398 BACTERIA IN INFECTIOUS DISEASES. 



the tubercular material, and consequently could 

 not be isolated from it. 



If these experiments do not give strong support 

 to the view that the bacillus bears a causal relation 

 to the disease, they are at least not entirely 

 opposed to this view ; and it must be admitted that 

 they can be accorded but little weight as opposed 

 to the uniformly positive results reported by Koch 

 in a large number of inoculation experiments, and 

 the strong confirmation which he has received 

 from Cheyne, a very competent witness in a case 

 of this kind. 



This author paid a visit to Toussaint and to 

 Koch for the purpose of making himself familiar 

 with their methods. Upon his return to England, 

 a series of experiments was made, with the results 

 reported below. 



The experiments were made under the most 

 favorable hygienic conditions, and all possible pre- 

 cautions were taken as regards disinfection of 

 instruments and the complete isolation of the ani- 

 mals used. Twenty-five animals, inoculated with 

 non-tubercular material in various ways, failed to 

 become tuberculous. In six of these, setons were 

 introduced subcutaneously ; in ten, vaccine lymph 

 was employed ; in three, pyoomic pus was injected ; 

 and in six, various materials were introduced into 

 the abdominal cavity (cork, tubercle hardened in 

 alcohol, worsted thread). Cheyne believes that 

 in similar experiments made by other observers, in 

 which a positive result has been reported, the 



