152 PROGRESS OF VETERINARY SCIENCE AND ART. 
water, and thus an artificial pancreatic juice is formed. One 
of its most remarkable and important characters is, that on 
decomposing, it becomes red if exposed to the action of chlo- 
rine, and this may be looked upon, according to Bernard, as 
a sure test of the presence of pancreatic juice in the intestine, 
and as a means of proving the existence of the pancreas in 
some of the lower animals. 
Uses. — The pancreatic secretion acts on all alimentary 
matters, but in different degrees, and under special circum- 
stances. Fatty substances are only dissolved and absorbed 
in the intestine beyond where the pancreatic duct enters 
it, or only when the secretion mingles with the chyme. 
By artificial digestion, we find that fat is converted into 
glycerine and fatty acids, and the only liquid entering the 
intestine capable of acidifying and emulsionating fats, is the 
pancreatic ; so that it is the chief agent engaged in the pre- 
paration of chyle. This is proved by the fact, that if the 
secretion of the pancreas be suppressed, the fatty matters 
remain unaltered in the small intestines; and the chyliferous 
vessels are found to contain an opaline fluid, peculiarly poor 
in fatty principles. As long as the secretion is suppressed, 
all fat is eliminated with the faeces in its unaltered condition. 
The secreting power of the pancreas has been destroyed, as 
well as the structure of the gland, by injecting substances 
into the duct; and the symptoms manifested, were those 
observed in diseases of the pancreas in man, viz., voracious 
appetite, emaciation, and the presence of unchanged fat in 
the faeces. 
Physiologists are not agreed in opinion as to the method 
of absorption of fat in the intestine. It is, however, known 
for certain, that in mammalia it is carried into the circulation 
by the lacteals. Pequet proved that fats were poured directly 
into the venous circulation, without passing through the 
mesenteric veins and the liver; and that in the other classes 
of vertebrate animals, viz., in birds, reptiles, and fishes, 
whereas the lymphatics of the intestine are few in number, 
fat is absorbed by the portal system of veins, and carried 
directly into the general circulation through the veins described 
by Jacobson, and named after him, which pass from the vena 
porta to the inferior vena cava, and which traverse the 
kidneys ; — thus, again, the fat does not reach the liver, where 
it would be modified or arrested in its progress. 
It has before been said, that the pancreatic juice transforms 
fat into glycerine and a fatty acid. The acid is never found 
in the chyliferous vessels, so that it is perhaps neutralized in 
