460 THE HEMORRHAGIC DIATHESES 



in a number of cases of purpura, as is evident from later investigations, the 

 proof of bacillary disease has been shown. Bacilli were found by Klebs, Ceci, 

 Reher, Demme, Vessalle, Gendre, Ginnard, Simon-Legrain, Jones, Tizzoni, 

 Giovannini, Kolb-Petrone, Babes and Letzerich; Hanot and Luzet, Widal and 

 Therese found streptococci; Lebreton and I each found staphylococci in one 

 case; negative findings on the other hand have been mentioned by Marfan, 

 Legendre, Demys and others. 



The opinion, especially maintained iy Petrone, that purpura hemorrhagica 

 in an infectious disease, Letzerich believes he has proven to be correct by bac- 

 teriologic investigation. In the case of a woman, aged twenty-five, who suf- 

 fered from a prolonged attack of this disease, who was, however, cured, he 

 found, in 1884, small, glistening, round granules in the blood. By culture 

 these proved to be the spores of a bacillus which he described and depicted 

 minutely as bacillus purpurse. With several generations of this culture a large 

 number of rabbits were infected by injection into the abdominal cavity, and 

 always with a positive result; the animals showed a short time afterward, 

 especially in the ears, circumscribed dilatation of the capillaries with succeed- 

 ing hemorrhage, injection of the gums, etc. ; if the animals were killed, sim- 

 ilar hemorrhages and vascular dilatations were found in various portions of 

 the body. The microscopic investigation showed in the blood-vessels in many 

 areas the previously described bacilli, that is, their spores. These were found 

 most constantly, and were most numerous in the enlarged liver. 



Letzerich in this connection points to the frequent enlargement of the 

 liver in the human affection. This is not to be construed as a frequent occur- 

 rence, however; in the organs of the experimental animals he found very 

 marked accumulations of erythrocytes, and stasis in the capillaries due to this. 

 Further, in the areas of the dichotomous branching of the smallest vessels hya- 

 line plugs developed by the action of the chemical poison produced by the 

 bacteria upon the albumin of the blood. To these vascular plugs he refers 

 on the one hand the hemorrhages into the organs, and on the other hand the 

 decided circulatory disturbance. The bacillus enters the human body, prob- 

 ably through the mucous membrane of the oral and pharyngeal cavities. 



Letzerich believes these investigations demonstrate with certainty that pur- 

 pura hemorrhagica is a chronic infectious disease, and points to its analogy 

 with syphilis and malaria. It is noteworthy that three years after these pri- 

 mary researches, and, as he states, in consequence of them, Letzerich himself 

 was attacked by a very prolonged purpura, running its course with marked 

 enlargement of the liver, and from his blood the previously described bacillus 

 was cultivated. 



The bacillus described by Letzerich has some similarity to the bacillus 

 anthracis, particularly in regard to the conditions of its growth. In Koch's 

 stab cultures both formed more or less irregular colonies (flocculi), the middle 

 point consisting of net-like threads which, toward the border, ran ofE in sheath- 

 like bundles. They differ decidedly, however, by their size and the form of 

 the spores. Although in both bacilli a segmentation of the apparent threads 

 occurs in various lengths, those of purpura are much smaller in their length 

 and breadth. Added to this the spores of Letzerich's bacillus, in comparison 



