206 THE CONSTITUENTS OF PLANTS. IX. 



yield monovalent alcohols on treatment with alkalies. The 

 alcohols obtained in this way are usually complex bodies con- 

 taining a large number of carbon atoms, e.g., ceryl alcohol, 

 C 27 H 5(} 0.(?). The waxes are solids melting below 100, non- 

 volatile, and insoluble in water, but soluble in ether. 



Possessing a structure in some respects similar to the fats is 

 a substance, Lecithin, found in many seeds, e.g., beans and 

 peas, and in fungi. This substance, of which probably several 

 varieties occur, has a constitution which may be typified by 

 the following formula : 



(C 1H H,A 

 C 3 H 5 j C^HaA 



IHPO 4 .C 2 H 4 (OH).N(CH 3 ) 3 



which may be regarded as the distearyl glycerophosphate of 

 the base, choline, C 2 H 4 (OH).N(CH 3 ) 3 .OH. 



Phytosterol, C 2G H 43 OH, which closely resembles cholesterol 

 found in animals, occurs in the seeds of peas, beans, and 

 almonds, in wheat, maize, and in many vegetable oils. It is 

 a solid crystalline substance melting at 133 and soluble in 

 hot alcohol, in ether, carbon disulphide, or chloroform. It is 

 volatile. Its constitution is not understood, but it probably is 

 a monacid alcohol. 



III. THE OKGANIC ACIDS AND THEIR SALTS. 



A large number of organic acids have been detected in 

 various vegetable products, occurring generally as potassium, 

 sodium, or calcium salts, though sometimes in the free state or 

 in combination with organic bases. Numerous acids have 

 been detected in various vegetables ; only a few typical ones 

 can be considered here. The organic acids are characterised 

 by containing one or more " carboxyl " groups, i.e., .COOH. 

 The following may be taken as examples : 



Formic acid, H.COOH. 



Oxalic acid, COOH.COOH. 



Tartaric acid, COOH.CH(OH).CH(OH).COOH. 



Malic acid, COOH.CH(OH).CH 2 .COOH. 



Citric acid, CH 2 (COOH).C(OH)(COOH).CH 2 (COOH). 



Succinic acid, CH 2 (COOH).CH 2 (COOH). 



Fumaric acid, CH(COOH):CH(COOH). 



