268 EXCRETION. 



sider the two substances identical. 1 In 1814, Chevreul gave 

 a full description of cholesterine, and extracted it from the 

 bile of the human subject and some of the inferior ani- 

 mals. 3 It was afterward found by different observers, in 

 gall-stones, intestinal concretions, cysts, and tumors. In 

 1830, Denis described a substance in the blood, which he 

 thought was cholesterine, and its discovery in this fluid is 

 attributed to him by most authors ; but in 1838, he acknowl- 

 edged the error of his first observation, 8 and admits that 

 cholesterine, with a new substance analogous to it, called 

 seroline, was discovered in the blood, in 1833, by Boudet. 4 



Cholesterine is now recognized as a normal constituent 

 of various of the tissues and fluids of the body. Most 

 authors state that it is found in the bile, blood, liver, nervous 

 tissue, crystalline lens, meconium, and faecal matter. "We 

 have found it in all these situations, with the exception of 

 the faeces, 6 where it does not exist normally, having been 

 transformed into stercorine in its passage down the intestinal 

 canal. 8 



In the fluids of the body, cholesterine exists in solution ; 

 but by virtue of what constituents it is held in this condition, 



described by Fourcroy was undoubtedly cholesterine; but it remained for 

 Chevreul to describe its properties accurately and give it the name by which it 

 is now known. The observations of Chevreul will be referred to further on. 



1 FOURCROY, Deuxieme memoir e sur les matieres animates trouvees dans la Ci- 

 metiere des Innocens d Paris. Annales de chimie, Paris 1791, tome viii., p. 

 62, et seq. 



2 CHEVREUL, Reclierches chimiques sur plusieurs corps gras, Cinquieme me- 

 moire. Des corps qu'on a appelle adipocire. Annales de chimie, Paris, 1815, toine 

 xcvi., p. 7. 



3 DENIS, Essai sur ^application de la chimie d V etude physiologique du sang de 

 rhomme, Paris, 1838, p. 147. 



4 BOUDET, Nouvelles rechercJies sur la composition du serum du sang humain. 

 Annales de chimie et de physique, Paris, 1833, tome lii., p. 337. 



5 For a table of the quantities of cholesterine in various situations, see an 

 article by the author, on a New Excretory Function of the Liver. American Jour- 

 nal of the Medical Sciences, Philadelphia, 1862, New Series, vol. xliv., p. 313. 



6 See vol. ii., Digestion, p. 399, et seq. 



