768 MIDLAND COUNTIES VETERINARY MEDICAL ASSOCIATION. 
infectious enzootic, and the farm, the locality, the atmosphere, the 
vegetation, the water, artificial food and manures, and other innocent 
agents were improperly credited with the evil. 
Causes . — The conclusion that has been arrived at by various 
learned commissions, and the individual investigations of several 
distinguished gentlemen in our profession, is that the disease 
was unknown in England (during this century) prior to the year 
1841, and that since its appearance, the markets, fairs, and farms of 
cattle dealers have constituted the busy centres of infection ; that 
the late cattle plague restrictions have partially obliterated it, and 
the recent parliamentary enactments taken as a public expression 
regarding it, together prove its contagious character. But in none 
of these elucidations have the method of propagation or the probable 
period of its communication from a diseased animal been suggested. 
Hence the absurd “regulations” that permit owners of infected 
herds to dispose of them without restraint thirty days after the last 
recognised attack. 
The method of its propagation would appear to be difficult to 
make out, as inoculation of healthy animals with what we deem to 
be the actual virus fails to produce any effects identical with the 
affection taken naturally ; and chemistry tells us that in the structure 
and chemical constitution of the various animal poisons there is no 
difference, that they may be either fluid or volatile, and that often 
the most potent ones are simple fluids, and that we know them only 
by their effects. But the period of communication would seem to 
be more within the region of our observation. 
In giving my local experience, I should say it never arose spon- 
taneously, and never spread but by contagion, however mysterious 
the history of its occurrence may appear to be when we are fur- 
nished with the whole truth. I have of late years seldom failed 
to trace its origin ; thus I have ascertained that atmospheric influences 
and other abnormal agencies were only accessory causes, tending to 
increase or mitigate the severity of the disease, not to induce it. 
It may, however, be observed that parturition, lactation, and in- 
sufficient food exhausting the vital energies, render milch cows and 
cow store stock particularly liable to its ravages. 
With your permission, Mr. President and Gentlemen, I will now 
give you the history of a few cases illustrative of my position. In 
the month of May, 1865, a farmer and cattle dealer in my neighbour- 
hood bought three cows in Yorkshire ; one he sold to his landlord, 
a magistrate, the second to a neighbouring farmer, and the third he 
concluded to keep. The last was, therefore, turned with his herd 
of twenty milking cows. In a fortnight after this animal had been 
so pastured, I was requested to see her. On my second visit I was 
of opinion the animal was affected with contagious pleuro-pneu- 
monia, and ordered her to be slaughtered, as death seemed in- 
evitable. The owner desired me not to say a word-, as it would 
injure his transactions, not then telling me anything about her 
two fellows, which were sold and gone. No other case happened 
here. 
