CAPROIC ACIDS. 97 



The derivatives of valeric acid are perfectly analo- 

 gous to those of acetic and propionic acid. 



Amidovaleric acid (Butalanin), C 5 H ir N0 2 , occurs 

 in the spleen and in the pancreas of the ox. Is formed 

 by heating bromvaleric acid with ammonia. Colorless 

 laminae; easily soluble in water. When carefully 

 heated, sublimable without decomposition, without 

 previous fusion. Combines, like glycocol, with bases 

 and acids. 



The valeric acid from valerian root, as well as that 

 obtained by oxidation of amyl alcohol and of leucine 

 from different albuminoid substances, appears almost 

 always to consist of two acids in varying proportions, 

 one of which is the optically inactive isobutylformic 

 (isopropylacetic) acid, while the other is optically active. 

 The barium salt of the latter is distinguished by being 

 more easily soluble and by crystallizing less readily. 



The optically active valeric acid (probably methylethyl- 

 acetic acid) boils, at the most, 1 to 1.5 lower than the 

 inactive acid ; its specific gravity is higher, 0.9505 at 

 0. Its power to act upon polarized light is completely 

 removed by heating it with a few drops of concentrated 

 sulphuric acid. 



6. Caproic Acids. 



Of the eight acids of this composition, whose exist- 

 ence is indicated by the theory, four are known. 



1. Normal caproic acid, CH 3 .CH 2 .CH 2 .CH 2 .CH 2 . 



CO. OH. Is prepared by treating normal amyl cyanide 

 with alcoholic potassa. Clear liquid, of a sharp, acid 

 taste ; does not mix with water ; boiling point, 204.5- 

 205; specific gravity, 0.9499 at 0. 



The caproic acid, obtained by oxidation of the 

 mixture of alcohols from the hexyl hydrides of petro- 

 leum and maimite, is probably also normal caproic acid. 



