PHLOROGLUCIN, ETC. 311 



needles, of a bright leather-color. Very difficultly solu- 

 ble in cold water, more easily soluble in hot water. 



The following substance is isomeric with pyrogallol : 



Phloroglucin, C 6 H 6 3 = C 6 H 3 (OH) 3 . Is produced by 

 heating phloretin, quercetin (see Glucosides), dragon's 

 blood, gamboge, kino, etc. with caustic potassa. 

 Rhombic crystals, with two molecules of water of crys- 

 tallization, of sweet taste. They effloresce in dry air, 

 give up their water at 100, fuse at 220, and sublime 

 almost without decomposition. Easily soluble in water, 

 alcohol, and ether. The aqueous solution turns a deep 

 violet color on the addition of iron chloride. Com- 

 bines with the alkalies, forming deliquescent salts. 



Triacetylphloroglucin, C 6 H 3 (O.C 2 H 3 0) 3 . Small, 

 colorless prisms, but slightly soluble in water. 



Phloramine, OTOTO 2 = C 6 H 3 j ^^ Is formed 



by dissolving phloroglucin in heated aqueous ammonia, 

 and by conducting dry ammonia gas over heated phlo- 

 roglucin. Thin, shiny laminae, resembling mica. But 

 slightly soluble in cold water, easily in alcohol. The 

 solution turns rapidly brown in contact with the air. 

 Well characterized base ; combines with acids, forming 

 crystallizing salts. 



e. Tetratomic Phenols. 



These are as yet unknown, though a few substitu- 

 tion-products of tetroxybenzene, C 6 H 2 (OH) 4 , have been 

 discovered. 



Dichlortetroxybenzene (Hydrochloranilic acid), 

 C 6 C1 2 (OH) 4 . Is produced by the action of nascent 

 hydrogen (sodium-amalgam and hydrochloric acid, tin 

 and hydrochloric acid) on chloranilic acid (p. 302); 

 can be prepared most readily by heating chloranilic 

 acid with a concentrated solution of sulphurous acid 

 at 100. Colorless needles. But slightly soluble in cold 



