SUGAR, PROPERTIES OK Sugar is a proximate principle, chiefly of vegetables, but also sparingly of animals of the class Mani Melia. It presents considerable varieties, according to the source whence it is obtained, and is distinguished into those which are ble of undergoing the vinous fermentation, and into these which are not ; also into those which can assume a definite crystalline form, and those which cannot ; but sometimes these two kinds co-exist in the same sort, as in the sugar from the sugar cane, which yields both the finest crystals and likewise molasses or treacle. It almost invariably exists in a dilute and liquid state in plants, but it occasionally exhibits a crystalline form in the flower of certain plants, such as the Rhododen dron ponticum, the Strelitzia Regina, and Euconzis punctata. Sugar is the great principle by which rapidly-growing succulent parts of plants and seeds, when they germinate, are nourished. Hence it is produced in large quantities in such seeds as contain starch, when excited to germinate, as may be observed in the process of malting, which up to a certain stage is exactly that of the germination of the seed. Under these circumstances, seeds which are insipid from the bland nature of the starch which they contain become sweet. By this means many seeds which are regarded as little suited for the nourishment of man may be made to contribute to his support, by merely steeping them in water till they sprout. A similar transformation of starch into sugar takes place in the ripening of many fruits. Thus the fruit of the banana, or plaintain, which, when gathered green, abounds in starch, if allowed to ripen on the stalk is destitute of starch, and yields much gummy and saccharine matters. The same happens when the palms arc about to flower, as all the starch in their lofty stems is rapidly transformed into sugar ; and hence the sago-palm (Sagas Rumphii, ate.) and the .1Iauritia ilexuosa (sago-palm of the Orinoco) are cut down just when the flower-buds begin to appear, to obtain the sago they contain. In other palms the flower-buds are allowed to protrude, and
a wound being made in the spatha, a large quantity of a sweet fluid distils, which may either be concentrated by boiling, when sugar is deposited, or the liquid may he fermented, and so yield the toddy called palm. wine. If these or the sugar-cane, maize, or our common esculent roots, paranep, skirret, carrot, or beet, are allowed to flower, all the gummy and saccharine matters disappear from the roots or stem. The transformation of starch into gum and sugar is effected by a principle called diastase [FsuaiErr], which is so powerful, that "one part of it is sufficient to render soluble the interior portion of two thousand parts of etarch, and convert it into sugar." Wherever buds are lodged, there the elements of diastase are placed, to come into play, when they begin to sprout, and supply them with food in a state of solution, as is the case with the buds or eyes of potatoes.
Many seeds, before they are ripe, contain a saccharine substance, which is changed into starch when fully ripe, but which again becomes sugar in germinating, such as the garden pea. Many stems of grasses are sweet at an early stage of their growth, but become insipid at a later period. This influences greatly the nutritive powers of these grasses, according to the stage of growth when they are cut down and made into hay. (See appendix to Davy's Agricultural Chemistry.') Those which have been allowed to become too ripe are often (restored to a proper state by the fermentation (heating) which occurs after the hay is stacked; but this is sometimes so violent as to consume the rick.
The starch lodged in the stem of certain trees in autumn is con verted, by the ascending sap in spring, into sugar, with great rapidity. This is the case with the deer saecharinum, or sugar-maple, and many other species of that genus which are tapped in February.