BLOOD. 361 



5. Oleic and Margaric acids. Boudet seems first to have no- 

 ticed these acids in the serum of blood, and to have extracted 

 them in the state of a soap.* They were afterwards obtained 

 by Lecanu. When the yellow alcoholic liquid, described in the 

 last paragraph, from which the cholesterin has precipitated by 

 spontaneous evaporation, is evaporated over the vapour bath, 

 there remans a yellowish transparent matter, evidently a mixture 

 of an oily, yellow, and colourless solid matter. 



The yellow oily matter was liquid, very soluble in cold alco- 

 hol, which it rendered acid ; very soluble in alkaline solutions, 

 and not capable of being distilled over with water. It was oleic 

 acid. 



The colourless solid substance had a pearly lustre, was very 

 little soluble in cold alcohol ; but very soluble in cold ether. 

 It was very soluble in boiling alcohol, which it rendered acid, B and 

 was deposited when the liquid cooled in pearl-coloured plates. 

 It melted between 131 and 136, and when calcined left no al- 

 kaline residue. It was margaric acid. 



6. Serolin. This substance was detected in the serum of blood 

 by M. Boudet in 1833.f He obtained it by setting aside a hot 

 alcoholic decoction of dried serum. As the alcohol cooled, a 

 white matter, having a slightly pearly lustre, was deposited. It 

 was the serolin. 



7. Cerebrate. This substance was first discovered in the se- 

 rum of blood by Chevreul. The discovery was confirmed by 

 the subsequent researches of Boudet. It was obtained by this 

 last chemist in the following way : 



Serum of blood, dried and deprived of every thing which boil- 

 ing water is capable of extracting, was reduced to powder and 

 treated with boiling alcohol. The alcoholic solution on cooling 

 deposited serolin. The filtered liquid was distilled till three- 

 fourths of the alcohol passed over. The residue became muddy ; 

 but nothing was deposited. Being cautiously evaporated to dry- 

 ness, a yellowish brown matter remained, of the consistence of 

 turpentine, which formed an emulsion with cold water. Its taste 

 was acrid and analogous to the fatty matter of the brain. When 

 triturated with cold alcohol of 0-8428, till nothing more would 

 dissolve the substance that remained possessed the characters of 

 the fatty matter of the brain. 



* Journ. de Pharmacie, xix. 264. f Ibid. xix. 299. 



