at Base Hospital No.  27. Autopsy No. 30, performed one and one-half hours after death by  Capt. H. H. Permar, M. C. 
      Clinical    data.- Gassed with mustard-gas shells at Chateau Thierry on August    10; admitted    to Field Hospital No. 7 on same day. Eyes irrigated with novocaine;    soda bath. August 12,    admitted to Base Hospital No. 27. Extremely cyanotic and dyspneic;    weak, rapid pulse; burns    over entire body surface. Lungs: Moist rales throughout.
      Summary of gross lesions.- Large blebs over back, chest, arms, face,  and genitals. Few old adhesions in  right pleura, left negative. Left lung: Weight, 466 grams;  scattered areas of emphysema, atelectasis and consolidation  in lower lobe; upper lobe congested. Bronchi filled with crust-like  yellow slough. Right lung weighs  530 grams;  voluminous, emphysematous, areas of consolidation in lower lobe.  Trachea ulcerated and covered with pseudo-  membrane. Right heart dilated.  Old tuberculous lesions in peribronchial  lymph-node. 
      Microscopic examination.- Medium-sized bronchus: There is  complete denudation of the epithelium; the  wall is formed by a dense granulation tissue, with distorted nuclei of  inflammatory cells. No membrane is included  in the section. The mucous glands are atrophic. Lungs: The  smallest bronchi are filled with purulent exudate; their  epithelium is intact. The alveoli contain a tense cellular exudate, the  pneumonic process being diffuse and confluent.  There are no special features. 
  
  NOTE.- An  incompletely described case of early mustard-gas poisoning of three  days'  duration showing the usual findings at autopsy. 
  
  CASE 15.- A. L., 547297, Pvt., Co. H, 30th  Inf. Died, August 13, 1918, at 5.30 a. m., at Base Hospital No.  27. Autopsy No. 29, performed three and one-half hours after death, by  Capt. H. H. Permar, M. C. 
      Clinical data.- August 10, exposed to mustard-gas  shelling. Admitted to Field Hospital No. 7. August 12,  admitted to Base Hospital No. 27, with diagnosis of mustard-gas  inhalation and contact burns of extremities, head,  and back. Cardiac failure. 
  Anatomical    diagnosis.- Burns of face, shoulders, back, chest, arms, thighs,  and  knees; pigmentation of skin  of scrotum; laryngitis, tracheitis, and bronchitis, mucopurulent, with  sloughing of mucosal lining;  bronchopneumonia, early bilateral; edema and congestion of lungs. Heart:  Dilatation of right side. 
      Microscopic examination.- Trachea: There is complete  destruction of the surface epitheliuzn, but that of the  ducts of the mucous glands is intact, and already actively  proliferating. There are small shreds of false membrane  adherent in places, but in general the trachea is lined by the necrotic  submucous tissue. The zone of necrosis extends  to the mucous glands, and the membrana propria is destroyed. In the  necrotic tissue are many wandering cells, with  pycnotic and distorted nuclei. The blood vessels are intensely  congested. The glands appear somewhat compressed  and flattened. Medium-sized bronchus: About the same picture as  in the trachea. In one area, the necrotic epithelium  in, the cells of
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  which have completely lost their    staining, is lifted up from the membrana propria by a collection    of leucocytes, forming a sort of pustule. A smaller bronchus shows in    addition very extensive    hemorrhage into the deeper portion of the submucosa. Lung: Bronchioli    show a suppurative    inflammation, but their epithelium is still intact.    There is an extensive lobular pneumonia,    without special features. The exudate is very cellular, and the    leucocytes well preserved. 
  
  NOTE.- A  very severe but typical case of mustard-gas poisoning of only three  days'  duration. An interesting point in the histological study of the trachea  is the early proliferation of  the epithelium of the mucous ducts. 
  
  CASE 16.- H. B., 2193795, Pvt., 314th F. S. B.  Died, August 11, 1918, at Base Hospital No. 116. Autopsy  by Lieut. B. S. Kline, M. C. 
  
