ON CHOLERA IN DOMESTICATED ANIMALS. 
225 
uuicous membrane in herbivorous animals is more liable to this 
affection than that of the omnivorous, and also why the disease 
prevails so much amongst them at the present time. To the first 
question I am inclined to answer, that vegetable food is more 
difficult of digestion than animal matter; and that this is proved 
by the greater length of time required, and the more compli¬ 
cated digestive apparatus with which these animals are provided 
for the purpose :—that vegetable food presents a greater variety, in 
regard to its nutritive properties, and is more liable to be acted on 
by external causes than animal food, and consequently, presented 
in a greater variety of states to the digestive organs, is more apt 
to undergo chemical changes in the viscera, producing decom¬ 
position and generation of gasses in the intestines. It is also 
more liable to produce mechanical irritation than animal food. 
To the second question, it is by no means easy to give so 
plausible a reply. It will, however, appear, that if there is at 
present an analogous disease prevailing both in man and animals, 
and that that disease has a peculiar character, the natural 
inference must be, that the same causes which operate in the one 
must be also exerting their influence on the other. That such 
is the case, I cannot omit to illustrate, even after all that has 
already been offered; because on Saturday last, the 10th inst. 
(after the occurrence of disease of the bowels had in a great 
measure subsided for two weeks) no less than five cases of 
this kind happened in my practice, one of which was, per¬ 
haps, as well marked with the symptoms of what I have sup¬ 
posed to be cholera, as any that has yet come under ray notice; 
and of these, this week has produced also a large proportion of 
cases. This recurrence of cases, be it remarked, has been si¬ 
multaneous with the increase or recurrence of cholera in the 
human being in the immediate neighbourhood—the Water of 
Leith ; and what is also as remarkable, that although that increase 
was for several days followed by a number of cases, they have 
gradually diminished in frequency, and during three days I 
have not had a case. 
What the cause or causes are, I am unable to explain ; but 
if, in addition to what I have already offered, as indicating a 
long continuance of a peculiar atmospherical influence, we con¬ 
sider the general state of the weather and atmosphere for these 
tw'O seasons past; the extraordinary brilliancy and frequency of the 
aurora borealis ; and also the following facts, that, during the pre¬ 
valence of the disease of the mucous membrane of the respiratoiy 
organs in the horse, it was observed by Mr. Stevenson, of Red- 
side, near North Berwick, whose horses were almost all affected, 
that, as he states in a letter to me, dated 6th May, 1831, it 
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