550 
REPORTS ON THE INFLUENZA 
be classed among the predisposing causes. But some diseases 
are capable of being propagated, and the external cause can be 
demonstrated in a specific virus, capable of producing that dis- 
tinct and peculiar affection. Thus smallpox, syphilis, 8cc., may. 
be kept up and disseminated by their own original principle. 
If the state and variability of the atmosphere was more studied 
during the visit and previous to the appearance of epidemical 
diseases, there would be much light thrown upon that cause, 
which is at the present day so readily assigned to contagion ; 
indeed, we find the idiosyncrasy of different individuals such, 
that during the time the wind blows from a certain quarter, they 
feel indisposed, without any other assignable reason ; and if 
wounded, the w'ound will not heal from the same cause : that 
others, again, suffer violent headachs when the atmosphere is 
charged with abundance of electric fluid, and which subside when 
that peculiar state of weather has passed. 
Although I look upon a peculiar state of atmosphere as the 
immediate cause of this epidemical disease, yet the predisposing 
cause among sheep may have originated in — first, breeding ewes 
twice in a season; second, the injurious effects which result 
from breeding in the same flocks, or what is technically termed, 
“ breeding in-and-in,” by which, although the quality of the wool 
may be improved, the constitution of the sheep is so weakened 
as to render them liable to disease, and susceptible of the atmo- 
spherical changes ; and, third, the constitution of the sheep 
having been injured by mercurial remedies used in scab, as well 
as from the effects of that eruptive disease itself. 
When engaged in the present investigation, a query arose, 
whether fine woolled sheep were more apt to suffer from the pre- 
sent epidemic than coarse woolled sheep ; and I found that 
the finer woolled sheep had suffered severely, while the coarser 
woolled sheep had escaped entirely, or very slightly, except Mr. 
H. Hume’s flock, which consisted of second class sheep ; but 
then they w r ere nearly all aged ewes. 
The vicissitudes of the climate in this colony are found to be 
very great. I have often remarked that the mornings during 
the summer season are intensely hot, followed frequently during 
the afternoons and evenings by cold chilly winds, the tempera- 
ture varying from 10° to 20° : it is therefore not uncommon for 
men working in the fields during harvest, nearly stripped of 
their clothing, when the sudden change of temperature takes 
place, to be attacked by head-achs, pains in the limbs, and ge- 
neral debility, frequently followed by catarrh. In Captain 
Rossi’s flock, I am inclined to attribute one of the causes of the 
epidemic to change of locality, from a mild to a severe climate. 