  Clinical  data.- Gassed with mustard-gas August 7; admitted to Base  Hospital No.  116 on August 10, with  cyanosis and extensive edema; severe burns all over body. Right heart  dilated. Pulse rapid and weak. Treated with  stimulants and venesection. 
  Anatomical diagnosis.- Extensive gas burns, upper respiratory  tract. Superficial burns of skin, penis, and  scotum. Acute seropurtulent conjunctivitis. Pigmentation of skin of  face and scalp. Ulceration of mucosa of larynx,  trachea, and bronchi. Acute membranous laryngitis, tracheitis, and  bronchitis. Bronchopneumonia. Acute  lymphadenitis. Cloudy swelling of parenchymatous organs. Cardiac  dilatation, right side, moderate. Pulmonary  edema, slight. 
 
   External appearance.- Body is that of an adult male, 192 cm. in  length, well developed. Rigor is present to a  considerable degree in the voluntary muscles. There is a moderate  amount of hypostasis. In the skin of the back,  particularly over the left shoulder and left axilla and to a less  extent over the right scapular region; above this and  between the scapulae are large superficial  ulcerated areas. The base is clean and has a reddish-brown appearance.  There is a similar smaller ulcerated area in the left lumbar region.  There are others about the sacrum, the axilla on  each side, the right upper arm, and over the chest anteriorly,  particularly in the region of the ensiform. There is also  superficial ulceration about the prepuce, the anterior surface of the  scrotum showing a matted scab. These ulcerations are very superficial  and extend into the dermis only. At the bend of the left elbow there is  an area of  vesiculation several centimeters in length and about 6 mm. in width.  There is also another area on the left greater  trochanter, a few centimeters in diameter. At the hand of the right  elbow there is a superficial ulcerated area similar  to those described above, and in addition over the head of the ulna  there is an area of contusion. The skin of the face  and scalp have a brownish color. There are beginning vesicles about the  left side of the mouth. The inguinal glands  are somewhat enlarged. The mucous membranes are pale. Eyes: The  eyelids are somewhat swollen, the lids glued  together by tenacious mucopurulent material. The conjunctiva e are  edematous and there are patches of  injection of the bulbar conjunctiva. There is a slight cloudiness of  the cornea. The pupils, about 3 mm. in diameter,  equal. Nose: In the nose there is a moderate amount of  mucopurrulent material. Mouth: No abnormalities. Chest:  Well formed, costal angle about 900. Abdomen and extremities:  Natural looking. 
      Gross findings.- Pleural cavities: On opening the thorax the right pleural sac  is free of fluid and adhesions.  The left pleural sac is likewise free of fluid and adhesions. The heart  lies in normal position. On incising the  pericardial sac no abnormalities of or in the sac are visible. On the  ventral surface of the right ventricle there is  typical milky patch. Heart: Right auricle and ventricle  moderately dilated. Otherwise normal. Right lung: All lobes  voluminous, cushiony, somewhat soggy, palpable solid areas here and  there, most marked in the tipper and median  portion of the upper and middle lobes. The glands at the hilus are  somewhat enlarged, pulpy, pigmented, and  somewhat injected. Bronchus: The mucosa in the greater part  ulcerated. Covering the denuded submucosa there is an  elastic fibrinous membrane forming a cast of the bronchial tree. The  vessels at the hilus show no abnormalities  except perhaps some dilatation of the arteries. On section of the upper  lobe a moist pinkish-red surface presents. The  tissue is quite well aerated. In the air sacs there is a moderate  amount of the frothy fluid. Medially there are vaguely  outlined grayish-red solid patches varying ill size from a few  millimeters to a few centimeters in diameter.  Posteriorly the solid patches are fewer in number and the tissue is  well aerated. The middle lobe oil section  crepitates.
