Royal Veterinary College. 
113 
diagnosis “ Not anthrax ” may be made with almost absolute cer- 
tainty, even although the circumstances in which the animal has 
died have created a suspicion of that disease. 
Source of Infection in Anthrax . — The anthrax germ in certain 
circumstances is capable of multiplying and producing spores in 
soil or water, and when once such spores have been formed they 
may lie dormant for many years, and at the end of that time cause 
anthrax by being taken into the system of an animal with food or 
drink. Such multiplication and spore-formation can only take 
place when the bacilli are freely exposed to the air, at a temperature 
over 60° Fahr., and in the absence of putrefactive bacteria. It would 
be a perfectly hopeless search to endeavour by microscopic examina- 
tion to discover the particular spot of ground on which the cattle 
have picked up the germs of anthrax in any given outbreak, and this 
fact deserves to be brought home to stock-owners. In the vast 
majority of cases the most searching investigation fails to discover the 
exact source of the outbreak, and to declare one’s inability to point 
out the contaminated spot is no confession of ignorance or incom- 
petence. Occasionally the owner of an animal that has died from 
anthrax thinks otherwise, and the veterinary surgeon, to maintain 
his credit, is constrained to lay the blame on some particular article 
of the animal’s diet. 
Within recent years oil-cake and cotton-cake have frequently 
been thus accused. The notion appears to have arisen from a habit 
of reasoning loosely and jumping to conclusions. Generally the 
only evidence cited in support of it is that in such-and-such an out- 
break of anthrax the cattle were receiving cake, and if it can be 
added that no more deaths occurred after the cake was stopped the 
case is supposed to be proved beyond a doubt. In reality, however, 
this is no proof that cake is ever the means of infecting cattle with 
anthrax ; it would be evidence in that direction if it were not the 
case that more outbreaks occur among animals not receiving cake, 
and that in the great majority of cases the outbreak ends with the 
death of the second or third animal, even when no change is made 
in the diet. 
When cake is the cause of anthrax there is an obvious way of 
putting the fact in evidence, and that is to communicate the disease 
by feeding or inoculating experimental animals with it. On two 
occasions during the past year this test was applied to cake sus- 
pected of having caused anthrax. In the first of these cases the 
evidence — if such it can be called — pointing to the cake being at 
fault was unusually strong, and it therefore appears desirable to 
narrate the circumstances in detail. In the month of September 
last portions of two spleens, in which microscopic examination 
showed numerous anthrax bacilli, were sent to the Research Labora- 
tory, with the following history. One portion of spleen belonged to 
a bullock that had been grazing out of doors all the summer, and 
which had likewise been fed with a compound cake that was taken to 
the field daily by a cattleman. The other piece of spleen was taken 
from a heifer that had been confined to the byre during the pre- 
VOL. V. T. S. — 17 I 
