ON THE DISTEMPER AMONG CATTLE. 
649 
ham, Hecker, and so lucidly dilated upon by Professor Sewell, 
has been ridiculed by some writers, yet it seems highly probable. 
The diversity of character exhibited by these occasional diseases, 
I fancy, almost demonstrates the truth of this theory. Each miasm, 
on being introduced into the animal system under certain circum- 
stances, produces a certain train of phenomena* according to its 
kind. Some act on the blood and some on the serous or mucous 
membranes. Modern pathologists have revived the doctrine of the 
ancients, that their mode of action much resembles that of a fer- 
ment ; and, consequently, have included under the order zymoses 
(from zymoo, to ferment) all those diseases here alluded to, and 
formerly known as epidemics) epizootics, &c. By the introduction 
of this term into our nosology, and by restricting the use of the 
words infection and contagion to their literal signification, much 
ambiguity may be avoided. 
When the malaria or poison is reproduced in the course of the 
disease, and is capable of extending its action to another subject 
through the medium of the atmosphere, it is infectious ; but if, on 
being reproduced, contact with the sick or its secretions is neces- 
sary to its extension, then it is contagious. Every infectious dis- 
ease is contagious ; but the reverse does not hold. 
The distemper among cattle, the immediate subject of this paper, 
appeared in Ireland in 1841 and spread itself in that country, and 
at length gained the western coast of England and the northern one 
of Scotland. In August 1842, a farmer on an open plain near the 
centre of the maritime county of Cumberland bought four Irish 
stirks. In October one of these became ill ; he bled it and gave 
salts, but it died. 
Soon after another of the lot was in like manner affected. The 
same means were resorted to but without success, and, after some 
days, my attendance was requested. 
On comparing the history of these two cases, and the symptoms 
presented by the latter — which was evidently fast sinking — with the 
description of the new distemper generously presented to the pub- 
lic through the medium of The Veterinarian, by Mr. J. Barlow, 
I had little doubt of the identity, and intimated my opinion to the 
owner. The illness next shewed itself in two of his milch-cows, 
in the latter part of December, and for two months afterwards 
fresh cases continued to occur in this stock. 
It is worthy of remark, that the cattle which I have attended in 
this complaint were scattered over an area of twenty miles in 
diameter, and embraced almost every quality of location : but it 
was most fatal in a stock on the banks of the river Caldew, near 
* Vide Sewell’s Oration, Veterinarian, 1839. 
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VOL. XVII. 
