968 OILY ACIDS. 



cording to Bromeis, cenanthylic acid is identical with the azoleic 

 acid of Laurent. 



Castor oil solidifies with nitrate of suboxide of mercury, or 

 with peroxide of nitrogen, and forms a yellow transparent mass 

 like wax. The mass washed with water and dissolved in boil- 

 ing alcohol furnishes palmine in confused crystalline grains. 

 Alkalies saponify palmine like ela'idine, disengaging glycerin, 

 and combining with palmic acid. This acid, when pure, crys- 

 tallizes in white silky needles, grouped about a common centre, 

 is fusible at 122, and dissolves with facility in alcohol and ether. 

 Palmine and palmic acid are also formed by the action of 

 sulphurous acid gas on castor oil. 



ACIDS FORMED BY THE ACTION OF SULPHURIC ACID ON THE 



FAT GILS. 



When sulphuric acid is added in small proportion to fat oils, 

 its action is limited to the abstraction of their glycerin, with 

 which it combines and forms sulphoglyceric acid (page 878), 

 while the oily acids are set at liberty. Such is the reaction that 

 occurs when tallow or hog's lard is mixed with half its weight 

 of sulphuric acid. But when the proportion of sulphuric acid 

 is increased, particular compounds of that acid with the oily 

 acids are produced, which dissolve in water. The compounds 

 thus formed by acting upon olive oil with concentrated sulphuric 

 acid have been carefully studied by M. Fremy.* 



Oleic acid and concentrated sulphuric acid combine directly, 

 and form sulpholeic acid, a double acid. Pure margaric acid 

 dissolves in sulphuric acid, but does not form a stable com- 

 pound, for it is separated by water without having undergone 

 any alteration ; but when mixed with a certain quantity of oleic 

 acid, both oily acids combine with sulphuric acid, and su/pho- 

 margaric acid is formed with sulpholeic acid. These two com- 

 pounds are equally formed, together with sulphate of glycerin, 

 when half a volume of concentrated sulphuric acid is cautiously 

 added by small quantities, to olive oil, any elevation of tempe- 

 rature being guarded against. If then mixed with twice its 



* Ann. de Chim. et de Phys. t. Ixv, p. 113. 



