498 
DR. PROUT ON ANIMAL CHEMISTRY. 
Now, in the point of view in which we are at present consider¬ 
ing the subject, the digestive process may be supposed to consist 
in the reduction of the alimentary substances to the lowest pos¬ 
sible state (to the state, as it were, of infancy), by combining 
them with water, by which they are rendered soluble, or nearly so, 
in that fluid—a fact that must be familiar to every one who has 
examined the chyle, the characters of which, from the large quan¬ 
tity of combined water present, are so delicate, and so faintly 
marked, that, though capable of undergoing a species of coagula¬ 
tion, yet this is so imperfect that it is destroyed by the slightest 
motion, and even by the simple drainage of the watery portions 
from the more fixed, which are thus reduced to a few delicate 
fibres. 
This combination of the alimentary substances with water, by 
which at the same time their solution is effected, seems to be 
chiefly brought about by the agency of a fluid secreted by the 
stomach itself. The alimentary matter previously divided by 
mastication, and mixed with the saliva and other fluids, is 
brought in contact with this secretion, when it soon becomes 
more or less a fluid. Of this important secretion, chlorine, in 
some state or other of combination, is an element (apparently a 
necessary element, for it is always more or less present), and by 
its powerful agencies contributes mainly to effect this important 
union. This elementary principle, thus so intimately connected 
with the reducing process, is, perhaps, one of the most frequent 
subjects of derangement; and instead of chlorine, or a little free 
muriatic acid, an immense quantity of free muriatic acid is elicited, 
which not only proves the source of much secondary uneasiness, 
but more or less retards the process of reduction itself. The source 
of this chlorine or muriatic acid, unless we suppose it to be gene¬ 
rated, which is an unnecessary hypothesis, must be the common 
salt existing in the blood, from which the secretion takes place; 
and it may be asked, what is the nature of the action thus capable 
of decomposing such a compound ? We know of one agent capa¬ 
ble of exerting this power, namely, electricity; which agent, in a 
former lecture, we attempted to shew is employed by the animal 
economy in its operations, in the same way, and on the same 
principle, that it employs the materials themselves. To the im¬ 
mediate agency of this principle, therefore, the decomposition may, 
perhaps, be fairly referred; but the question here arises, what 
becomes of the soda after the muriatic acid has been separated ? 
This, of course, remains behind in the blood, and a portion of it 
no doubt goes to keep up that weak alkaline condition essential 
to the blood as a fluid ; but a large proportion of it probably goes 
to the liver, and is there elicited in combination with the biliary 
