32 



firmed, after inoculation with isolated bacteria, by one 

 competent observer tuberculosis. 



Third. Diseases which are uniformly characterized, 

 intra vitam, by the presence of bacteria in the tissues ; 

 but which have not as yet been induced by inoculation 

 with the isolated bacteria recurrent fever, pyaemia, 

 diphtheria, erysipelas, leprosy, rhinoscleroma, gonor- 

 rhoea (urethras et conjunctivas), and some forms of septi- 

 caemia. Puerperal fever, osteomyelitis, and ulcerous 

 endocarditis are considered to belong etiologically with 

 pyaemia, septicaemia, erysipelas, and diphtheria. 



Fourth. Disease after death from which (in some 

 cases also during life) bacteria have been observed in the 

 tissues : variola, scarlatina, typhoid fever, croupous pneu- 

 monia. 



Fifth. Diseases in which the presence of bacteria, 

 ante or post mortem, has been asserted : syphilis, inter- 

 mittent fever, yellow fever, typhus, measles, lupus, rabies, 

 tetanus, et al. 



The investigation of the diseases included in the 

 fourth and fifth classes is as yet quite imperfect and in- 

 accurate, partly at least because they are with few excep- 

 tions peculiar to man. 



The evidence as to the relations of bacteria to disease 

 rests largely upon experimental observations upon the 

 lower animals. The impossibility of thorough examina- 

 tion of human tissues, not only during life, but also for 

 hours or days post-mortem, restricts materially the field 

 of clinical observation on this subject ; for a few days, 

 even hours, suffice to people a dead body with bacteria. 

 We may simply ignore such contributions as that of 

 Zander ( Virch. Arch., Ed. LIX.), in which he announced 

 the probable discovery of the bacterial origin of acute 

 yellow atrophy of the liver. In one fatal case of the 

 disease he found bacteria in the liver, the section hav- 

 ing been made fifty-four hours after death. He antici- 

 pates the possible objection that the bacterial develop- 

 ment was perhaps post-mortal, and refutes it with the con- 

 vincing statement that " the body did not, so to speak, 



