TUBERCULOSIS. 397 



In the first edition of this work the writer gave 

 a summary of results obtained in his own experi- 

 ments, made soon after the announcement of Koch's 

 discovery. This has been omitted from the pres- 

 ent edition to make room for Plate IX, which is 

 an accurate reproduction of the selected figures, 

 copied from Vol. II. of the " Mittheilungen." 



In the experiments referred to, several rabbits 

 and two guinea-pigs were successfully inoculated 

 with tuberculous sputum, and an attempt was 

 made to cultivate the bacillus, but without success. 

 Failure was probably due to the fact that, not 

 having a supply of gas at the military post where 

 the experiments were conducted, it was found 

 impossible to regulate the temperature of the 

 culture-oven to as nice a point as appears to be 

 necessary. " In the animals successfully inocu- 

 lated the enlarged tuberculous lymphatic glands 

 in the vicinity of the point of inoculation, and 

 tubercle nodules in the lungs and elsewhere, usually 

 contained the bacillus of Koch. But this was not 

 invariably the case." The writer is at present 

 inclined to believe that a more protracted search 

 might have demonstrated their presence in every 

 case. Some recent experiments made in Balti- 

 more (not yet published), and a careful considera- 

 tion of the experimental evidence as given by 

 Koch in his elaborate memoir in the second volume 

 of the " Report of the Imperial Board of Health," 

 have removed the last remnant of scepticism from 

 the writer's mind ; and to-day he considers it 

 established that tuberculosis is an infectious dis- 