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  Medially there is a large walnut-sized,  solid, dull reddish-gray patch. Nearby there are other solid patches of  similar  appearance. In the smaller bronchioles in this lobe viscid purulent  exudate is visible. There is one peribronchial  lymph node, grape seed in size, surrounded by a firm pigmented zone. On  section of the lower lobe the tissue  crepitates. The tissue is well aerated. In the air sacs there is a  small amount of thin frothy fluid. The tissue is  somewhat congested. In the large bronchial branches there is an  adherent mass of exudate. On repeated section no  definite solid areas can be made out. Left lung: The glands,  vessels, and bronchi similar in appearance to those on the  right. The pleura here, as on the right side, is thin and delicate. The  lobes, as of the right, are very voluminous,  cushiony. On section they crepitate. In the median portion there are  good-sized reddish, dull gray areas of  consolidation. In the left lower lobe the purulent exudate in the  bronchioles is striking in amount. Neck organs: The  larynx is filled with tenacious viscid mucopurulent exudate, most  marked in the epiglottis and about the true vocal  cords. The pouch behind them likewise is filled with a viscid exudate.  The trachea is similar in appearance except  that the exudate lessens in amount toward the bifurcation. Here the  patchy ulceration of the mucosa is very striking.  Below it the submucosa is intensely injected. Attached to the tip of  the epiglottis there is an adherent elastic, friable  plug of exudate. Throughout the upper respiratory tract the submucosa  and the muscular coats are considerably  edematous. The thyroid of average size and consistency. On section the  tissue is spongy. The acini contain but a  small amount of colloid. The tonsils of fair size and project somewhat  above the general level. On section the tissue  in great part is scarred. There is but a small amount lymphoid tissue  present. The crypts are clean. Alimentary tract:  The upper end of the esophagus and the base of the tongue show  considerable injection of the mucosa. There is no  ulceration present, however, and no exudate. The stomach contains some  intensely bile-stained contents and a small  amount of mucus. In the mucosa there are scatted areas of patchy  injection. The duodenum shows no abnormalities.  In the lower ileum there are patches of patchy injection of the mucosa.  The solitary follicles are somewhat more  prominent than normal in the lower ileum. Patchy injection of the cecum  and of the transverse and descending colon.  The appendix shows considerable patchy injection of the mucosa with  tiny hemorrhages, especially marked in the  tip. Kidneys show cloudy swelling. 
      Microscopic    examination.- Lungs: No large bronchi are included in the sections.  There is dilatation and  hyaline necrosis of the walls of the infundibula. Small bronchioles  still retain their epithelium but their walls are  infiltrated with inflammatory cells. Alveolar walls are congested and  contain many leucocytes. There is typical  bronchopneumonia, the exudate being composed chiefly of well-preserved  polymorphonuclear leucocytes. There is  very little fibrin. Trachea: Well-formed laminated membrane  invaded with leucocytes and containing in one area a  large mass of mucus. Beneath the membrane in places a single row of  epithelial cells with pycnotic distorted nuclei.  Marked swelling of membrana propria. Edema, congestion, hemorrhage, and  leucocytic infiltration of submucosa.  The ducts of the mucous glands are distended with thick plugs of mucus.  The epithelium in the superficial portion is  destroyed. (Fig. 28.) 
      Bacteriological    report.- Smears made from the exudate in larynx show innumerable  organisms. The  predominating one, a Gram-positive lancet-shaped diplococcus. In  addition there are some rounded Gram-positive  cocci, also a moderate number of small and large Gram-negative bacilli  and a few Grain-negative cocci. 
  
