424 OF NUTRITION. 



is generally supposed that the milky colour of the chyle is owing to these ; but 

 Mr. Gulliver has recently pointed out* that it is really due to an immense mul- 

 titude of far more minute particles, which he describes as forming the mole- 

 cular base of the chyle. These molecules are most abundant in rich, milky, 

 opaque chyle ; and in poorer chyle, which is semi-transparent or opaline, the 

 particles float thinly or separately in the transparent fluid, and often exhibit 

 the vivid motions common to the most minute molecules of various substances. 

 Such is their minuteness, that, even with the best instruments, it is impossible 

 to form an exact appreciation either of their form or their dimensions. They 

 seem, however, to be generally spherical ; and their diameter may be estimated 

 at between 1 -36,000th and 1 -24,000th of an inch. Their chemical nature is 

 as yet uncertain : they are remarkable for their unchangeableness, when sub- 

 jected to the action of numerous other re-agents, which quickly affect the 

 proper Chyle-corpuscles ; and they are readily soluble in Ether, the addition 

 of which causes the whole molecular base instantly to disappear, not a particle 

 of it remaining ; whence it may be inferred that they consist of oily or fatty 

 matter. The milky colour, which the serum of blood sometimes exhibits, is 

 due to an admixture of this molecular base ; it is most common in young ani- 

 mals that are suckling; but it is not uncommon in adults, and is not to be 

 attributed to an absorption of milk into the chyle, as the physical properties of 

 the two are quite different.. 



564. During the passage of the Chyle through the absorbents on the intes- 

 tinal edge of the Mesentery, towards the Mesenteric Glands, its character 

 changes in several important particulars. The presence of Fibrin begins to 

 manifest itself, by the slight coagulability of the fluid when withdrawn from 

 the vessels ; and while this ingredient increases, the Albumen and the Oil- 

 globules gradually diminish in amount. The Chyle drawn from the neigh- 

 bourhood of the mesenteric glands exhibits the Corpuscles regarded as charac- 

 teristic of that fluid ; these are peculiarly abundant in the fluid drawn from 

 the glands themselves ; and they are constantly found in it, through its whole 

 subsequent course. The Chyle-corpuscles are much larger than the molecules 

 just described, and an examination of their characters presents no difficulty. 

 The diameter varies from 1-71 10th to l-2600th of an inch; the average being 

 about l-4600th. They are usually minutely granulated on ths surface, seldom 

 exhibiting any nuclei, even when treated with acetic acid; but sometimes 

 three or four central particles may be distinguished within them. During the 

 passage of the Chyle through the mesenteric glands, a further increase in the 

 proportion of Fibrin takes place ; and the resemblance of the fluid to blood 

 becomes more apparent. The Chyle drawn from the vessels intermediate 

 between these and the central duct, possesses a pale reddish-yellow colour ; 

 and, when allowed to stand for a time, undergoes a regular coagulation, sepa- 

 rating into dot and serum. The former is a consistent gelatinous mass, which, 

 when examined with the microscope, is found to include the Chyle-corpuscles, 

 each of them being surrounded by a delicate film of oil: the Fibrin of which 

 it is principally composed, differs remarkably from that of the blood, in its infe- 

 rior tendency to putrefaction ; whence it may be inferred that it has not yet 

 undergone its complete vitalization. The serum contains the Albumen and 

 Salts in solution, and a proportion of the Chyle-corpuscles suspended in it. It 

 is curious, however, that considerable differences in the perfection of the coagu- 

 lation, and in its duration, should present themselves in different experiments. 

 Sometimes the chyle sets into a jelly-like mass, which, without any separation 

 into coagulum and serum, liquefies again at the end of half an hour, and 



than in that of the Herbivora; their diameter has been observed to vary from l-25,000th 

 to l-2000th of an inch. 

 * Dublin Medical Press, Jan. 1, 1840, and Gerber's General Anatomy, Appendix, p. 88. 



