633 
EFFECTS OF CHLOROFORM ON ANIMALS. 
so much, indeed, that it beats with less frequency and force than in 
health at the moment of the extinction of sensibility. This last 
result obtained, the muscular system becomes relaxed, and mobi- 
lity, more or less, completely suspended. 
These constitute the general phenomena invariably present on 
such occasions. But I felt desirous of knowing what was the con- 
dition of the arterial blood during chloroform inhalations, and espe- 
cially at the moment when anaesthesia was produced. 
These experiments consisted in rendering dogs insensible by 
chloroform inhalation, and then drawing blood from arteries already 
laid bare for the purpose. The blood which immediately followed 
the puncture of the artery invariably proved of a dark venous or 
brownish hue, but as invariably speedily turned florid red on the 
animal being suffered to respire the common air again. 
After having convinced myself, by these experiments, of the in- 
variability of the blood to grow dark-coloured under the influence 
of chloroform, the same as under etherization, I became anxious 
to ascertain whether such a result was to be attributed to a specific 
action of the anaesthetic agent on the lungs, or simply to the rare- 
faction of the respired air caused by the admixture with it of 
chloroform gas. For this purpose, I induced insensibility by in- 
jecting chloroform into the veins, as completely as though I had 
administered its vapours by inhalation, and the moment insensi- 
bility was produced drew blood as before from an artery previously 
laid bare. Now, however, the stream of blood exhibited a florid 
red hue. 
This last experiment proved to me that it was not by any action 
on the globules of the blood that either chloroform or ether caused 
a change in their colour ; but by occupying the place of a suffi- 
ciency of common air, and thus more or less completely interfering 
with sanguification in the lungs. 
I do not, however, infer from this that suspension of sensibility 
and mobility from ethereal or chloroform inhalations is the result 
of defective sanguification or asphyxia, or that the latter neces- 
sarily accompanies ansesthesia. On the contrary, 1 have reason 
for believing that this last principally depends upon the special 
soporific action of the ether or chloroform on the nervous system, 
without any previous change of the blood, with which it mingles 
only to be conducted over every part of the body. 
After having by these experiments endeavoured to solve the 
still controverted question of the effects of chloroform inhaled into 
the respiratory passages, I naturally felt a desire to make applica- 
tion of the same to veterinary surger}'. I shall now communicate 
the results of my experiments on this head. 
The experiments detailed offer nothing new., They were made 
