ITS CHEMICAL CONSTITUENTS. 285 



becomes covered on evaporation by a colourless membrane. The 

 aqueous extract of the residue of the chyle exhibits a strongly 

 alkaline reaction, and the solution may be rendered turbid by 

 neutralising it with acetic acid. After this turbidity has been 

 removed by a more copious addition of acetic acid, ferrocyanide of 

 potassium gives rise to a considerable precipitate. The aqueous 

 extract of the residue of the chyle presents great turbidity on 

 being boiled with hydrochlorate of ammonia, as well as on the 

 addition of nitric acid. The albumen, after being thoroughly 

 washed with water, alcohol, and ether, was found to yield on 

 incineration 2'068 of mineral constituents, including a consi- 

 derable amount of alkaline salts, which effervesced on the addition 

 of acids. The supposed presence of casein in the chyle, instead of 

 being proved, seems therefore to be rendered very improbable. 



It would be an important point if we could show that the 

 peptones of the albuminous substances in the food are present in 

 the chyle, but from our ignorance of the necessary reagents, this 

 question cannot at present be decided by direct investigation. As 

 the chyle contains from 2*5 to 3'Og- of non-coagulable substances 

 which are only soluble in water, and consist of a large proportion of 

 albuminate of soda and mineral salts, it is at all events improbable, 

 to say the least, that peptones should be present in the chyle 

 discharged from the thoracic duct of the horse ; and hence the 

 question, whether the peptones are elaborated in the mesenteric 

 glands into albumen and fibrin, still continues wholly undecided. 



Our microscopical and microscopico-chemical investigations 

 prove that/fitf is contained in large quantity in the chyle, and even 

 show with some degree of probability that the chyle contains a 

 considerable quantity of non-saponified fat in the smaller lacteals, 

 whilst in the thoracic duct the proportion of saponified fat pre- 

 ponderates. I was unable by any method to obtain a crystallizable 

 fat from the saponified or non-saponified fats of the chyle of the 

 horse ; and other observers have stated that they could only dis- 

 cover a greasy and tallow -like fat, although they may not always 

 have attempted to detect the fat-crystals by the aid of the micro- 

 scope. 



Some authors profess to have found sugar in the chyle ; others 

 could not discover this substance. Trommer* believes he has 

 detected its presence in the chyle of horses by means of his own 

 sugar-test, but it is well known that many causes concur in 

 destroying the practical value of this test. Thus, for instance, the 

 * Ann. d. Ch. u. Pharm. Bd. 39, S. 360. 



