336 
J. T. DUNCAN. 
efits of our own precautions in the matter. Our immunity from 
this plague is a source of gratification, especially to the veterinary 
profession, and if the Government, in concert with the profession, 
can preserve to the Dominion a continuance of that immunity, 
they will deserve the thanks of all. 
But we know not how long this condition may remain. Along 
our southern frontier lies an infected country. True, the west 
as yet claims exemption, but this fact has not been established by 
proper veterinary inspection. The inter-state trade is practically 
unchecked, and the only reason why the west is not affected is 
the fact of the course of the cattle trade being from west to east. 
Nor are we in danger of infection from the United States only, 
but from Great Britain as well. 
And other contagious diseases besides the one just mentioned 
demand our care and vigilance that they may not be brought into 
the country. To supply the information necessary to guard 
against such plagues, and to spread information regarding them 
in an available form, these pages have been written. The more 
important facts will be stated as concisely and as clearly as possi¬ 
ble, while practical matters, as distinguished from theoretical spec¬ 
ulations, will receive most attention. 
HISTORY. 
Although various writers have stated that this disease has ex¬ 
isted from time immemorial, no really good account of it w’as 
written till the eighteenth century. From the hazy and extremely 
general description of previous authors, it is difficult to make out 
of what affection they are writing. Some, however, have sup¬ 
posed that Virgil wrote of pleuro-pneumonia so long ago as 
before the birth of Christ, quoting, in support of that opinion, a 
description found in the third book of Georgies. During the 
eighteenth century it prevailed more or less extensively in Europe, 
and in 1769 Bourgelat, a French veterinary surgeon, first wrote a 
good description of it. Not, however, till 1842 was it brought to 
Great Britain, from which country it has never since been ban¬ 
ished. To the United States it “ was imported in 1843 and 1850 
