220 
FIFTH REPORT — 1835. 
reject from the stomach whatever offends it, induced me, after 
having unsuccessfully attempted to poison four of them with 
arsenic, to desist from making them the subject of experiment. 
It appeared desirable to employ an herbivorous as well as a car¬ 
nivorous animal, and for this purpose I selected the horse, as 
the most accessible animal of sufficient size; and though his 
stomach differs materially from that of man, I conceive that the 
choice has not been an useless one. 
Of the Modus Opercmdi of Poisons. 
This subject having been made the object of very careful in¬ 
quiry by my friends Dr. Addison and John Morgan, with the 
result of showing that the influence of poison depends rather on 
a power exerted through the medium of the nerves, or by sym¬ 
pathy, than on the contamination of the circulating fluids by 
absorption, I have not thought it necessary to direct my atten¬ 
tion to it in the experiments which I have made. There was 
one point, however, which appeared to me to be worthy of 
attention in reference to the modus operandi when the stomach 
is the organ acted upon by poisons, viz., Are the effects pro¬ 
duced to be attributed to the mere injury of the organ, connected 
as it is with the rest of the system by the most astonishing 
sympathy; or is the principal stress to be laid on the specific 
action of the poison ? The fact that a number of persons have 
been killed by drinking boiling water, who have died exhibiting 
manjr of the symptoms of poisoning, shows that the lesion of the 
stomach without specific influence is a very adequate cause of 
speedy death: still I w r as desirous of ascertaining the degree and 
extent of the mischief induced by this cause compared with 
what takes place when a poison is employed; I therefore had 
three ounces of water nearly at the boiling-point thrown by 
means of a syringe into the stomach of a small and young dog. 
It was almost instantly returned nearly as clear as when re¬ 
ceived, and still at a high temperature. After having thus re¬ 
jected the water, the dog exhibited so little symptoms of uneasi¬ 
ness that I almost suspected that little or no mischief had been 
inflicted; but in a short time he made efforts to vomit, and re¬ 
jected a clear fluid somewhat frothy and mixed with a little 
coagulated secretion resembling lymph or slightly heated albu¬ 
men ; he continued to repeat similar efforts at various intervals, 
the matter rejected bearing the same character as before, but 
occasionally tinged with blood. He appeared at times to suffer 
inconvenience in his throat, but his sufferings did not seem to 
be very severe; they appeared, however, to be on the increase 
