CHYLE. 645 



Although chyle has essentially the same constituents, whatever may 

 be the food taken, and separates equally into a clot and serous portion, 

 the character of the aliment may have an effect upon the relative quan- 

 tity of those constituents, and thus exert an influence on its compo- 

 sition. That it scarcely ever contains adventitious substances will be 

 seen hereafter ; but it is obvious, that if an animal be fed on diet con- 

 trary to its nature, the due proportion of perfect chyle may not be 

 formed ; and that, in the same way, different alimentary articles may 

 be very differently adapted for its formation. MM. Leuret and Las- 

 saigne, 1 indeed, affirm, that in their experiments they found the chyle 

 differ more according to the nature of the food than to the animal spe- 

 cies ; but that, contrary to their expectation, the quantity of fibrin in 

 it bore no relation to the more or less nitrogenized character of the ali- 

 ment. They assign it, as constituents, fibrin, albumen, fatty matter, 

 soda, chloride of sodium, and phosphate of lime. 



Messrs. Tiedemann and Gmelin have communicated the following 

 data in regard to the influence of diet on the chyle. The experiments 

 were made on dogs, and the chyle was taken from the thoracic duct. 

 First* After taking cheese, the chyle coagulated slightly. The clot 

 was little more than a pale red transparent film, and the serum slightly 

 milky. It contained water, 950-3 ; clot, 1-71 : residue of serum, 48-0. 

 Secondly. After the use of starch, the chyle was of a pale yellowish- 

 white colour, and coagulated rapidly. It contained water 930*0 ; clot 

 and residue of serum, 70-0. The clot was of pale red colour. Thirdly. 

 After taking flesh, and bread and milk, it was of a reddish- white colour, 

 and coagulated rapidly, the clot being of a pale red tint, and the serum 

 very milky. It consisted of water, 915-3 ; clot, 2-7 ; residue of serum, 

 83-8. Fourthly. After the use of milk it presented a milky appearance, 

 and the clot was transparent, and of a pale red colour. Fifthly. After 

 bread and milk, it contained water, 961-1 ; clot 1/9 ; residue of serum, 

 37*0. Sixthly. After flesh, bread, and milk, it was of a yellowish red 

 colour; coagulated firmly, separating into a bright red clot, and turbid yel- 

 low serum; and contained water, 933*5; clot, 5-6; residue of serum, 60-9. 2 



The chief object of Dr. Marcet's experiments was to compare the 

 chyle from vegetable, with that from animal food, in the same animal. 

 The experiments made on dogs led him to the following results. The 

 specific gravity of the serous portion is from 1-012 to 1*021, whether 

 it be formed from animal or vegetable diet. Vegetable chyle, when sub- 

 jected to analysis, furnishes three times more carbon than animal 

 chyle. The latter is highly disposed to become putrid ; and this change 

 generally commences in three or four days ; whilst vegetable chyle may 

 be kept for several weeks, and even months, without being putrid. 3 

 Putrefaction attacks rather the coagulum of the chyle than its serous 

 portion. The chyle from animal food is always milky ; and, if kept at 

 rest, an unctuous matter separates from it, similar to cream, which swims 

 on the surface. The coagulum is opaque, and has a rosy tint. On the 



1 Recherches sur la Digestion, Paris, 1825. 2 Simon, op. cit, p. 358. 



3 M. Thenard has properly remarked, that the difference in the time of putrefaction of 

 these two substances, appears very extraordinary. It is, indeed, inexplicable. Traite de 

 Chitnie Elementaire, &c., 5eme edit., Paris, 1827. 



