468 
Abortion in Cows. 
as she had the previous season suffered from it. Neither can 
one attack of this malady, as is the case frequently in infectious 
diseases, act as a prophylactic against its recurrence, we having 
so many instances of animals aborting a second time. So 
much more likely are cows considered to again abort after once 
being so affected, that it is the rule (with exceptions) in this 
district not to attempt to breed from them. 
4. " Isolation promptly effected would stamp it out." Isola- 
tion was tried in pretty nearly every outbreak at its commence- 
ment ; in some by sending the affected animals away either 
before or immediately after the occurrence ; in others by 
keeping them in a separate shed in which gas-lime was some- 
times thickly spread on the floor. In all with the result that, 
however it was carried out, its beneficial effects could not be 
perceived. 
5. " That affected animals, whilst grazing, would sometimes 
impart the malady to in-calvers in adjacent fields." Certainly 
we should expect an infectious disease to spread under such 
circumstances, but not one of the thirty attributed their out- 
break to such a source. I have knowledge of a few instances 
where animals were so placed without any deleterious result. 
Reference under this head may be made to Case 13. 
6. " That a change of hay or grass (all other circumstances, 
so far as known, remaining unchanged) would be ineffectual 
to arrest the malady." Nos. 1, 2, and 3 negative this rule 
with respect to hay. Nos. 7 and 3 tend to do the same with 
regard to grass. In the former, I refer to the six weeks' change 
from pasture to aftermath ; in the latter, to the intermission 
whilst the heifers were in the Ridge fields. No. 26 also bears 
on this point, as in 1882, finding the majority of his in-calvers 
aborting, he determined to try to clear his farm of infection by 
selling his remaining (nine) in-calvers. This he did to Mr. 
P. N., one of which aborted within three weeks of leaving, the 
remaining eight carried their calves the full period. 
7. " That animals known to have recently aborted would be 
capable of conveying the infection to others." I have no 
evidence that this malady has ever been so conveyed, though 
the opportunities of doing so were frequent, as two farmers who 
were heavy losers by this affection were largely dealing in 
milch-cattle during the time that their own herds were suffering 
heavily. Cows were generally purchased a few days or weeks 
prior to calving, and were sold a few days after the event. They 
frequently calved in close proximity to aborting animals, some- 
times in stands recently occupied by such. The animals which 
aborted, if they made fair bags, were sold in the usual course ; 
but the best were not fit for sale under ten days, and some for 
