WHY THE HORSE RARELY VOMITS. 
125 
of vomiting by the horse, must obviously B be regarded as 
cause and effect, and, consequently, as the answer to the 
question. Why does the horse rarely vomit ?’’ 
While discussing this question some months afterwards at 
Stuttgart, with the learned Hering, he made me acquainted 
with the results of experiments by Viborg, of Copenhagen, 
who was stated to have succeeded in producing efforts to 
vomit in horses, by the injection of tincture of white helle- 
bore into the jugular vein. Moreover, Professor Hering 
courteously offered to repeat the experiments in my presence 
in the veterinary school under his direction, an offer which 
I embraced with delight. In less than two minutes after 
injection of a drachm of the said tincture into the jugular, 
the horse became restless and covered with profuse sweat; 
viscid saliva flowed in large quantity, the pulse became 
small, the muscles of the neck spasmodically contracted, 
and those of the abdomen rigid ; the latter were, however, 
much less affected than the former. These symptoms gra- 
dually disappeared without the manifestation of any others, 
and in about an hour the horse had regained his pristine 
condition. The experiment was repeated with a similar 
result. 
The impression produced on my mind by the just-quoted 
experiments was, that the injection of white hellebore pro- 
duced greater and more speedy nausea, and more action of 
the cervical and abdominal muscles than I previously believed 
any agent could produce; and, while the phenomena of 
muscular contraction certainly did not amount to the violent 
muscular phenomena of the act of vomiting as witnessed in 
the dog and man, yet it was proved that the horse was not 
wholly unsusceptible of the nervous influence which is 
known to precede the act of vomiting ; and that once that 
influence had been produced, some very remarkable pheno- 
mena of muscular contraction ensued. Subsequent obser- 
vation and reflection has confirmed that impression, the 
result of which is an admission that when I stated in 1852 
that “ all the attempts previously made to excite efforts to 
vomit in the horse by emetics had failed,” I should have 
been nearer the truth had I been less general, and sub- 
stituted the name tartarized antimony for the generic expres- 
sion emetics . I at once communicated this criticism of my 
own opinion to Professors Ercolani and Vella, the secretaries 
to the Biological Society of Turin, before which learned body 
my first ‘ Inquiry’ had been discussed. After commenting 
in most generous and encouraging terms on my anxiety to 
discover the truth, those gentlemen made my communication 
