Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 2, 1802).djvu/399

G E M a wooden machine, about six fa t in height, in the middle of which •m axis is placed perpendicularly, with six large wings. On these, toe silk i^ wound off the bobbins, by die revolution of the ai> ; and, when it is thus placed round the mill, it is ta en oil" by means of another instrument, and wound on two beams. The silk is then passed through as many small beads as it has threads, and is thus rolled on another beam, in order to supply the loom. Gauzes arc either plain or figur- ed : the latter are worked with flowers of gold and silver, on a silk ground, and are chiefly imported from China. — No >iik gauzes can, during the present hostilities, be imported from either France or Holland: formerly they paid a duty of 21 per cent, on the value of the goods. — Within these icw years, excellent silk and other gauzes were manufactured at Paisley, in Scotland ; but, as this elegant ar- ticle of luxury has lately much declined, the silk is now employed for other more solid purposes. OEM, a general name applied to all precious stones, which are divided into two classes ; 1. The pellucid, or such as are clear, ele- gant and beautiful fossils, extreme- ly hard, and of uncommon lustre ; 2. The semi-pellucid gems, which are found in small detached pieces, and are composed of crystalline matter debased by earth : they are, nevertheless, of great beauty and brightness, and somewhat transpa- rent. The value of gems depends prin- cipally on their hardness and colour. With respect to the former, the diamond is allowed to be the firm- est, and can only be polished, or cut, by its own powder : next to GEN L3 6 7 if, the ruby, sapphire, jacinth, iiner. lid, amethyst, garnet, onyx, jasper, agate, porphyry, and marble. 1 in the order we have enumerated. The same classifica- tion prevails in point of colour : the diamond is universally esteemed on account of its brilliancy; the ruby for its purple j the sapphire for its blue j the emerald for its green ; the jacinth for its orange ; the amethyst for its carnation ; the onyx for its tawney j the jasper, agate, &c. lor their Vermillion, green, and variegated colours; and the garnet for its transparent red. The art of imitating gems is very difficult to be attained ; and, as it can be practised only by those curi- ous persons, who possess both lei- sure and means, we shall not enter into a detail. The same apology will apply to the imitation of what are called antique-gems ; many valu- able impressions of which have been made by Mr. Tassie : hencrf we cannot omit to mention Mr. Raspk's " Account of the Present State and Arrangement of Mr. James Tassib's Collection oj Pastes," bcc. Svo. 1786, where the inquisitive reader v. ill find an interesting subject judiciously treat - ed and explained. GEN E RATION, in physiolog) . implies the propagation of the species, whether in plants, inserts, fishes, or other animals. Having referred the reader to this article, under the head of "Animalcule,'" (vol. i. p. 5/), we are obliged only to explain the term, without entering into specu- lative theories, none of which ha.s hitherto been sanctioned bv genera! authority. Gi: nek Air ox, is also used, in Scripture, for genealogy, or the series of children issued from .1 common