310 ANTHRAX. 



and usually is seen among those whose trade leads them to 

 handle the carcases or skins of animals which have died of the 

 disease. It occurs in two principal forms, the main difference 

 between which is the site of entrance of the organism into the 

 l)ody. In one, the path of entrance is through cuts or abrasions 

 in the skin, or through the hair follicles. A local condition 

 •called a " malignant pustule " develops, which may lead to a 

 general infection. This variety occurs chiefly among butchers 

 and those who work among hides (foreign ones especially). In 

 Britain the workers of the latter class chiefly liable are the hide- 

 porters and hide-workers in South-eastern London. In the 

 •other variety of the disease the site of infection is the trachea 

 and bronchi, and here a fatal result almost always follows. The 

 cause is the inhalation of dust or threads from wool, hair, or 

 bristles, which have been taken from animals dead of the 

 disease, and which have been contaminated with blood or secre- 

 tions containing the bacilli, these having afterwards formed 

 spores. This variety is often referred to as " woolsorter's dis- 

 ease," from its occurring in the centres of the woolstapling trade 

 (in England, chiefly in Yorkshire), but it also is found in places 

 where there are hair and brush factories. 



( I ) Malignant Pustule. — This usually occurs on the exposed 

 surfaces, — the face, hands, forearms, and back, the last being a 

 common site among hide-porters. One to three days after inoc- 

 ulation a small red painful pimple appears, soon becoming a 

 vesicle, which may contain clear or blood-stained fluid, and is 

 rapidly surrounded by an area of intense congestion. Central 

 necrosis occurs and leads to the malignant pustule proper, 

 which in its typical form appears as a black eschar often sur- 

 rounded by a ring of vesicles, these in turn being surrounded 

 by a congested area. From this pustule as a centre subcutaneous 

 oedema spreads, especially in the direction of the lymphatics ; 

 the neighbouring glands are enlarged. There is fever with 

 general malaise. On microscopic section of the typical pustule, 

 the central eschar is noticed to be composed of necrosed tissue 

 and degenerating blood cells ; the vesicles are formed by the 

 raising of the stratum corneum from the rete Malpighi. Be- 

 neath them and in their neighbourhood the cells of the latter 

 are swollen and oedematous, the papillae being enlarged and 

 flattened out and infiltrated with inflammatory exudation, which 



