98 CAPROIC ACIDS. 



2. Ordinary caproic acid (Isobutylacetic acid), 

 CH.CH 2 .CH 2 .CO.OH. Occurs, sometimes in a free 



state, sometimes in the form of the glycerin ether, in a 

 number of plants (for instance, in the blossoms of Saty- 

 rium hircinum, in the fruit of Gingko biloba, in cocoa-nut 

 oil), further in butter and many other fats ; and results 

 from the oxidation of fats and a number of albumi- 

 noid bodies. It is most readily obtained by boiling 

 amyl cyanide with an alcoholic solution of potassa. 



Colorless liquid, but slightly soluble in water, with 

 a sudorific odor ; congealing at 4-5: boiling at 195- 

 198. 



Leucine (Amidocaproic acid), CWEPfNO^ is exten- 

 sively distributed throughout the animal organism, is 

 formed by the putrefaction of urine, glue, and protein 

 substances, and by boiling them with dilute sulphuric 

 acid. Results from valeric aldehyde, the same as ala- 

 nine (p. 91) from acetic aldehyde. Lustrous, colorless 

 crystalline laminae; fuses at 170 ; sublimes when very 

 carefully heated ; when rapidly heated, it is decomposed, 

 yielding carbonic anhydride and amylamine. Soluble 

 in 27 parts cold water ; but slightly in cold alcohol, 

 more easily in hot alcohol. 



3. Isocaproic acid, Q H3 j CH.CH j C Q Q H is ob- 



tained by heating the cyanide corresponding to amy- 

 lenehydrate (p. 71) with potassa. An oil but slightly 

 soluble in water. 



C 2 TT 5 ) 



4. Pseudocaproic acid (Diethylacetic acid), ^ 2 ^ 5 ! 



CH.CO.OH. The ether of this acid (boiling point, 

 151) is produced from acetic ether by the action of 

 sodium and ethyl iodide (p. 82). The acid separated 

 from this is liquid. 



The remaining acids of this series have been but very 

 slightly investigated in regard to their constitution. 



