1908.|] Destiny of Cholesterol in the Animal Organism. 231 
colour effects on cooling. Three crops of crystals, examined with the 
polariscope in chloroform solution, gave the following results :— 
(1) [a]p = +23°07, (2) [eJp = +23°7, (8) [a]p = 422°. 
It thus appears identical with the coprosterol of human feces described by 
Bondzynski and Humnicki.* To confirm this point, the whole of the material 
was converted to the acetate, which was repeatedly crystallised from alcohol 
and acetone. The highly pure ester was saponified with sodium ethylate in 
ethereal solution, and the product twice recrystallised from alcohol. A sample 
of human coprosterol was similarly worked up and purified, and in the 
following table we give a comparison of their properties. 
Coprosterol, dog. Coprosterol, human, 
Crystallises from alcohol in Long flexible needles Long flexible needles. 
IMeIGIMG; PONE... 65.00.5020 Falls together at 98°; melts, Falls together at 98°; melts, 
99°—100° $9°—100°. 
Rotation [a ]pin chloroform + 23°.°7 + 23° °5. 
RCOEMUO se hes pasio es baceucees o¥eiepi Needles from alcohol; m.p., | Needles; m. p., 88°—89°. 
88°—89° 
Benzoate (prepared by the Leaves, difficultly soluble in Leaves, difficultly soluble in 
pyridine method) alcohol; m.p., 122°—123° | alcohol; m. p., 121°—122°. 
The mother liquors, on standing, set to a brown oily mass. This was put 
on a porous tile and the oily part drained away. The dry solid matter was 
heated to 140° with benzoyl chloride, and then treated with hot alcohol. 
It dissolved readily with the exception of a small quantity which was only 
got into solution with difficulty. On cooling, about 0°2 gramme of white 
crystalline matter separated. This was recrystallised from alcohol and 
melted at 141° to a turbid lquid, which on cooling showed the brilliant 
colours of cholesterol benzoate. The mother liquors, on spontaneous evapora- 
tion, yielded a small quantity of brown crystalline matter. This was 
very easily soluble in absolute and dilute alcohol, but was not further 
investigated. 
‘The yield of coprosterol was thus 16 to 17 grammes, or 1:14 to 1:2 per 
day. | 
(d) Cooked Horseflesh—After the last experiment the dog was allowed to 
rest for a month, and was then fed for a month on porridge made from coarse 
oatmeal, and water. The product was unfortunately lost. The animal was 
then given another month’s rest with aneordinary mixed diet. At the end 
of this period it was fed for 17 days on cooked horseflesh with scarcely any 
fat. In the middle of this experiment there was an interval of four days, 
*® ° Zeit. Physiol. Chemie,’ vol. 22, p. 396. 
