EXPERIMENTS RELATING TO CONTAGIOUS DISEASES. 637 
lungs proved greatly injected; the blood within the large 
vessels was deep black and hardly coagulated, and resembled 
much currant-jelly. Frequent repetition of these experiments 
led the learned professor to the conclusion, that whenever 
putrid matter, in any quantity, is introduced into the system, 
the blood, losing its characteristic properties, becoming unfit 
for circulation through the lungs, death ensues. 
With a view of ascertaining if the gastric juice possesses any 
influence in counteracting the deleterious effects of putrefaction, 
M. Bernard, after having contrived to obtain some of this 
juice through means of a stomach fistula, mixed it with an 
equal quantity of putrid blood, leaving them together for 
eighteen hours, and then injecting the mixture into the 
jugular vein of a dog. The animal giving no signs of having 
felt anything amiss, the conclusion was come to, that gastric 
juice was endowed with the power of neutralising the dele¬ 
terious action of the putrid ferment. Spallanzani had already 
shown, that gastric juice was an antiseptic; this observation 
shows more, that the same juice has the power of robbing 
putrid matters of their hurtful qualities. 
Under certain conditions putrid miasms prove highly active .— 
These conditions are—a sufficient quantity of the miasm, an 
elevated temperature, and, we must add, individual suscepti¬ 
bility. 
We readily understand, that, for the production of the 
disease, it is necessary that the miasm should exist in sufficient 
quantity , spread about in the air, that the air reach the 
lungs sufficiently saturated for it to become introduced into 
the system. The heat also, at the time, ought to be percep¬ 
tible and continuous. Yellow fever does not prevail in cold 
seasons. In countries where the air is warm and humid it 
is, that putrid fermentation actively proceeds and acquires all 
its baneful properties. Mr. Magendie, in his experiments, 
found that more putrid matter w r as required to take effect in 
cold than in hot weather. In addition to which, every indi¬ 
vidual has his peculiar insusceptibility {resistance propre). 
So that the cause of diseases called, not without reason, 
putrid , is to be sought in the introduction into the circulation 
of putrid matters, be they in the liquid form, or in that of 
gas or vapour.— Union Medicate . 
4 Q 
VOL. XXV 
