DISEASES OF THE OX AND SHEEP. 209 



If guinea-pigs or rabbits are inoculated subcutaneously, or fed 

 witbeitber human or bovine caseous tubercular matter, tuber- 

 culosis is produced; but there are differences which show that the 

 general tuberculosis which is produced in the case of human 

 tubercular matter being used is not exactly the same as that pro- 

 duced when bovine tubercular matter is employed. Rabbits readily 

 get bovine tuberculosis either by inoculation or by feeding, but 

 human tuberculosis, if communicated to them, takes a slower 

 course, and involves fewer organs, and even these are less 

 markedly affected. Fowls, on the other hand, cannot be so readily 

 inoculated with bovine tuberculosis as with human tuberculosis. 

 Dr. Klein and Mr. Lingard have proved that while fowls are 

 susceptible to tuberculosis as the result of feeding, and also 

 as a result of subcutaneous inoculation with human tubercular 

 matter, they appear to be much less susceptible to bovine 

 tubercular matter, in whatever way it may be introduced into 

 the system. Fowls may become infected with tuberculosis by 

 taking food contaminated with human tubercular sputum. 



It is very noteworthy that fowls infected with human tuber- 

 cular matter were extremely well nourished, although having 

 tubercular deposits. In the market they would have been 

 considered " very fine."" Moreover, guinea-pigs and rabbits are 

 affected differently by the two diseases, human tuberculosis and 

 bovine tuberculosis respectively. Guinea-pigs fed with bovine 

 tubercular matter develop tuberculosis more quickly, and with 

 wider implication of the viscera than guinea-pigs fed with human 

 tubercle. Two guinea-pigs fed with the tubercular liver of a 

 fowl became affected with tuberculosis, but the disease was of a 

 mild character. It is possible, therefore, that by passage through 

 the fowl human tubercular virus might be so attenuated as to 

 admit of the idea that it might be used successfully for purposes 

 of protective inoculation. 



At least two most interesting and important points seem to 

 have been elicited by the experiments of Dr. Klein and Mr. 

 Lingard. One is that the tuberculosis of fowls is more of the 

 nature of human tuberculosis than of bovine tuberculosis. The 

 other is that human tubercular matter, used to produce disease 

 in fowls, may undergo some loss of its infective power during 

 its passage through the fowl. Dr. Cash has found that a 

 restraining influence is exerted by ozone upon human and 



14 



