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Scientific Proceedings (ioo). 



exposure, constitute the microscopic features. On the conjunc- 

 tivae the epithelium shows pyknosis, hydropic degeneration, 

 liquefaction necrosis, or there may be a deeper necrosis extending 

 into the subconjunctival tissues. The conjunctival surface 

 suffers to a less degree proportionately than the epidermis. On 

 the mucous membranes the epithelium shows pyknosis, hydropic 

 or mucoid degeneration, desquamation, liquefaction or coagula- 

 tion necrosis. The necrosis may extend into the submucosa, 

 but the depth of the lesions on the conjunctivae and the mucous 

 membranes of the respiratory tract is never so great from identical 

 exposures, as it is in the skin. Following the necrosis there is 

 marked hyperemia, and the development of an edema, more 

 marked in the subcutaneous and subconjunctival tissues in 

 animals, but less marked in man. Human skin, however, shows a 

 much greater tendency to vesication. The blood vessels in the 

 necrotic area are killed, the blood cells hemolyzed to some extent 

 without thrombus formation or much extravasation, except 

 minute hemorrhages by diapedesis. Following the lesion there 

 is a demarcating inflammation, with slow regeneration, repair or 

 cicatrization. The regeneration of the epidermis proceeds from 

 the epithelium of the sweat and sebaceous glands. On the 

 mucous membranes there results in the severe cases a localized 

 eschar or ulcer, or a more diffuse diphtheritis. With secondary 

 infection the inflammatory process becomes purulent or suppura- 

 tive. The influence of secondary trauma and infection is well 

 shown in the early development of deep areas of decubitus in the 

 injured regions of the skin. Multiple furuncles may develop, or 

 large cutaneous areas become gangrenous. In the eye purulent 

 involvement of the anterior chamber, iris and ciliary body may 

 occur, or even a suppurative panophthalmitis. In the respiratory 

 tract secondary infection of the injured mucosa may lead to a 

 purulent bronchopneumonia. 



The internal organs in animals with mustard gas lesions of 

 the skin, eyes, respiratory or gastrointestinal tract offer nothing 

 of a specific pathologic nature. There is general congestion, 

 marked splanchnic congestion, acute catarrh of the intestines and, 

 in infected cases, some cloudy swelling of the kidneys. 



In fatal cases the cause of death is to be found in shock, 



