WOUNDS PENKTIIATING INTO THE CHEST. 
11 
began to be decomposed ; and then pleurisy commenced, and 
the death of the animal soon followed; it was hastened in pro¬ 
portion to the quantity of blood injected, and the time during 
which it had been previously exposed to the external air. If 
we waited a considerable time before we injected the blood, it 
was already partially decomposed (physically, at least) when it 
was introduced into the chest. It happened in one experiment, 
that the blood was partly solid and partly liquid, and we had con¬ 
siderable difficulty in managing the portion that was coagulated, 
and liquefying it, and getting it into the syringe. The horse on 
which this experiment was made lived only four days. We 
have sometimes found in the chest almost all the blood which 
we had injected, but there was a great quantity of bloody 
serosity effused in the chest, and inflammation, which occupied 
almost the whole of the pleura on the side at which the blood 
had been injected. W'e thought, however, that it was not pleu¬ 
risy alone that destroyed the horse—the inflammation did not 
seem to be sufficiently violent for that. It is more likely that 
the quantity of blood (eight pounds), and the decomposilion 
which that blood underwent, had more effect in producing 
death. 
10. Simple wounds into the thoracic cavity, with the injection 
of blood running from a vein during different lengths of time, 
and also with the introduction of air for a longer or shorter 
period. 
In experimenting on this kind of wounds we observed all the 
consequences related in the preceding section, and those alluded 
to in a former part of this memoir as connected with the intro¬ 
duction of air into the chest. Death invariably follows in a 
little time, when a communication is permitted between the ex¬ 
ternal air and the pleural cavities. This last complication of 
wounds in the chest is, however, more to be dreaded than any 
of the preceding. Not only is the decomposition of the blood 
accelerated, but suffocation is produced, and by which the horse 
is destroyed, much more than by any of the consequences of 
the pleurisy or pneumonia which are the necessary attendants 
on tliese wounds. These last are only beginning to appear 
when in these cases the horse is actually in the agonies of death. 
It is also reasonable to believe, that the state of decomposition 
of the blood has much to do with the speedy death of the 
animal ; for we shall see that we could have introduced into the 
chest a larger quantity of inert fluid, as water; but which would 
not have produced so speedy a death, and perliaps not have pro¬ 
duced death at all, if there is not a communication between the 
external air and the cavity of tlic chest. 
[To l)c coiiliniicd.] 
