BY THE HON. A. NORTON. 117 



tuberculous cow can infect man ; but we have direct and positive 

 evidence that, whereas the transmission of tuberculosis from 

 cattle to cattle produces only the ordinary bovine form of the 

 disease, and whereas inoculations of cow virus to a fowl (a most 

 susceptible subject), produce no tubercle, when cows are 

 inoculated with the human virus the disease is reproduced in its 

 acute form, and dogs and fowls which eat the sputum of a 

 phthisical patient are subjected to a sudden and acixte attack of 

 tuberculosis, although they were perfectly healthy until the con- 

 sumptive person came amongst them. With the more highly 

 organised human subject, the tubercular poison is most virulent ; 

 but in the inferior susceptible animals there is apparently a 

 tendency in the direction of diminished activity. Such being 

 the case, may we not reasonably believe that the inferior animals 

 are more in danger of the virulent poison of human tuberculosis 

 than human beings are of the modified — I had almost ventured 

 to say attenuated — poison of the inferior animals ? 



As for cattle, it is a fortunate thing for them and their owners 

 that the opportunities of infection by means of the sputum of 

 phthisical patients are not so frequent as is the case with fowls 

 and dogs. We must not, however, lose sight of Fraenkel's opinion 

 already quoted as to the manner in which we men may contract 

 tuberculosis by inhaling the dried sputum of phthisical persons. 

 If, as he says, this " will be found a source of infection flowing, 

 unformnately, so copiously that other sources need hardly be 

 looked for," how can our cattle escape the danger ? These 

 copious expectorations are not, by any means, limited to houses 

 and streets, nor even to railway smoking carriages, and carriages 

 that are not reserved for that purpose ; they are distributed as 

 freely and as heedlessly over the pastures where cattle are kept, 

 and the unfortunate animals can scarcely avoid the bacilli when 

 these are there ; for the life of an ejected bacillus is not limited 

 to a few hours or days. In France and Germany, Woodhead 

 tells us, observers " very eai*ly pointed out that putrefaction and 

 drying could exert but little influence on the number of the 

 bacilli ; whilst drying alone interfered only slightly with their 

 virulence, as it was quite easy to inoculate rabbits with sputum that 

 had been dried at a temperature of 30 degs. C. Later, Galtier 

 found that maceration and putrefaction for a period of five days,. 



