in which Death is produced by vegetable Poisons. 207 
the brain, it may, in some instances, at least, be made to re- 
cover, if respiration is artificially produced, and continued for 
a certain length of time. 
From analogy we might draw some conclusions respecting 
the mode in which some other vegetable poisons produce 
their effects on the animal system ; but I forbear to enter into 
any speculative inquiries ; as it is my wish, in the present com- 
munication, to record such facts only, as appear to be estab- 
lished by actual experiment. 
Addition to the Croonian Lecture for the Tear 1810. 
In the experiments formerly detailed, where the circulation 
was maintained by means of artificial respiration after the head 
was removed, I observed that the blood, in its passage through 
the lungs, was altered from a dark to a scarlet colour, and 
hence I was led to conclude that the action of the air produced 
in it changes analogous to those, which occur under ordinary 
circumstances. I have lately, with the assistance of my friend 
Mr. W. Brande, made the following experiment, which ap- 
pears to confirm the truth of this conclusion. 
An elastic gum bottle, having a tube and stop-cock con- 
nected with it, was filled with about a pint of oxygen gas. 
The spinal marrow was divided in the neck of a young rabbit, 
and the blood-vessels having been secured, the head was re- 
moved, and the circulation was maintained by inflating the 
lungs with atmospheric air for live minutes, at the end of 
which time the tube of the gum bottle was inserted into the 
trachea, and carefully secured by a ligature, so that no air, 
might escape. By making pressure on the gum bottle, the 
