Heated to about 140 Fehr., grape-sugar softens, and at 212° Fehr. melts, and loses two equivalents of water. At a higher temperature it is converted into caramel. Water dissolves less of grape than of cane. Sugar, the solution is less viscid, and it is not so sweet ; hot alcohol, however, dissolves more of it, but it is deposited again on cooling in crystalline grains. With sulphuric acid, instead of being charred, as cane-sugar is, it forms a compound ncid called sulphosaccharic add, sulpholignie, xTgeta-sulphuric, or sulphamidonic acid, which gives no precipitate with the salts of barium.
Honey contains both fructose, or uncrystallisable sugar, and glucose. sugar. The two may be separated by strong alcohol, which dissolve: the fructose and leaves the grape-sugar behind.
Manna Sugar. [31assivs.] Hashreera Sugar. [31.arcstra] Liguorice Sugar, so-called, is not a true sugar. See GLYCYI111111.7.1N. Sugar of .11 ilk, Lactine, or Lactose (C„H„0„), is obtained by evapo rating the whey of milk to its crystallising point ; it forms colourlee four-sided prisms, which are soluble in about six parts of cold water and two and a half parts of hot : the taste of this sugar is not very sweet, it is unalterable in the air, and is insoluble in alcohol and ether, Boiled with dilute acids, it is slowly converted into glucose. It form
two insoluble compounds with oxide of lead; and reduces boiling solu tions of salts of copper, mercury, or silver.
Afditose, trelatlose, and melezitosc, are three varieties of sugar lately discovered by 31. Berthelot. They are closely allied to cane-sugar 3Iclite,e is contained in Australian manna, a product of the Ettea/ga by fermentation it yields a non-crystalline body, termed Eucalyz (C,,11,,O,,,2H0). Trchalose, is contained in Turkish manna, a stance formed by an insect (Larimus nidificans) at the expense of i plant of the genus .Echinops ; it seems to be identical with the mycoso of 3litacherlich, a sweet principle contained in ergot of rye. Nefesites occurs in Briancon manna, an exudation front the larch tree.
Serbin (C„ is a sugar contained in the benies of the mountain ash (Sorlau ancuparie). pleat transforms it into a deep red matter, termed sortfinie add.