ON THE DISEASES OF FA EM HORSES. 345 
it becoming effete and taken away, whilst new parts are endowed 
with the property of life, and are built up in their places. The 
living principle is permanent, whilst the material changes, and 
the reparatory process cannot be maintained in its integrity unless 
the body be supplied with food adequate to its peculiar wants. 
This should contain a large supply of the phosphates, from which 
bone is formed, and of gluten, or fibrine, by which the muscles 
are enlarged. These materials are obtained from corn, bran, 
beans, natural and artificial grasses, and roots of various kinds. 
In the absence of materials of this kind, the bones do not increase 
in size, and the muscles are not sufficiently developed, and hence 
the common origin of so many ill-shaped, long-legged, light- 
carcassed horses, that are almost always sold at inferior prices, 
and frequently to persons who do not scruple to use them quickly 
up in work beyond their age and strength. 
Hitherto we have considered the immediate operation of wet 
and cold arising from insufficient shelter, together with insuffi¬ 
cient food in the rearing of colts. We will now trace these in¬ 
fluences on older horses. 
In some counties, the farmers’ working horses are kept at 
grass from the month of May to the latter part of October, ex¬ 
cepting during the hours of labour, or the short interval occur¬ 
ring in the mid-day meal, when cut grass, vetches, hay, or a 
small allowance of corn may be afforded them. To say nothing 
of this objectionable practice, as far as the loss of manure, in¬ 
jury to the pastures, and great expenditure of labour on the part 
of the horse in procuring food, it is highly injurious in other 
respects. The sudden transitions experienced between the ex¬ 
citing state of labour by day, and the cold and wet occasionally 
at night, weakens the circulation of the surfaces of the body, 
and the blood accumulating more in the internal parts, produces 
congestions, and hence inflammation of the mucous membranes 
of the air passages, causing catarrhal complaints, such as coughs, 
sore throats, bronchitis, besides their common consequences, as 
chronic cough, thick wind, and sometimes broken wind. 
Fluxes of the bowels are also occasionally produced in this 
manner, from grazing on marshy pastures during the cold au¬ 
tumnal nights. Idiopathic tetanus is also produced in horses 
from exposure to the cold mists, fogs, and hoar frosts which 
prevail during the autumn, and this more commonly occurs 
when they are kept in marshes and unclaimed lands bordering 
on the sea. 
I should observe, that these tetanic diseases frequently occur 
during the moulting season—a process that always produces a 
great expenditure of vital power in horses; and in this state 
VOL. XXV. 3 A 
