DIGESTION VISIBLE TO THE EYE. 
385 
clear transparent fluid, without smell, slightly saltish (probably 
from the admixture of mucus), and very perceptibly acid. Its 
taste, he says, resembles that of thin mucilaginous water, slight- 
ly acidulated with muriatic acid. It is readily diffusible in 
water, wine, or spirits, and effervesces slightly with alkalies — a 
direct proof of its acid nature. It coagulates albumen, and is 
powerfully antiseptic, checking the progress of putrefaction in 
meat. When pure it will keep for many months, but when dilut- 
ed with saliva it becomes fetid in a few days. According to Pro- 
fessor Dunglison, to whom some was submitted by Dr. Beaumont 
for analysis, it contains free muriatic and acetic acids, — phos- 
phates and muriates with bases of potassa, soda, magnesia , and 
lime, together with an animal matter soluble in cold, but insolu- 
ble in hot water. Tiedemann and Gmelin, again, describe it as 
composed principally of muriatic and acetic acids, mucus, saliva, 
osmazorne , muriate and sulphate of soda, with little or no albu- 
men ; and, according to the same physiologists, the proportion 
of acid is always greatest when vegetables or other substances of 
difficult digestion constitute the chief part of the diet. Other 
chemists give an analysis somewhat different from either of 
these; a circumstance which was, indeed, to be expected, con- 
sidering not only the differences caused by variations of diet, 
but also the necessarily different degrees of . purity of the fluid 
submitted to examination.” 
“ Another important principle, which Dr. Beaumont conceives 
to be established by his numerous experiments, and which forced 
itself upon him by degrees, is, that in health the gastric secretion 
always bears a direct relation to the quantity of aliment naturally 
required by the system; so that, if piore than this be taken, 
there will necessarily be too small a supply of the juice for the 
digestion of the whole. The principle here laid down is in per- 
fect harmony with the sympathy which we have seen to exist be- 
tween the stomach and the rest of the body, and therefore not 
only is highly probable in itself, but, if sound, will prove a most 
valuable guide in the practical regulation of diet. 
“ The gastric secretion, and the appearance of the villous coat, 
undergo great modifications during disease, and on this subject 
also Dr. Beaumont’s observations are highly valuable ; because, 
instead of merely inferring, as others are obliged to do, he enjoyed 
the privilege of seeing with his eyes what was actually going on. 
In tbe course of his attendance on St. Martin, he found that, 
whenever a feverish state was induced, whether from obstructed 
perspiration, from undue excitement by stimulating liquors, from 
overloading the stomach, or from fear, anger, or other mental 
emotion depressing or disturbing the nervous system, the villous 
VOL. IX. 3 E 
