DULCITE. 189 



dride. White, granular, crystalline mass, but slightly 

 soluble in cold water, more easily in hot water and in 

 alcohol. F^ses at about 100. 



Mannitan, C 6 H 12 5 , is formed from mannite by 

 heating to 200, and by continued boiling with con 

 centrated hydrochloric acid. Sweet tasting syrup, 

 easily soluble in water and alcohol, insoluble in ether. 

 Is reconverted into mannite, slowly in moist air, 

 rapidly by boiling with barium hydroxide. Ethers of 

 mannitan are formed by heating mannite with organic 

 acids. 



Several bodies, which are isomeric with mannitan, 

 occur in nature. 



ftuercite, C 6 H 12 5 . In acorns. Colorless, mono- 

 clinic crystals of a sweet taste ; fusing point, 235. 



Finite, C 6 II 12 5 . In the sap of the California pine 

 (Pinus lambertiand). Colorless, nodular crystals, easily 

 soluble in wafer. 



Isodulcite, C 6 H 12 5 + H 2 0. By decomposition of 

 quercitrine (see Glucosides) with dilute sulphuric acid. 

 Large, colorless, transparent crystals, easily soluble 

 in water. Fuses at 105-110, at the same time losing 

 its water of crystallization. 



Hesperidine sugar, C 6 II 12 5 + H 2 0. By the de 

 composition of hesperidine. Colorless, easily soluble 

 crystals. Fuses at 71-76, and loses its water at 100. 



2. Dulcite (Melampyrin\ 



C 6 H 1 4 Q6 = C 6 H 8 (OII) 6 . 



Occurrence. In Melampyrum nemorosum, Scrophu- 

 laria nodosa, Ehinanthus Christa Galli, Evonymus 

 Europwus, and other plants. In the largest quantity 

 in dulcite-rnanna, a variety of manna of unknown 

 origin, coming from Madagascar. 



