286 



CONSIDERATION OF CARBON COMPOUNDS. 



acetate more acetic acid, the neutral acetate is obtained. It 

 forms deep green, prismatic crystals, which are soluble in water. 



Valerianic acid, HC 5 H 9 2 ( Valeric acid). This acid occurs in 

 valerian root and angelica root, from which it may be separated; 

 it is, however, generally obtained by oxidation of amyl alcohol 

 bp potassium dichromate and sulphuric acid. After oxidation 

 has taken place the mixture is distilled, when valerianic acid 

 with -some valerianate of amyl distils over. The change of 

 amyl alcohol into valerianic acid is analogous to the conversion 

 of ethyl alcohol into acetic acid : 



C 5 H H HO + 20 = 



Amyl 



alcohol. 



HC 5 H 9 2 



Valerianic 

 acid. 



H. 2 U. 



tratmg, 



Pure valerianic acid is an oily, colorless liquid, having a pene- 

 highly characteristic odor; it is slightly soluble in 

 water, but soluble in alcohol; it boils at 185. 



Several of the salts of valerianic acid are officinal ; they are 

 the valerianate of iron, of ammonium, of zinc, and of quinine. The 

 three last-named compounds are white salts, whilst the ferric 

 valerianate has a dark-red color; the ammonium salt is easily 

 soluble in water, the three other compounds are insoluble or 

 nearly so. 



Oleic acid, Acidum oleicum, HC 18 H 33 2 = 282. As shown by its 

 formula, oleic acid does not belong to the above-described series 

 of fatty acids of the composition C n H 2n O 2 , but to a series having 

 the general composition C n H 2n _ 2 O 2 . 



Oleic acid is a constituent of most fats, especially of fat oils. 

 Thus, olive oil is mainly oleate of glyceril. By boiling olive 

 oil with potassium hydrate, potassium oleate is formed, which 

 may be decomposed by tartaric acid, when oleic acid is liberated. 



Oleic acid is a nearly colorless or yellowish, odorless, taste- 

 less, neutral liquid, insoluble in water, soluble in alcohol, chlo- 

 roform, oil of turpentine, and fat oils, crystallizing near the 

 freezing-point of water; exposed to the air it decomposes and 

 shows then an acid reaction. Lead oleate is soluble in ether, 

 lead palmitate and lead stearate are not. 



The officinal oleate of 'mercury and oleate of veratrine are ob- 



