168 ON THE INFLAMMATORY FEVER OF CATTLE. 
dissections we find the veins considerably turgid, and the arteries 
empty. The last act of life is to propel the blood from the ar¬ 
teries into the veins. But the strangely increased turgidity of 
the venous system, even in its minutest ramifications in this 
disease, undeniably indicates the previous intensity of arterial 
action. In consequence of the increased force of arterial power, 
more blood is driven into the .vessels of the cranium. The ar¬ 
teries are distended in consequence of the increase of fluid which 
they carry. They press upon the substance of the brain; that 
pressure is communicated to the veins; the circulation through 
that important organ is impeded; hence the stupor and insensi¬ 
bility, and staggering and debility, which mark the earliest period 
of the malady; and hence the rapidity with which the natural 
powers are exhausted, or the fever assumes a putrid type. 
The nervous energy being thus impeded, the powers of locomo¬ 
tion seem first to fail; rapid debility ensues; and then the vas¬ 
cular system begins to suffer. The mouths of the excretory ducts 
are no longer able to contract on their contents; hence the fluids 
effused in the thoracic and abdominal cavities; hence the fluid 
effused in the cellular membrane, and the rapid formation of ulcers. 
The vital powers generally are weakened; hence the speedy ten¬ 
dency of every excretion to putridity, and the actual commence¬ 
ment of decomposition even in the living animal. The emphysema 
of the cellular membrane is produced by the extrication of gas, in 
the incipient process of putrefaction and decomposition. The 
blood shares in this abstraction or deficiency of vitality, and tc 
this, perhaps, more than to any thing else, is to be traced the dis¬ 
position to ulceration, gangrene, and dissolution, by which the! 
latter stages of the disease are characterised. 
Comparing bulk with bulk, the heart of the bullock is of largei 
size, and parietes of the arteries thicker and stronger, than in the 
horse; and hence the greater tendency to inflammatory fever, and 
the more rapid course of it, than in the horse. The horse is like¬ 
wise subject to greater alternations of heat and cold; to a more 
artificial and unnatural treatment; and hence the tendency to loca 
rather than to general inflammation.—The beasts most exposec 
to attacks of inflammatory fever are those in high condition, oj 
who have been rapidly improving in condition. It oftener occurs ii 
oxen, and in cows that have been dried for fattening, than in mild 
cows. Calves are very rarely the subjects of it. 
Causes. —It has been said, how truly I know not, that tin 
malady has very materially increased since the introduction o 
artificial grasses. We have no records of the diseases of cattk 
on which sufficient dependance can be placed. We do, however 
know, that it is a disorder almost peculiar to beasts in high con- 
