274 Dr. Prout on the Phenomena of Sanguification, [ApRtL, 
however, to be placed beyond a doubt that the proportion of 
albuminous matter, and especially of fibrin, is much less; or at 
feast their principles exist in a much less perfect state in the 
chyle as immediately taken up from the intestines, than as it 
exists in the thoracic duct, and about to enter the sanguiferous 
system. A portion of these albuminous principles, therefore, is 
evidently either formed altogether, or its formation is com- 
pleted during the passage of the chyle through the lacteal 
vessels, Perhaps the last view of the subject is most probable, 
and it has accordingly been in conformity with this view that 1 
have ventured to call by the name of incepient albumen a pecu- 
liar principle uniformly found in the chyle of the mammalia, and 
which appears to decrease in quantity as the two albuminous 
principles increase. Concerning the nature of this principle, 
various opinions have been entertained. One of the oldest and 
most common has been, that it is similar to the caseous principle 
of milk, and the chyle in consequence was long considered as 
analogous to milk in its properties. What makes the resem- 
blance still more striking is, that in chyle an oily or butyraceous 
fluid is very often present, which, rising to the top of the serum, 
in conjunction with the caseous-like prmciple of which we have 
been speaking, form an appearance exactly resembling the 
eream of milk, and these principles are oftenso abundant, espe- 
cially in the chyle of animals fed on flesh, that, as Dr. Marcet, 
has observed, they may be very readily detected even in the blood 
itself. Vauquelin remarked the near resemblance of this fatty 
matter to that which he extracted from the brain; and I had 
made the same remark before I had seen Vauquelin’s paper, not 
indeed with respect to the fatty matter (for I believe none exists 
naturally, in the cerebral mass of the mammalia at least), but 
with respect to the peculiar matter which has been compared to 
the caseous part of milk, and which certainly very closely resem- 
bles in its chemical properties the substance of the brain. Hence 
I once thought it likely that this principle was designed to form, 
the cerebral end nervous substance; but this opinion I must 
confess is founded on very slender grounds, and the probability. 
is much greater that it is nothing but the albuminous contents 
of the blood in an imperfect state. 
But it will be doubiless asked, if albumen be formed in the 
duodenum, why it is not a// formed there. To this it may be 
answered, that the formation of albumen appears to require a 
certain time to be completed; for 1 have umformly found the 
greatest quantity of albumen not immediately below the pylorus, 
where we might expect to find it if its formation were instanta- 
neous, but at some distance further down: we may, therefore, 
conclude with Dr. Marcet, that in those animals whose food is 
productive of a great deal of chyle, and especially in carnivorous 
animals, this fluid is taken up by the lacteals, and even some- 
times reaches the blood, before it can actually be converted into~ 
