sio Mr. Brodie's Observations and Experiments 
wound in a dog, the animal died in twenty-fours, and the 
stomach was found to be considerably inflamed. 
I repeated this experiment several times, taking the pre- 
caution always of applying a bandage to prevent the animal 
licking the wound. The result was, that the inflammation of 
the stomach was commonly more violent and more immediate, 
than when the poison was administered internally, and that 
it preceded any appearance of inflammation of the wound.'* 
Some experiments are already before the public, which led 
me to conclude that vegetable poisons, when applied to 
wounded surfaces, affect the system by passing into the cir- 
culation through the divided veins. From this analogy, and 
from all the circumstances just mentioned, it may be inferred 
that arsenic, in whatever way it is administered, does not pro- 
duce its effects even on the stomach until it is carried into the 
blood. 
But the blood is not necessary to life, except so far as a 
constant supply of it is necessary for the maintenance of the 
functions of the vital organs. The next object of inquiry 
therefore is, when arsenic has entered the circulation, on what 
organs does it operate, so as to occasion death ? 
When arsenic is applied to an ulcerated surface, it produces 
a slough, not by acting chemical!}^ like caustics in general, 
but by destroying the vitality of the part to which it is applied, 
* Since the greater part of my experiments on this subject were made, I have seen 
an account of an inaugural Dissertation on the Effects of Arsenic, by Dr. Jacger. of 
Stuttgard. Dr. Jaeger has come to conclusions similar to those above stated, that 
in an animal killed by arsenic, the inflammation of the stomach is not the cause of 
death, and that the poison does not produce its fatal effects until it has entered the 
circulation. I have to regret that I have had no opportunity of seeing the original 
of this Dissertation, 