  NOTE.- A  typical case of mustard-gas poisoning of four days' duration. There was  a  diphtheritic tracheobronchitis, with patches of secondary  broncho-pneumonia. Histologically the  lung lesions differ from the influenzal pneumonias in the absence of  extensive hemorrhagic  edema and in the presence of large numbers of leucocytes in the  exudate. There was, however,  hyaline necrosis of the walls of the dilated atria, such as was  commonly observed in the  influenzal pneumonias. 
  
  CASE  17.- A. H., 1940705, Pvt., Co. E, 20th Inf. Died, October 7, 1918, Gas  Hospital A. Autopsy,  October 8, four hours after death, by Lieut. Russell WV. Wilder, M. C. 
  
  Clinical  data.- Gassed on October 3, 1918. Burns of skin, eyes, and  respiratory  tract
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  Anatomical diagnosis.-  Hyperemia of mucous membranes of larynx,  pharynx, and trachea. Ulcerations of  mucous membrane of bronchi. Emphysema and beginning atelectasis of  lungs. Healed apical tuberculosis.  Parenchymatous degeneration of liver and kidneys. Second-degree  mustard-gas burns of face, arms, and trunk. 
  External    appearance.-Moderate cyanosis and lividity. Large vesiculated burns  of arms and trunk.  Desquamation of skin of scrotum, leaving raw bloody surface. Purulent  discharge from eyes. 
      Gross    findings.- Lungs: Distended. No free fluid in pleural cavities.  Pleura is smooth and glistening. Right,  crepitates throughout. On section reveals small bronchi occluded with  fibrinous exudate. Larger bronchi covered by  membrane, which, when stripped away, reveals longitudinal muscle  fibers. Extensive areas of emphysema and other  areas of beginning atelectasis. Left, shows similar picture. There is a  calcified scar 1 cm. in diameter in the apex of  the upper lobe. Heart: Right ventricle moderately dilated.  Mitral orifice somewhat stenotic, showing old endocardial  scars. Abdomen: Adhesions about the site of old appendectomy.  Gastrointestinal tract not examined. Pharynx  intensely congested. Larynx and tracheal mucosa hyperemic, but not  ulcerated or covered by exudate. Thin purulent  material in tracheal lumen.
  
  FIG. 28.- Case 16.    Mustard-gas    burn, 4 days'    duration. Trachea. Low-power view, showing laminated false      membrane attached to openings to mucous ducts
  
  Microscopic    examination.- Trachea. Tissue  poorly preserved. Epithelium  desquamated. Submucous layer  is edematotis, congested, and infiltrated with leucocytes. There is no  pseudo membrane. Section of medium-sized  bronchus shows complete destruction of mucosa, with formation of false  membrane composed of laminated fibrin. Lung: Sections unsatisfactory. Show only congestion of  capillaries and desquamation of mononuclear epithelial  cells. 
  
  NOTE.- A  typical early ease of mustard-gas poisoning, dying four days after  exposure.  There was a membranous inflammation involving the bronchi, more deep  seated than that in the  trachea and extending into the smallest branches. Parenchyma, of the  lung, aside from the  emphysema and atelectasis, due to occlusion of the bronchi was very  little affected.
  
  CASE  18- C. P., 3171057 (rank and organization  not given). Died, October 13, 1918, 11 a. m., Evacuation Hospital No. 6. Autopsy  No. 53. Autopsy, October 14. 27 hours after death, by Capt. James F.  Coupal, M. C. 
      Clinical data.- Gassed October 7 or 8. Died  while being  evacuated. Diagnosis: Mustard-gas poisoning. 
  Anatomical diagnosis.- Multiple superficial burns. Acute  ulcerative tracheitis; purulent bronchitis;  bronchopneumonia; acute fibrinous pleurisy; acute parenchymatous  nephritis.
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  External    appearance.- Burns of face,  neck, conjunetiva , cornea,  scrotum, buttock, and thighs. Multiple  blisters. Marked subcutaneous emphysema at base of neck and extending  down to first rib. Paraphiniosis. 
      Gross    findings.-Pleural cavities: Lungs retract very slightly. Left  pleural cavity contains 100 c. c. of sterile  yellow fluid. Right, a similar amount, with few fibrinous adhesions  over the diaphragm. Heart: The right ventricle is  dilated. 
  (Note  dictated at the pathological laboratory, experimental gas field.) Respiratory organs.-Trachea: Covered  with tough continuous membrane extending into the smaller bronchi. The  anterior portions of both lungs, including  the right middle lobe, are emphysematous, while the posterior portions  are congested and edematous. There are no  gross pneumonic lesions. Alimentary tract: Intestines injected  throughout. The remaining organs show no  significant lesions. 
  
