6 4 
E. P. NILES. 
stationary, and estimating their value at $15 per head, the total 
value is $6,104,055. If 2% of these cattle are tuberculous, we 
then have 8,138 tuberculous cattle in Virginia. These cattle in 
health represent $122,070. Each one of these diseased cattle 
is capable of communicating the disease to one or more healthy 
individuals ; in fact, one animal may affect a whole herd. But 
suppose the infection is in the ratio of one to two of every dis¬ 
eased animal each year. We will suppose then that in the year 
1894 we have in Virginia 8,138 animals; at the above ratio of 
infection we will have in 1895, 10,350 tuberculous animals; in 
1896 we will have 14,466. It will be seen that the number of 
tuberculous animals is rapidly on the increase, even with this 
small ratio of infection. If the true ratio of infection could be 
gotten at, however, I am of the opinion that it would be much 
greater. What other disease can produce such appalling fig¬ 
ures ? The infection does not stop with animals of the same 
species, but may extend to nearly all warm-blooded animals, 
and especially to the human family. I have stated in a previous 
article that fifty per cent, of the cases of tuberculosis in the 
human family came from the bovine species. If one person 
for every ten tuberculous cattle becomes infected from that 
source each year, we will have 813 more cases of tuberculosis 
in the human family in 1895 than in the year previous, and 
1,085 * n 1895, and so on year after year, to say nothing of the 
spread of the disease by those so infected. 
Let us see what would be saved to the State and the private 
stock owners each year by stamping out the disease. 
Let us suppose that one-half of the tuberculous animals are 
destroyed at once. We would have left but 4,969 diseased ani¬ 
mals to spread the disease. The number infected by these, 
according to the above ratio, would be 1,356, making a total 
number of 5,425 affected animals in 1895, as compared with 
10,850. In 1895 we will slaughter the remaining half of the 
original number, thus reducing the number of diseased animals 
to 1,356. In 1896 the infection will thereby be reduced to 452 
animals, so that in the third year of our work we will have but 
