REVIEW. 
446 
muscular contraction, I may say that almost every five 
minutes, and sometimes oftener, I took notes of the state of 
the animal; and did not note such words as spasm or effort , 
but avoided the danger of erring in judgment by describing 
in periphrases all I saw. It is important to notice that in 
the same animal, on a subsequent day, I injected 30 grains 
of tartar emetic in 1J oz. of water, without producing any 
sensible effect whatever. I injected 50 grains of tartar 
emetic, dissolved in 1J oz. of tepid water, into the jugular of 
a mule, with the following result:—Fourteen minutes after 
the injection, the animal did not present any change; but, 
in a few minutes more, left off eating and stood still. In 
the ensuing thirty-seven minutes, the muscular system was 
several times subject to momentary rigidity, which, with the 
exception of slight elevation and extension of the head, was 
unaccompanied by any movement. This muscular rigidity 
simulated the tetanic state, and contrasted strongly with the 
state of the muscles of the same animal while voiding faeces 
and urine; in an hour and fourteen minutes the mule 
resumed eating, and presented no other symptoms. If I 
had been a little less cautious in the avoidance of fallacy, it 
is very likely I should, in observing these muscular phe¬ 
nomena in two of the experiments, have succeeded in seeing 
attempts to vomit; but they assuredly were not such, for 
they did not in any degree resemble the efforts made by the 
same animals to evacuate the bladder and rectum, or the 
efforts made by the dog and man to empty the stomach 
through the oesophagus. 
Considering the vague manner in w r hich M. Dupuy alludes 
to his experiments, and, on the other hand, confident of the 
fairness with which my own have been conducted and 
recounted, I feel myself justified in opposing my conclusions 
to his, and in stating that all the attempts hitherto made to 
excite efforts to vomit in the horse by emetics have failed. 
This unsusceptibility to emetic action, and the very rare 
manifestation of the phenomena of vomiting by the horse, 
must obviously be regarded as cause and effect, and, con¬ 
sequently, as the answer to the question, Why does the horse 
rarely vomit ? 
February 7th, 1852. 