  Microscopic    examination.- Trachea: Has a well-formed pseudo membrane composed  of  fibrin infiltrated  with polymorphonuclear leucocytes. Submucous layer is congested,  edematous and infiltrated with wandering cells,  showing beginning caryorrhexis. An interesting point is the presence  over large areas of a single row of epithelial  cells beneath the pseudo membrane and still attached to the swollen  membrana propria. The leucocytic infiltration is  not dense. There is beginning caryorrhexis and capillary extravasation.  The mucous glands do not appear to be in  active secretion. Bronchus: Section through a medium-sized  bronchus shows complete necrosis of the epithelium.  The lumina are filled with purelent exudate. Lungs: There are a  few small bronchi in the section showing generally  exfoliation of the epithelium, probably post-mortem. The alveolar  capillaries are congested, tortuous, and contain an  increased number of polymorphonuclear and large mononuclear cells. A  few air spaces are collapsed, others contain pink coagulum. There is slight  exfoliation of the alveolar cells. No pneumonia. Skin: The  epithelium is raised up  from the corium in a continuous sheet, forming a blister, the contents  of which consist of homogeneous, slightly  fibrinous coagulum with a fair number of leucocvtes, chiefly  polymorphonuclears. The epithelial cells show' varying  degrees of necrosis. The underlying corium is moderately edematous and  loosely invaded by wandering cells. The  vessels are not extremely congested and are free from thrombi even in  the superficial zone. Near the surface there  are small irregular cells containing pigment, some of which seem to  have been derived from the basal cells of the  rete mucosum. Some of the brown pigment has been taken up by the  polynuclears. At the margin of the blister the  epidermal cells are in places detached from their neighbors, and there  is considerable leucocytic infiltration,  especially in the zone just above the pigment layer. Papillary  processes are edematous. (See fig. 6.)
  
  NOTE.- Mustard-gas  case, five or six days' duration. There was a typical membranous  tracheobronchitis, in addition to the typical cutaneous lesions. The  pulmonary parenchyma,  according to the gross description and the single histological block  available, showed only  emphysema, edema, and congestion. There was no pneumonia.
  
  CASE  19.- D. B., 187, Pvt., 1/4 Highlanders R.  Died, October 23, 1918, at 5.10 a. m., at Base Hospital No.  2. Autopsy, four and one-half hours after death, by Maj. A. M.  Pappenheimer, M. C. 
      Clinical    data.- October 20, admitted to No. 5 Casualty Clearing Station,  with  diagnosis of shell-gas  poisoning (irritant). October 22 admitted to Base Hospital No. 2.  Patient is pale; breathing with much difficulty;  edematous; pulse 140, very weak; blood pressure 120-100). No sounds  during respiration. Sputum mucopurulent. Chest: Good resonance, tracheal and bronchial r?les. Heart:  Cardiac dullness within normal limits. Patient  received an intravenous dose of strophanthin at 7 p. in. Oxygen  administered, October 23. 4 a. m. Pulse very weak;  pale; thirsty. Died at 5.10 a. m. 
      Anatomical diagnosis.- Membranous tracheobronchitis; lobular  pneumonia; congestion and edema of lungs;  pleural adhesions; acute conjunctivitis; congestion of viscera. 
  External    appearance.- Conjunctiva are injected, slightly more so on left  side. Abundant thin watery  fluid flowing from mouth. The mucous membrane over the lower lip is a  little macerated There are no burns or other  cutaneous lesions.
