Lactine, or Lactose (Fn., Diehet d,e tail ; GER., Schottensand, Zatekersand).— This is obtained from milk by precipitating the casein with a few drops of dilute sulphurie sad, and filtering and evaporating the liquid. Crystals are deposited, which are purified by re-dissolving and treating with animal charcoal. In Switzerland, considerable quantities of milk-sugar are prepared by evaporating the whey which remains after the separation of the cheese. At Marbach, Canton of Lucerne, Switzerland, half-a-dozen refiners are said to make a handsome income from the manu facture of rnilk-sugar. The raw material used for the recrystallization comes from the neighbouring Alps, in the cantons of Lucerne, Berne, Schwyz, &c. ; a considerable quantity is supplied also by Gruyeres. Notwithstanding rises in the price of the raw material, consequent upon the demand, and increased cost of labour and fuel, the manufacture continually expands, and now amounts to 1800-2000 cwts. yearly, with a gross value of about 12,500/. The manufacture of tbe crude sugar is only carried on in the higher mountains, because there the whey cannot be used profitably for fattening swine, which are found chiefly in the valleys; and the wood required for tbe evaporating process iB cheaper in the highlands.
The crude sugar is sent to the manufacturer or refiner in sacks containing 1-2 cwts. It is washed in copper vessels, and dissolved to saturation at the boiling temperature over a fire ; the yellow-brown liquor, after straining, is allowed to stand in copper-lined tubs or long troughs to crystallize. The sugar-crystals form in clusters on immersed chips of wood ; these are the rnost pure, and therefore of rather greater commercial value than the milk-sugar in " plates," which is deposited on the sides of the vessels. In 10-14 days, the crystallization is complete, and the milk sugar has finished growing. The crystals are then washed with cold wat,er, afterwards dried in a caldron over a fire, and packed in casks bolding 4-5 cwts. As the crude sugar can only be obtained in summer, the recrystallization is not carried on in winter. The entire manipulation is carried on in a very primitive naanner : with a more rational method of working, a whiter and finer quality of sugar could probably be produced. Milk-sugar finds its chief application as a basis for homceopathic medicines, and in infants' foods.
Palm-sugar.—Palm-sugar, often called date-tree sugar, is a product of the juices of many kinds of palm, the most important being the wild date-palm (Phanix kylvestris), which thus gives a name t,o the whole class. Other species are the palmyra (Borassus flabelliformis), (see p. 932); the coco-nut (Cocos nucifera), (see pp. 939, 1353, 1383); the gomuti (Saguerus [Arenga)saccharifera), (see pp. 919, 1827); the nipa (Nipa fruticans), (see p. 985); and the kittool (Caryota urens), (see p. 938). All these are essentially natives of the E. Indies, including India, Ceylon, Siam, the Maley
Peninsula, and the E. Archipelago.
The portion of British India particularly occupied by this cultivation extends nearly due E. and W. from Kissengunge, in Kishnagur, to a little beyond Nollchit in the Backergunge district ; and N. and S., from the vicinity of Comercolly in the Pubna district, to the borders of the Sunderbunds, thus occupying on the map a surfae,e of about 130 miles long by 80 broad. Its principal districts are Jessore, Furreedpore, and Backergunge, with portions of Nuddeab, Barastt and Pubna; beyond this tract, little or no date-tree sugar is manufactured, although the tree is often cultivated in other districts, and may be occasionally met with in most parts of India.
Here one species only, Phanix sylvestris, is availed of, though many others might be profitably utilized. From Cocos nucifera, good goor is commonly made in Province Wellesley ; and from Borassus flabelliformis, throughout Bengal, a saccharine juice is obtained, used for intoxicating purposes (see Beverages—Toddy, pp. 425-6), frequently as a substitute for yeast in making bread, and is said by the natives to yield a sugar of good grain and greyish complexion.
The sugar obtained by the natives of Bengal and Siam from the various species of palm is, on account of the crude way in which it is manufactured, of very inferior quality, aud is mainly con sumed in the countries where it is grown. The juie,e of the nipa palm (Nipa fruticans) is almost equal in saccharine richness to that extracted from the sugar-cane, with the advantage that it is much cleaner, and e,ontains no colouring matter nor chlorophyll ; the vegetable matter being easily precipitated, it gives a liquor as clear as spring-wat,er. This species, flourishing near the sea, or on the edges of brackish pools, takes up a large quantity of salt, which makes its appearance in the juice, in quantity sufficient, in some cases, to give the liquor a decidedly saline taste. Were it not for this drawback, a large quantity of excellent sugar would be obtained from this source.
The date-palm (Pbxnix sylvestris) requires a humid soil and climate, and flourishes best in the vicinity of water, tlaough it must be above the reach of annual inundations from the rivers. The trees are planted by the natives mostly in the hedges surrounding the fields appropriated to rice aud other grain. Where regular plantations have been attempted, the trees are placed 10-15 ft. apart, so that sufficient space is left for cultivating an oil-seed or other dry crop between them, without its being injured by the shade of their leaves ; indigo is said to be the only crop which suffers through not obtaining the full benefit of the sun's rays.