708 
PROFESSOR HARLEY ON THE INFLUENCE OF 
In 100 parts of air. 
Oxygen. 
Carbonic acid. 
Nitrogen. 
Total oxygen. 
Healthy blood of dog 
19*700 
0-409 
79*891 
20-109 
Blood of dog poisoned with woorara ... 
18-680 
1-510 
79*810 
20-190 
It will be observed that there is a slight discrepancy between the amount of oxygen 
absorbed in this and the other experiment on the action of woorara out of the body ; 
for here the oxidation has been greater than in the healthy animal. This most pro- 
bably arises, however, from some accidental cause, due to the blood being taken from 
different animals and not operated on in the same day. Unfortunately it is impossible 
to operate on both healthy and poisoned blood of the same animal at the same time, 
so that all our experiments of comparison on the blood of living auimals are liable to 
the source of error arising from the state of the body and the constitutional peculiarity 
of the animal. My former statement regarding the action of woorara, namely, that it 
diminishes oxidation and increases the exhalation of carbonic acid, at least in sheep’s 
blood, is I have little doubt correct, as I have invariably found it to be so. I might 
here quote other experiments in proof of this assertion, but in order to prevent unneces- 
sary repetition, shall delay doing so till the action of woorara is compared with that of 
other substances. 
Antiar and Aconitine. 
For the sake of brevity I shall take these two poisons together. As is well known, 
their physiological action on the animal body is, as nearly as possible, identical. They 
are both powerful cardiac poisons. So powerfully, indeed, do they act in this way, 
that when given to frogs they stop the action of the heart while the animal is otherwise 
sufficiently well to be able to spring about. This is the reverse of woorara, which 
allows the heart’s action to continue long after the rest of the body is dead. Hence 
arises the saying that we may have a dead heart in a living body with antiar and 
aconitine, and a dead body with a living heart with woorara. 
The result of the following experiment forcibly illustrates the truth of the latter 
statement. A healthy full-grown frog was pricked with the point of a poisoned arrow, 
and in the course of a few minutes its limbs gradually became paralysed. The paralysis 
soon extended itself over the body, the animal ceased to breathe, and in the course of a 
few minutes more was dead. On examining the heart about an hour afterwards, that 
organ, and that organ alone, was found still alive. Death could not be said here to have 
usurped its power, for it slowly and regularly pulsated as in life. On the following 
day the heart still continued to beat although the tissues surrounding it had assumed 
the appearance of death. Forty-eight hours after the animal had been poisoned its 
heart still continued to act regularly, and even seventy-two hours afterwards the action 
of the ventricle and auricles, though feeble, was yet distinct. On the fourth day 
(ninety-six hours after death) part of the heart died, the left auricle alone continued to 
pulsate. But now, not only was the frog dead, but its lower limbs were already shrunk 