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  Gross    findings.- Pleural cavities:  On both sides obliterated by organized  adhesions. Lungs meet in median  line to third interspace. Lungs: Voluminous and heavy, covered  everywhere with edematous sheet-like adhesions. In  all lobes there can be felt firm areas which are quite extensive. Right    lung: On section, upper lobe shows very  widespread areas of consolidation, which are grayish red and granular,  forming patches 2 or 3 cm. in size, between  which the lung tissue is very edematous and congested. The bronchi are  thick, the larger ones lined with a  continuation of the gray membrane present in the upper respiratory  passages, the smaller ones completely filled with  purulent fluid. In the lower and middle lobes the consolidation is less  extensive but of the same character. The  bronchi are surrounded by a sunken red zone. Left lung:  Presents a similar picture. The most extensive consolidation  is in the lower lobe, about two-thirds of which are completely  consolidated. Organs of neck: Tongue normal. Tonsils  small, normal on section. The pharynx congested, slight thickening of  the arytenoepiglottidean folds. On the  laryngeal surface of the epiglottis the mucous membrane in places is  denuded and covered by a thin grayish  membrane. The vocal cords and the entire lining of the trachea and  primary bronchi are covered with a coherent,  rather moist yellowish-gray membrane. This is readily detached, leaving  a swollen red velvety surface, apparently  covered by epithelium. Esophagus normal. Heart normal.  Remaining viscera, including gastrointestinal tract, show  no significant changes. 
      Microscopic examination.- Trachea: There is no membrane preserved in the  section. The epithelium is  reduced to occasional small groups of flattened cells, with pycnotic  nuclei. The membrana propria is swollen. The  submucous tissue is the seat of fibrinous edema. There is congestion,  scattered hemorrhage, and loose inflammatory  infiltration. The leucocytes as they approach the surface show pycnosis  and caryorrhexis. The edema extends  through the wall of the trachea to the neighboring fat and areolar  tissue. Primary bronchus: The section shows a  loose fibrinous membrane, to the base of which are attached strips of  exfoliated epithelium. There is a curious  arrangement of the fibrin. To the swollen membrana propria, are still  adherent in places, flattened, deeply staining  epithelial cells. The openings of the mucous ducts are dilated with  mucus and exfoliated cells. The edema,  congestion, hemorrhage, and leucocytic infiltration of the bronchial  wall are like that in the trachea. Tonsils: No  epithelial necrosis. Lungs: Bronchi filled with purulent  exudate which in the terminal infundibula are in the form of  fibrinopurulent plugs completely filling them. The epithelium is  preserved in part. There is diffuse pneumonia,  showing no special features. The exudate is rich in polymorphonuclear  leucocytes, showing early pycnosis. The  capillaries are extremely congested, and there is moderate diapedesis.  There is rather marked periarterial edema.  Another block shows a medium-sized bronchus, cut longitudinally and  completely occluded by a fibrinopurulent  plug. A few flattened epithelial cells persist here and there where the  plug is less firmly attached. The wall is  edematous and loosely invaded by wandering cells. The rest of the  section shows edema, patchy in distribution,  emphysema, and congestion. Liver, spleen, pancreas, and adrenals:  Show no special features. 
  
