CHOLIC ACID. 121 



taste ; the acid is displaced from them by stronger acids, and even 

 by carbonic acid, although, on the other hand, choloidic acid 

 expels carbonic acid when heated with carbonates. The alkaline 

 salts of this acid are soluble in water and in alcohol, but not in 

 ether ; they cannot be obtained in a crystalline state. Choloidate 

 of baryta., although isomeric with the cholate, is not crystallisable, 

 and is insoluble in water, With earths and metallic oxides this 

 acid forms salts which are soluble in alcohol but insoluble in water. 



Dy sly sin C 48 H 36 O 6 (Strecker), C 50 H 36 O 6 (Mulder,) is obtained 

 from cholic or choloidic acid by one of the methods which we have 

 already mentioned ; the mass thus formed is extracted with water 

 and alcohol, arid dissolved in ether, from which it is again precipi- 

 tated by alcohol ; it is now of a grayish-white colour, and the 

 extent of its solubility depends upon the degree of its purity ; it is, 

 however, insoluble in acids and alkalies. When fused with hydrate 

 of potash, or boiled with an alcoholic solution of potash, dyslysin 

 is reconverted into choloidic acid. 



From the choloidic acid of Demargay, Berzelius has separated 

 two acids, which he has named fellic and cholinic acids ;* he, like 

 Mulder, regards choloidic acid as an admixture of these two acids ; 

 it is to be regretted that Strecker, in his otherwise admirable in- 

 vestigation, has not made that reference to these substances which 

 they deserve ; for other chemists as well as Mulder may repeat the 

 experiments and confirm the statements of Berzelius, We shall 

 content ourselves in the present place, with indicating the most 

 important points of difference between these two acids. 



Cholinic acid (C 50 H 38 O 8 Mulder) forms white and bright 

 flocculi, insoluble in water, and which, on drying, become brown 

 and pulverisable. Its baryta and lead-salts have a tendency to 

 cake together, and are almost insoluble in alcohol; the ammonia- 

 salt of this acid separates as a white, saponaceous mass. 



Fellic acid (C 50 H 40 O 10 ) forms snow-white flocculi, which 

 when dried become pulverisable ; it is slightly soluble in water, 

 and its solubility in ether is even less than that of cholinic acid. 

 Its baryta and lead-salts are soluble in alcohol. 



Redtenbacher distilled nitric acid over choloidic acid as long as 

 vapours of nitrous acid continued to be developed, and he found in 

 the receiver acetic, butyric, valerianic (?) caproic, O3nanthylic, capry- 

 lie, pelargonic, and capric acids (precisely the same as he obtained 



* [In the German these acids are termed Fellins'dure and Cholins'dure : we adopt 

 the phrase cholinic acid for the latter word, as cholic acid is a pre-engaged name. 

 o. E. v.] 



