CHYLE. 361 



contains no fatty particles or molecular base ; but it is liable 

 to variations according to the general state of the blood, 

 and that of the organ from which the lymph is derived. 

 As it advances towards the thoracic duct, and passes 

 through the lymphatic glands, it becomes, like chyle, 

 spontaneously coagulable from the formation of fibrin. 



The fluid contained in the lacteals, or lymphatic vessels 

 of the intestine, is clear and transparent during fasting, 

 and differs in no respect from ordinary lymph ; but during 

 digestion, it becomes milky, and acquires the other charac- 

 ters of chyle. 



Chyle is an opaque, whitish fluid, resembling milk in 

 appearance, and having a neutral or slightly alkaline re- 

 action. Its whiteness and opacity are due to the presence 

 of innumerable particles of oily or fatty matter, of exceed- 

 ingly minute though nearly uniform size, measuring on the 

 average about 30 ^ 00 of an inch (Gulliver). These con- 

 stitute what Mr. Gulliver appropriately terms the molecular 

 lase of chyle. Their number, and consequently the opacity 

 of the chyle, are dependent upon the quantity of fatty 

 matter contained in the food. Hence, as a rule, the chyle 

 is whitest and most turbid in carnivorous- animals ; less so 

 in Herbivora; while in birds it is usually transparent. 

 The fatty nature of the molecules is made manifest by 

 their solubility in ether, and, when the ether evaporates, 

 by their being deposited in various-sized drops of oil.* 

 Yet, since they do not run together and form a larger 

 drop, as particles of oil would, it appears very probable 

 that each molecule consists of oil coated over with albu- 

 men, in the manner in which, as Ascherson observed, oil 

 always becomes covered when set free in minute drops in 

 an albuminous solution. And this view is supported by 

 the fact, that when water or dilute acetic acid is added to 



* Some of the molecules may remain undissolved by the ether ; but 

 this appears to be due to their being defended from the action of the 

 ether by being entangled within the albumen which it coagulates. 



