290 CARPENTER, ON HUMAN PHYSIOLOGY. 
respiratory and cardiac movements ceasing within two minutes; and 
that on post-mortem examination in such cases, the stomach was 
nearly empty, whilst the blood was highly charged with alcohol ; thus 
rendering it almost certain, that not merely the final destruction of 
nervous power, but the immediate loss of sensibility, was due to the 
action of aleoholized blood upon the nervous centres. Finally, nu- 
merous experiments have been made by various physiologists, which 
have demonstrated that absorption of alimentary and other substances 
may take place from the walls of the stomach; these substances 
having been prevented from passing into the intestine by a ligature 
around the pylorus. Now, as the absorbent system does not present 
that peculiar arrangement in the coats of the stomach, which it does 
in those of the intestinal tube, there can be little doubt that the in- 
troduction of such substances into the system must be effected chiefly, 
if not entirely, through the medium of its sanguiferous capillaries. 
109. That the blood-vessels of the intestinal tube largely partici- 
pate in the introduction of soluble alimentary matter into the system, 
has been clearly proved by various observations upon the constitution 
of the blood of the mesenteric veins; these having shown that, after 
the digestion of albuminous and farinaceous or saccharine substances, 
albuminose, dextrin, grape-sugar, and lactic acid, are detectible in 
that fluid, whose usual composition is greatly altered by the presence 
of these substances, as well as by the augmented proportion of water 
which it contains. Moreover, it is asserted by Bruch,* that so large a 
quantity of fat is absorbed into the blood-vessels, that the superficial 
capillary network sometimes presents an opalescent whiteness. We 
may consider the sanguiferous vessels, then, as affording the usual 
channel by which a large part of the nutritive materials are introduced 
into the system; but these are not allowed to pass into the general 
current of the circulation, until they have been subjected to an import- 
ant assimilating process, which it appears to be one great office of the 
liver to perform, whereby they are rendered more fit for the purposes 
they are destined to serve in the economy. Of this we shall presently 
have tospeak. But the absorbent power which the blood-vessels of 
the alimentary canal possess, is not limited to alimentary substances ; 
for it is through them almost exclusively that soluble matters of every 
other description are received into the circulation. This, which may 
now be considered a well-established fact, was first clearly shown 
by the carefully conducted experiments of MM. Tiedemann and 
Gmelin,} who mingled with the food of animals various substances, 
which, by their colour, odour, or chemical properties, might be easily 
detected in the fluids of the body; after some time the animal was 
examined ; and the result was, that unequivocal traces of such 
substances were not unfrequently detected in the venous blood and in 
the urine, whilst it was only in a very few instances that any indica- 
tion of them could be discovered in the chyle. The colouring matters 
employed were various vegetable substances, such as gamboge, madder, 
and rhubarb ; the odorous substances were camphor, musk, asafcetida, 
&ec.; while, in other cases, various saline bodies, such as chloride of 
barium, acetate of lead and of mercury, and some of the prussiates, 
which might easily be detected by chemical tests, were mixed with 
the food. The colouring matters, for the most part, were carried out 
* Siebold and Kolliker’s ‘ Zeitschrift,’ April, 1853. 
+ ‘Versuche iiber die Wege auf welchen Substanzen aus dem Magen und 
Darmkanal ins Blut gelangen,’ Heidelberg, 1820. 
