PHLORETIC ACID, ETC. 353 



(OH 



2. Phloretic acid, C 6 H 2 ](CH 3 ) 2 Is formed, 



( CO.OH. 



together with phloroglucin (p. 311), by evaporating 

 phloretiii with potassa-ley. Potassium phloretate is 

 extracted from the residue by means of alcohol, pre 

 cipitated from this solution by ether, and after dis 

 solving in water, decomposed by hydrochloric acid. 

 Long, brittle, colorless prisms, difficultly soluble in 

 cold water, easily soluble in hot water and in alcohol. 

 Fuses at 128-130, and when heated with baryta, is 

 decomposed into carbonic anhydride and phlorol (p. 

 300). Its solution is colored green by iron chloride. 



(OH 

 3 Alorcic acid, C 6 H 2 -I (CH 3 ) 2 In small quantity, 



( CO.OH. 



together with orciii and paraoxybenzoic acid, in the 

 preparation of orcin from aloes. Fine, brittle needles; 

 difficultly soluble in cold water, easily in boiling 

 water, in alcohol and ether. Fusing caustic potassa 

 converts it into orcin and acetic acid. 



4. Melilotic acid (Hydrocoumaric acid), 



6H4 1 CH 2 CH 2 CO OH Is contained in common meli - 

 lot (Melilotus officinalis), in the leaves of Faham, some 

 times in combination with coumarin, sometimes free^ 

 and is produced by treating an aqueous solution of 

 coumarin with sodium-amalgam. Large, colorless, lan- 

 ceolar crystals. Very easily soluble in hot water, 

 alcohol, and ether, moderately easily in cold water (in 

 20 parts of 18). Fuses at 82. Its solution is colored 

 bluish for the moment by iron chloride. Heated alone 

 it is resolved into water and its anhydride, C 9 H 8 2 , a 

 substance that crystallizes in rhombic plates, fuses at 

 25, and boils at 272. Fusing potassium hydroxide 

 decomposes it, yielding acetic and salicylic acids, the 

 action being accompanied by an evolution of hydro 

 gen. its salts, when carefully heated, yield the anhy 

 dride, when more strongly heated, phenol. 



30* 



