554 
REPORTS ON THE INFLUENZA 
change in the thermometer of from 32 to 65, or even 70 degrees, 
o ' O 7 
in twenty-four hours. 
There can be no doubt entertained of the disease being in- 
fectious, but apparently so only through actual contact with the 
morbid secretion, which seems to be of an exceedingly virulent 
quality. 
From experiments and observations, it is found that the intro- 
duction of this morbid matter, from the nostrils of a diseased 
sheep, to those of a sound one produces the disease in the latter ; 
whilst an infected flock brought alongside of, but not in actual 
contact with a sound one, will not communicate it to them. 
The progress of the disease certainly led, in the first instance, 
to the belief that the infection was conveyed through the air from 
one flock to another; but, from the above facts, this could not 
have been the case. All attacked were, no doubt, affected 
through the same prevailing atmospheric contagion ; or in some 
particular instances, perhaps, from coming into direct contact 
with the morbid secretion dropped on the herbage from the in- 
fected flocks near them. 
The predisposing causes are supposed to be various, as feed- 
ing or unsound runs, costiveness from eating dry, hard hay ; 
drinking stagnant w^ater, or water impregnated with tannin ; 
and sudden removal from a warm or temperate to a cold run. 
Some few of these causes may, no doubt, have their predis- 
posing influence to a certain extent ; but none of them can be 
admitted as satisfactory reasons to account for the very partial 
attacks of the epidemic upon the numerous flocks exposed to it. 
The very remarkable manner in which it singled out the flocks 
of particular settlers for its victims, and passed over many others 
depasturing on the same or on contiguous runs, possessing similar 
qualities of soil and water, induces the belief that some special 
predisposing cause exists in the constitutions of those so particu- 
larly attacked ; and although it may be difficult to obtain impar- 
tial evidence on this point from all, enough has been elicited, 
from inquiry into the system of breeding pursued by many, to 
prove that constitutional deterioration, from too close breeding, 
or breeding in-and-in as it is termed, had been induced ; and that 
this has been the main predisposing cause, if not generally, at 
least in all the flocks wdiich have suffered the greatest mortality 
under the disease. 
Whether this or any other cause be admitted ultimately as the 
predisposing one, it is at present important to know, that the 
heaviest losses occurred among sheep thus closely bred, and at 
least for a period of six or seven years, without the interven- 
tion of any fresh blood ; and, what is still worse, without re- 