  Bacteriological    report.- Blood culture  (post-mortem) anaerobic  streptococcus, dying on transplant.  Staphylococcus aureus. Lung culture: B. influenza and  pneumococcus, Type IV. 
  
  NOTE.- This  case, probably one of mustard-gas poisoning of three or four days'  duration,  is interesting and unusual because of the absence of cutaneous lesions.  The diphtheritic necrosis  of the trachea and bronchi were very severe and extensive and could  hardly be ascribed to an  influenzal infection alone. There was, moreover, a definite history of  shell-gas inhalation. The  eye lesions appear to have been very mild. 
  
  CASE 20.- J.  A. A., 1681974, Pvt. (Co. not  given), 306th Inf. Died, September 29, 1918, at Base Hospital  No. 18. Autopsy No. 99, performed 16½ hours after death, by Lieut. B.  S. Kline, M. C. 
      Clinical    data.- Gassed on the night of September 25. Died shortly after  admission to Base Hospital No. 18.  No further data are available. The records at hand show four other  casualties from gas on the night of September 25  in the 306th Infantry. One thousand five hundred 77 and 105 mm. Yellow  Cross shells were used in the  bombardment, which lasted one hour.
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  Anatomical    diagnosis.- Gas burns of  scrotum, conjunctiva , and  respiratory tract; infected scrotal burn;  acute conjunctivitis; acute esophagitis; laryngitis, tracheitis, and  bronchitis; peribronchial and bronchopneumonia;  acute lymphadenitis, regional lymph nodes; healed pleural adhesions;  pulmonary edema, slight to moderate; chronic  diffuse nephritis; myocardial scars, left; hypertrophy of left  ventricle, considerable; anemia and emaciation, slight to  moderate.
  External appearance.- The skin is thin and sallow. The scrotum  shows an area of superficial necrosis of  the epidermis over each testis, also in the midline, several  centimeters in diameter. Over this there is matted serum  and a small amount of purulent exudate. The superficial lymph glands  are palpable. The conjunctiva are diffusely  injected. There is a small amount of fibrinopurulent secretion present;  both corne are cloudy. There is superficial  ulceration of the mucosa of the lips, covered with sores; many teeth  poorly formed. 
      Gross    findings.- Pleural cavities: Right pleural sac obliterated by  sheetlike adhesions. On the left side, no  abnormalities. Right lung: All lobes are voluminous, except the middle  lobe, which is smaller than the average. The  pleura in general is thickened. The lobes are bound to each other and  to the pericardium by fibrous bands. Vessels at  the hilum are normal. The lymph glands are enlarged, pulpy, injected,  and edematous. The bronchus shows a striking  picture; there is injection of the mucosa with patches of ulceration;  in many places fibrinous and fibrinopurulent  exudate adheres to the walls. On section of the upper lobe the tissue  in the posterior part shows slight congestion and  moderate edema. Throughout the lobe there are scattered areas of  peribronchial consolidation, varying in size up to a  few centimeters in diameter. In general they average only several  millimeters. The middle lobe in its greater portion  shows a patchy grayish-pink consolidation; about two-thirds of the  lobes are involved. The right lower lobe on  section resembles the upper. There is more uniform congestion, and the  consolidation is more distinctly  peribronchial. The bronchial branches throughout this side contain tightly adherent fibrinopurulent  exudate. Left    lung: Also voluminous in both lobes. The entire lung, except the  apex of the upper lobe feels soggy and solid. Over  the lower lobe posteriorly there is a small amount of fibrinous  exudate. Glands at the hilum, vessels and bronchi are  similar to those on the right side. On section of the upper lobe the  upper part is well aerated and pink, but contains a  few bronchopneumonic areas. In the lower portion there is considerable  edema, slight congestion, and scattered  areas of grayish consolidation, peribronchial and pneumonic. In the  median portion of the lobe there is an area of  consolidation several centimeters in diameter; the consolidation here  is almost uniform grayish and red, finely  granular. The lower lobe on section presents a picture similar to the  lower portion of the upper, but is more  extensive. The smaller bronchial branches are like those on the right  side. Organs of neck: The larynx is lined with a  necrotic white mucosa, covered in great part with tenacious, yellowish,  slightly green tinged, coherent exudate. The  true vocal cords and lower portion of the larynx are especially  affected. A similar condition is present throughout the  trachea, although the exudate is somewhat less abundant. Patchy  injection and superficial ulceration of the mucosa is  visible here and there. The posterior wall of the pharynx and the upper  esophagus present a picture like that in the  upper part of the larynx. The tonsils are slightly enlarged, edematous,  pale, and scarred. Heart: Weighs 320 grams,  the left ventricle about twice the average thickness. There are  myocardial scars, and the muscle is coarse in texture.  Sclerotic patches are seen in the coronaries and at the base of the  aorta. Kidneys: Reduced in size and show irregular  atrophy of the cortex and indistinct markings. Gastrointestinal    tract: Not described. Remaining viscera show no  changes of interest. 
      Microscopic    examination.- Trachea: Longitudinal section cut. There is complete  epithelial necrosis. Masses  of tightly adherent fibriniopurulent exudate, in which are many  bacterial colonies, cover the surface. The submucous  tissue is only superficially infiltrated with inflammatory cells. The  tissue is poorly preserved, and the red cells in the  vessels are not stained. Pharynx: On the surface is an adherent  fibrinopurulent slough; there is edema, intense congestion and inflammatory  infiltration of the submucous tissue. Lungs: Tile smaller  bronchi are lined with  adherent fibrinopurulent exudate which is incorporated in the wall and  does not form a distinct membrane. The  terminal bronchioles and infundibula are filled with pus; their  epitheliumn is still partially preserved. The  parenchyma shows a diffuse pneumonia; the exudate is of varying  composition, in places almost fibrinous, in others  containing dense aggregations of leucocytes. There are no features of  special interest.
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  The finer details are somewhat obscured by  formalin pigment. Another section shows circum- scribed areas of  pneumonia, in which there is great fragmentation of leucocytes and  abundant bacterial growth. The appearance  suggests beginning gangrene. Some of these consolidated foci are  surrounded by zones of hemorrhagic edema. There  is marked perivascular edema in some sections.
  
