130 ON WOUNDS PENETRATING INTO THE CHEST. 
bayonet into the left lung of a horse, and the weapon had pene¬ 
trated to tlie depth of four inches. We took care that no air should 
enter the chest. The horse did not seem to experience any in¬ 
convenience during several seconds, and no blood was discharged 
through the nostrils. We then opened the wound, and suffered 
air to enter for about two minutes. The influence of the air im¬ 
mediately manifested itself by the ordinary symptoms, and blood 
also began to run from the nostrils; the mucous membrane be¬ 
came pale, the horse fell, and died three hours afterwards. On 
opening him, we found at least six pounds of blood in the left 
pleural cavity, and the wound in the lung contained a large clot 
of red blood. In other cases, when any animals died, suffocated by 
the presence of blood in the bronchi, the wound always contained 
a clot, but it was very small. 
Wounds with a bayonet were generally less serious than those 
with a sabre. We have several times introduced the bayonet to 
the depth of four or five inches without producing death. This 
kind of wound is only serious when the weapon, after being in¬ 
troduced, is moved in different directions, for then the pulmonary 
tissue is torn ; but sometimes even in that case death does not 
immediately follow, when air is not admitted into the wound. 
Large and blunt instruments produce wounds of a very serious 
character; but these wounds are made with difficulty, and, con¬ 
sequently, are rare. Those that we have attempted have been 
with a table knife that had no point, and after we had penetrated 
the walls of the chest with another instrument; then, plunging 
the knife the whole of its length into the chest, we were enabled 
to make wounds of little depth only, and which were not followed 
by death, or by any very serious consequences. The animals 
would always have lived had we not destroyed them for the pur¬ 
pose of examination. These wounds were not followed by he¬ 
morrhage, and they explain why it happens, that, after the 
introduction of foreign bodies, long and blunt, to a very consider¬ 
able depth into the chest, the animals are not destroyed. Al¬ 
though the instrument has penetrated deeply, the lung has only 
been pressed upon, and not deeply 'wounded. 
Most of the horses that were the subjects of the preceding ex¬ 
periments lived a very little while; either they died sponta¬ 
neously, or we sacrificed them: hence it happens that the nature 
of the pulmonary cicatrix has not been fully ascertained. 
The following experiment enables us to fill this chasm :—We 
had plunged a blunt rod of iron, two inches in diameter, into 
the lung of a horse. It penetrated to a depth of eight inches, 
and was immediately drawn out again. No material bad con- 
-sequences followed. We kept him during three weeks, and in 
