which presents three distinct species.
1. The hard white granite, with black spots, commonly called moor-stone. It is much used in London, for the steps of public buildings, and on other occasions where great strength and solidity are required.
2. The hard red granite, variegated with black and white, which is common in Egypt and Arabia.
3. The pale whitish granite, diversified with black and yellow. This is sometimes found in strata, but more frequently in loose nodules, and is employed for the paving of streets.
Granites take a good polish; hence the Egyptians formerly employed them, and the Italians still use them for working large pieces of ornamental architecture; a purpose to which this fossil is uncommonly well adapted, as it is not liable to decay in the air. Indeed, there are columns, statues, and other monuments of antiquity erected of granite, and preserved to this day entire, though some of these relics have withstood the test of time for upwards of 4000 years!
GRANULATION, a chemical process, by which metallic substances are reduced to small grains. It consists simply in pouring the melted metal into cold water, from a considerable height. Lead or tin may be granulated, by pouring them when melted into a box, the inner surface of which is to be rubbed with chalk, and the box shaken till the metal becomes cold. The design of granulation is chiefly to facilitate the combination of metals with other substances; because, from their great ductility, they are incapable of being pulverized, and liable to contract impurities from the tedious operation of filing.—See also Lead and Shot.
Granulation is also applied to wheat when divested of its husk, and other surrounding parts, so that the heart or middle of each grain only is preserved entire. In this state, it is called Semolina, and often sold by grocers: it affords an excellent and nutritive food, especially for children and invalids.
GRAPES are the fruit of the Vine, on the culture of which we shall treat under that head.
Grapes are excellent fruit, and well calculated for cleansing the humours, on account of their laxative properties, by promoting the natural evacuations, without debilitating the body. They are, however, remarkably flatulent, and ought to be avoided by those who are liable to eructations, and other complaints arising from bad digestion.—It is asserted, that the small stones of grapes, when swallowed together with the juice in large quantities, have occasioned the most painful and inveterate colics.
Sour grapes ought never to be eaten, as they easily produce gripes, and even the dysentery.
GRASS, in botany, is defined to be a plant or vegetable which has simple leaves, a jointed tubular stem, a husky calyx called gluma, and the seed of which is single.
Grasses are divided into two classes, leguminous and culmiferous. To the former belong wheat, barley, oats, and all other grain, for the various modes of cultivating which, the reader will consult the articles in their alphabetical series.
Culmiferous grasses may likewise be subdivided into two classes, for agricultural purposes; hence it is of importance that every farmer should distinguish, 1. Those which
