660 REVIEW.—RENAULT ON TRAUMATIC GANGRENE. 
tumefied, hot and painful about the third or fourth day after the 
operation or accident. That swelling makes rapid progress, and 
is accompanied by oedema and emphysema at its circumference, 
which prevents or arrests all suppuration—gives birth to a succes¬ 
sion of phenomena, which generally become more and more alarm¬ 
ing, and which will cause the death of the animal, if not opposed 
in time by proper treatment. 
“ What is the cause of these phenomena so extraordinary ? 
Where this inverse march to the ordinary progress of wounds well 
treated] M. Renault has given us the proper solution to these 
questions. 
It results, according to him, from the influence which the air ex¬ 
ercises on the blood deposited on the surface of the -wounds. The 
air by its aflinities determines the decomposition and the putrid 
fermentation of the blood or animal matter contained in the wound. 
The products of this fermentation impregnate the membrane with 
which they come in contact, and destroy the nervous influence on 
these tissues. They themselves, macerated and broken dowm, par¬ 
ticipate without resistance in the putrid change, and act on the 
neighbouring tissues in the same manner that they have been acted 
upon, and thus the evil rapidly spreads. 
The influence of these putrid products is at first altogether local; 
but the vessels which traverse the tissues impregnated with the 
fluids resulting from decomposition are not slow in imbibing them, 
and soon, this vitiated matter mingles and circulates with the blood, 
and exercises its deleterious influence over the whole frame. Such 
is the cause of traumatic gangrene, and of the general infection 
Avhich ensues.” 
Such is the theory which M. Renault advocates in his memoir, 
and which he supports by the narration of numerous cases. These 
he divides into three classes. The first contains the symptoms, 
progress, duration, and termination of gangrene. The second con¬ 
tains the history of numerous cases in which gangrene does not 
appear until after the opening of a cavity containing effused blood, 
and shewing that the intimate connexion between the action of the 
air, and the phenomena of gangrene, truly assume, indeed, the rela¬ 
tion of cause and effect. The third illustrates the etiology of gangrene 
by the results of curative treatment. In the human being, wounds 
often cicature by the first intention, and it is always easy, by ap¬ 
propriate bandages, to prevent the access of air to the wound. 
In the surgical treatment of our larger domestic animals, the heal¬ 
ing by the first intention is rare, and the wound often and long 
remains exposed to the influence of the air. This is the reason why 
gangrene in the human being is comparatively seldom produced 
bv this cause, and whv its character is also essentiallv different. 
