OLEIC ACID. 967 



fied by an alkali. The soap is purified by dissolving it in water 

 and separating it by means of common salt ; these operations 

 being several times repeated. At last, when the soap is colour- 

 less, it is dissolved in water and decomposed by tartaric acid ; 

 the oleic acid thus liberated is washed with boiling water, and 

 dried by the water-bath (Liebig's Traite, ii.). It may be prepared 

 by the same process from the liquid product obtained in the 

 manufacture of stearine candles. The formula for oleic acid 

 established by M. Varrentrapp is C 44 H 39 O 4 . 



Oleic acid forms an oil which is colourless or of a yellowish 

 tint, has a very weak odour, an acrid taste, reddens litmus 

 strongly, is lighter than water, and becomes a mass composed 

 of crystalline needles a few degrees above the freezing point of 

 water. It is insoluble in water, but mixes with alcohol of 

 0.822 in all proportions. Sulphuric acid colours oleic acid. 

 Nitric acid with oleic gives suberic acid, among other products, 

 but no oxalic acid. Peroxide of nitrogen or nitrate of suboxide 

 of mercury transforms oleic acid into elaidic acid. 



Oleates. Oleic acid decomposes the alkaline carbonates ; its 

 compounds are soft, have the appearance of soap and dissolve 

 better in alcohol than in water. Oleine, the oleate of oxide of 

 glyceryl, forms the greater portion of the fat oils and of most 

 of the solid fats found in nature. It is mixed in these with 

 margarine or stearine, either of which is deposited in the solid 

 state, when the oil is exposed to great cold, the oleine may then 

 be separated by expression of the solid matter, although never 

 in a state of purity. According to Pelouze and Boudet there 

 are two species of oleine, the liquid portion of such fats as are 

 not drying but disposed to become rancid, differing from the 

 liquid portion of the drying oils, in solubility, and particularly 

 in the transformation which it undergoes under the influence 

 of hyponitric acid into elaidine and elaidic acid, while the 

 oleine of drying oils undergoes no sensible alteration in the 

 same circumstances. The neutral oleate of potash is deli- 

 quescent in a damp atmosphere, dissolves completely in 4 parts 

 of water, forming a viscid syrup, and is decomposed by a 

 greater excess of water and resolved into potash and an 

 acid oleate of potash. The latter salt is insoluble in water, 

 but dissolves easily in hot or cold alcohol. Oleate of soda dis- 

 solves in 1 parts of water at 89.G. Oleate of lead is soluble in 

 ether. 