  NOTE.-Typical  early case of mustard-gas poisoning, of four days' duration, with  severe  diphtheritic necrosis of the upper respiratory passages.
  
  CASE  21.- A. B., 240806, Pvt., Co. L, 309th  Inf. Died, October 22, 1918, at 2.20 p. m., at Base Hospital  No. 15. Autopsy (time not given) by Maj. Daniel Glomset, M. C.
      Clinical data.- Gassed (inhalation and contact)  October  17, 1918. October 20, diagnosis of lobar pneumonia  right lower lobe was made. 
  Anatomical    diagnosis.- Bronchopneumonia, all lobes, pseudo membranous  tracheitis and bronchitis.  Parenchymatous degeneration of liver and kidneys. Second-degree burns  of skin. No detailed description of gross  lesions available. 
      Microscopic    examination.- Trachea: The membrane, only shreds of which  are  present, consists of coarse  fibrin network in which are scattered pycnotic leucocytes. Surface is  formed by the slightly swollen basement  membrane. The outer half of the submucosa is necrotic. There is a  coarse fibrinous exudate in the edematous tissue  with deeply staining nuclei. Vessels are congested but there is no  hemorrhage. The mucous ducts are apparently  obstructed at their orifices. They are dilated, as are many of the  mucous glands, and the epithelium is metaplastic, in  places showing regenerative changes. Lungs: There are small  patches of pneumonia definitely grouped about the  bronchioles and atria, in which are found the usual lesions. Uninvolved  lung is emphysematous. Kidney, myocardium, and adrenals show  no lesions of interest.
  
  NOTE.-Typical  case of mustard-gas poisoning of five days' duration, with membranous  tracheobronchitis. Lesions of the lung parenchyma are sharply limited  to the peribronchial  regions. It is of interest to note that regenerative changes in the  epithelium of the mucous ducts  are already in progress.
  
  CASE  22.- S. D., 2250618, Pvt., Co. I, 39th  Inf. Died, October 16, 1918, 8.30 a. in., at Base Hospital No.  59. Autopsy No. 7. Autopsy, four and one-half hours after death, by  Capt. M. Flexner, M. C. 
      Clinical data.- Gassed October 11, 1918.  Exposed to blue,  green, and yellow cross shells. Admitted to Field  Hospital the same day. Base Hospital No. 59 on October 13. On  admission, conjunctivitis, sore throat, pain in chest,  riles of all types throughout chest. Diagnosis of gas inhalation and  bronchopneumnonia. 
  Anatomical diagnosis.- Mustard-gas burns. Fibrinopurulent  tracheo-bronchopneumonia. Acute fibrinous  pleurisy. Emphysema. 
  External    appearance.- Skin about eves, nose, and mouth shows crusts from gas  burns. Scrotum shows dense  scab formation from old burns, and other severe superficial burns on  the elbows. Eyes show conjunctivitis, bilateral  keratitis. Cornea have steamed appearance. 
      Gross    findings.- Pleural cavities: Right lung: Pleural surface is  shaggy anteriorly, due to fibrous adhesions.  There are more recent adhesions between the visceral pleura and the  pericardial sac. Upper lobe is grayish white in  color with a few darker patches, especially at the apex, and the lobe  has a cottony feeling. On section, it is a pinkish-gray color with  scattered flesh-colored areas from one-half to 3 cm. in diameter. On  pressure bloody, frothy fluid  escapes. The base of lower lobe is firm and darker in color. Excised  piece of darker tissue sinks when placed in  water. Left lung: Pleura over lower lobe is covered with  fibrous tags. Upper lobe, on section, is pinkish gray in color.  Contains scattered flesh-colored areas. Around smaller bronchioles are  narrow dark colored zones. The upper two-thirds of the lower lobe are  reddish brown with a few scattered purplish areas, which are dry and  granular and  apparently contain no air. Lower lobe is pinkish gray in color with few  scattered elevations. Trachea and larger  bronchi show erosions of mucous membrane, with fibrin. The remaining  viscera show nothing of interest. 


