648 
COAGULATION OF THE BLOOD. 
sanguinis, but the corpuscles also were present in the serous 
cavity, yet no coagulation took place in contact with its walls. 
I think it probable, though not yet proved, that all living 
tissues have these properties with reference to the blood. We 
know that the interstices of the cellular tissue contain coagu- 
lable fluid, and I have seen anasarcous liquid coagulate after 
emission; but this, indeed, may possibly have been merely 
liquor sanguinis, coagulating in consequence of slight admix¬ 
ture of blood-corpuscles from the wounds made in obtain¬ 
ing it. 
Looking now at the principal results which we have arrived 
at, it must, in the first place, be admitted that the ammonia 
theory is to be discarded as entirely fallacious. The fact that 
this theory is exceedingly plausible, and has been supported 
by many ingenious arguments and experiments, is of course 
no reason why we should retain it if unsound. On the con¬ 
trary, the more specious it is, the more necessary is it that it 
should be effectually cleared away; for it mystifies the sub¬ 
ject of coagulation most seriously; and I may say, for my 
own part, that it has cost me an amount of experimental 
labour of which the illustrations brought forward this evening 
convey but little idea. Still these have been, I trust, suf¬ 
ficient to show that the coagulation of the blood is in no 
degree connected with the evolution of ammonia, any more 
than with the influence of oxygen or of rest. The real cause 
of the coagulation of the blood, when shed from the body, is 
the influence exerted upon it by ordinary matter, the contact 
of which for a very brief period effects a change in the blood, 
inducing a mutual reaction between its solid and fluid con¬ 
stituents, in which the corpuscles impart to the liquor 
sanguinis a disposition to coagulate. This reaction is pro¬ 
bably simply chemical in its nature; j T et its product, the 
fibrin, when mixed with blood-corpuscles in the form of an 
undisturbed coagulum, resembles healthy living tissues in 
being incapable of that catalytic action upon the blood which 
is effected by all ordinary solids, and also by the tissues 
themselves when deprived of their vital properties. 
These principles have, of course, very extensive applications 
to the study of disease; but I must content myself with 
alluding very briefly to inflammation, the most important of 
all pathological conditions. 
If we inquire what is the great peculiarity of inflamed parts 
in relation to the blood as examined by the naked eye, we see 
that it consists in a tendency to induce coagulation in their 
vicinity; implying, according to the conclusions just stated, 
that the affected tissues have lost, for the time being, their 
