632 
ON WOUNDS PENETRATING INTO THE CHEST 
OF THE HORSE. 
EXPERIMENTS MADE WITH A VIEW TO ILLUSTRATE THEIR CONSEQUENCES 
AND THE PROPER TREATMENT OF THEM. 
By MM. U. Leblanc, F.&., and A. Trosseau, M.D, 
[Continued from page 584.] 
5. Simple wounds of the parietes of the thorax , with hemorrhage 
from an intercostal artery; the effusion of blood into the pleural 
cavity , with the introduction of air into the chest . 
If after having produced an effusion of blood into the chest by 
dividing an intercostal artery, as was described in the last journal, 
a communication is established between the external air and the 
pleural cavity by means of a canula, not only the effects ordinarily 
produced by the agency of the air are observed, but others that 
are the consequence of the effusion of blood. The air mixes with 
a portion of the effused blood, and we hear, a little while after 
the introduction of the air, a spumous sound, if we may so call 
it, and the air almost always passes, although unequally, into both 
of the thoracic cavities. The animal under experiment feels much 
difficulty in breathing, his nostrils are dilated, and the aim of the 
nose are curled, &c.; and we have constantly witnessed the death 
of the patient after this experiment, even although the communica¬ 
tion with the external air did not last more than half an hour. In 
these cases, however, the communication with the air was constant, 
and had taken place through a canula a quarter of an inch in 
diameter. It is not the same when the passage for the air is 
narrower, and when the communication is only for an instant at 
a time, and interrupted, as is usually the case when wounds of 
this kind occur accidentally. 
The air in the pleural cavity acts in this case not only by the 
pernicious agency which has been already described, but by its 
property of effecting an important change in the blood itself— 
depriving it of its life, if we may so express ourselves,—rendering 
it a foreign body, and thus preventing it from being absorbed as 
when there was no communication between the thoracic cavity 
and the external air. We see the mass of blood isolating itself 
in the pleurae by means of false membranes, which envelop the 
clot either partially or entirely. The clot becomes changed—it 
speedily putrefies under the more disadvantageous circumstances, 
that is, when the communication with the air is permanent, or 
lasts a considerable time. The blood is of a black hue through the 
whole of its mass ; then it becomes livid, assumes various colours 
on its surface, exhales a disagreeable odour, and begins to pu- 
