400 DIGESTION. 



two hours at a temperature a little below the boiling point, 

 by which all the saponifiable fats are dissolved. The mix- 

 ture is then largely diluted with water, thrown upon a 

 filter, and washed until the fluid which passes through is 

 neutral and perfectly clear. The filter is then carefully dried, 

 and the residue washed out with ether. The ether solution 

 is then evaporated, extracted with boiling alcohol, and the 

 alcoholic solution evaporated. The residue of this last evap- 

 oration is composed of pure stercorine. 



"When first obtained, the stercorine is a clear, slightly 

 amber, oily substance, about the consistence of Canada bal- 

 sam used in microscopic preparations. In four or five days 

 it begins to show the characteristic crystals. These are few 

 in number at first, but soon the entire mass assumes a crys- 

 talline form. In one analysis we obtained from seven and a 

 half ounces of normal human faeces (the entire quantity for 

 the twenty-four hours), 10'4rl7 grains of stercorine, the ex- 

 tract consisting of nothing but crystals. This was all the 

 stercorine to be extracted from the regular daily evacuation 

 of a healthy male twenty-six years of age and weighing about 

 one hundred and sixty pounds. In the absence of other in- 

 vestigations, the daily quantity of this substance excreted 

 may be assumed to be not far from ten grains. 



In many regards, stercorine bears a close resemblance to 

 cholesterine. It is neutral, inodorous, and insoluble in water 

 and in a solution of potash. It is soluble in ether and hot 

 alcohol, but is almost insoluble in cold alcohol. A red color 

 is produced when it is treated with strong sulphuric acid. It 

 may be easily distinguished from cholesterine, however, by 

 the form of its crystals. It fuses at a low temperature, 96*8 

 Fahr., while cholesterine fuses at 293 Fahr. 



Stercorine crystallizes in the form of thin delicate nee- 

 dles, frequently mixed with clear rounded globules, which 

 are probably composed of the same substance in a non-crys- 

 talline form. When the crystals are of considerable size, the 

 borders near their extremities are split longitudinally for a 



