646 
LECTURE ON THE DISEASES OF CATTLE. 
in crowded situations, as well as in those which are not crowded — 
where there are great numbers of cattle as well as where there are 
but few. Still it must be remembered that circumstances may 
modify it. An animal which is kept alone may not have the dis- 
ease so virulently as others which are confined together in masses ; 
and it is certain that where animals are confined together in a small 
space, with impure air, there will the suffering be most severe. 
Wherever an animal, however, is in a predisponent state for dis- 
ease, we shall find that, if placed in contact with another animal 
previously suffering under it, that animal will be affected. Take 
a flock of sheep, or a herd of cattle, in a predisponent condition, 
and introduce among them other animals in a diseased condition, 
the disease will spread through them all at once, and you will have 
all the characteristics of contagious disease : whereas, if you place 
among them animals which are not in this condition, you will not 
find them suffering at all. 
Now, as regards the origin of the disease, it is thought by many 
that it travels in the atmosphere ; but how, in that case, it is gene- 
rated it is impossible to say. It may proceed from the effluvia arising 
from the animals themselves, or from electric disturbance. Another 
cause to be assigned is connected with the food of animals. During 
the period to which I have referred there had been a great deal of 
blight among the grasses, the clovers, and the sanfoins. There 
was a great deal of this food blue and blighted in appearance ; and 
though animals eat it, yet it must be remembered that they do not 
thrive upon it. This was the case, to my own knowledge. Im- 
pure food, in the early growth of animals, may have produced, or 
rather added, to the predisponent condition, while the effluvia 
arising from the animals, and other causes, bring that predisponent 
condition into a state of activity. 
Now the question arises — How is such disease as this to be 
met ] It must be met in two ways ; first, by the proper medical 
treatment, to supply the defects existing in the component parts of 
the body ; and, secondly, by general treatment and management. 
Upon the first point I cannot now enter, as I had intended, for 
reasons which have been already stated. It is, however, of great 
importance, I think, that we should enter upon the question of ge- 
neral management, or what is called “hygiene.” And here we 
find very important circumstances around us. We have animals 
placed in different positions, some of which are fed high and some 
low; and without now inquiring under what circumstances we 
shall find the greatest progress made towards the production of 
the largest animals from the smallest amount of food, it is sufficient 
to say that this is the question for general consideration. 
In making the remarks which I am about to do, I probably shall 
