954 OILY ACIDS. 



prism of rhombic base, greatly resembling tartaric acid ; they 

 are persistent in air. (Liebig's Traite, ii, 122). 



Kinic acid is soluble in 2 parts of boiling water ; it is also 

 soluble in alcohol. By dry distillation it yields a volatile crys- 

 talline acid, of which little is known. Kinic and gallic acids 

 appear to be related ; indeed gallic acid, which is C 7 H 3 O 5 , may 

 be considered as a kinic acid C 7 H 4 O 4 , in which 1 equivalent of 

 hydrogen is replaced by 1 equivalent of oxygen (Liebig). 



Kinates. All the kinates are soluble in water, with the ex- 

 ception of the kinate of lead containing 2 atoms of oxide of 

 lead -, alcohol precipitates them from their aqueous solutions. 



Kino'ile is a product of the calcination of a kinate by a gentle 

 heat, and of the action of peroxide of manganese and sulphuric 

 acid upon crystallized kinic acid. It is a remarkable neutral 

 substance, of a golden yellow colour and high lustre, heavier 

 than water, fusing and volatilising without decomposition at 

 212 (Woskresensky). 



SECTION VIII. 

 VOLATILE ACIDS OF BUTTER. 



Butyric acid, HO,C 8 H 5 ^O 3 (Chevreul). This is an oily 

 limpid liquid, having the odour of rancid butter and a nauseous 

 and ethereal taste. Its density is 0.9765 at 77 ; it evaporates 

 easily in the open air, and boils above 212. By distillation 

 butyric acid gives butyrone, C 6 H 6 O (Kraues), the formula of 

 butyric acid being supposed C 7 H 6 O 3 (Loewig). 



Caproic acid, HO-j-C 12 H 9 O 3 (Chevreul), is an oily limpid 

 liquid, having the odour of sweat and a nauseous taste, with a 

 sweetish after-taste of apples. Its density is 0.922 at 71*^ it 

 evaporates in open air, boils above 212, is soluble in 96 parts of 

 water at 44.6. It is miscible with alcohol, ether and oils. 



Capric acid, HO-f C 18 H 14 O 3 (Chevreul), when liquid, greatly 

 resembles caproic acid in physical properties. When agitated 

 at 52.7 it forms a mass of fine needles, which become entirely 

 liquid at 64.4. It has the same odour as caproic acid, with 

 that also of the goat. It is dissolved by alcohol in all propor- 

 tions, and is soluble in 6 parts of water at 68. 



When butter is melted with water, buttermilk, cheese and 



