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A white crystalline hydrocarbon C

A colorless, crystalline hydrocarbon, C13H10 having a beautiful violet fluorescence; whence its name. It occurs in the higher boiling products of coal tar, and is obtained artificially.

omposed of, or derived from, silicon and fluorine. Fluosilicic acid, a double fluoride of hydrogen and silicon, H2F6Si, obtained in solution in water as a sour fuming liquid, and regarded as the type of the fluosilicates; -- called also silicofluoric acid, and hydrofluosilicic acid.

A compact form of hydro-aëroplane having one central body, or hull.

A Linnæan genus of hymenopterous insects, including the common ants. See Ant.

A group of hymenopterous insects including the sand wasps. They excavate cells in earth, where they deposit their eggs, with the bodies of other insects for the food of the young when hatched. [Written also Fossoria.]

The act of rubbing the surface of one body against that of another; attrition; in hygiene, the act of rubbing the body with the hand, with flannel, or with a brush etc., to excite the skin to healthy action.

A European plant (Hydrocharis Morsus-ranæ), floating on still water and propagating itself by runners. It has roundish leaves and small white flowers.

tation and cause it to turn black, without the formation of hoarfrost. -- Frost bearer (Physics), a philosophical instrument illustrating the freezing of water in a vacuum; a cryophous. -- Frost grape (Bot.), an American grape, with very small, acid berries. -- Frost lamp, a lamp placed below the oil tube of an Arga…

resembling cantharides, but when dissolved forming a brilliant dark red. It consists of a hydrochloride or acetate of rosaniline. See Rosaniline.

rms or insects; esp., the apparatus used to destroy San José scale on nursery stock, with hydrocyanic acid vapor.

Pertaining to hypogeic acid; -- applied to an acid obtained from hypogeic acid.

on any part of a plant by insects or their larvae. They are most commonly caused by small Hymenoptera and Diptera which puncture the bark and lay their eggs in the wounds. The larvae live within the galls. Some galls are due to aphids, mites, etc. See Gallnut.

An insect that deposits its eggs in plants, and occasions galls, esp. any small hymenopteran of the genus Cynips and allied genera. See Illust. of Gall.

An amorphous mineral of apple-green color; a hydrous silicate of nickel and magnesia. It is an important ore of nickel.

s with air, but since restricted to fluids supposed to be permanently elastic, as oxygen, hydrogen, etc., in distinction from vapors, as steam, which become liquid on a reduction of temperature. In present usage, since all of the supposed permanent gases have been liquified by cold and pressure, the term has resumed ne…

A volatile hydrocarbon, used as an illuminant, or for charging illuminating gas.

A highly volatile mixture of fluid hydrocarbons, obtained from petroleum, as also by the distillation of bituminous coal. It is used in making air gas, and in giving illuminating power to water gas. See Carburetor.

A primeval larval form; a double-walled sac from which, according to the hypothesis of Haeckel, man and all other animals, that in the first stages of their individual evolution pass through a two-layered structural stage, or gastrula form, must have descended. This idea constitutes the Gastræa theory of Haeckel. See G…

pertaining to, or situated near, the stomach; as, the gastric artery. Gastric digestion (Physiol.), the conversion of the albuminous portion of food in the stomach into soluble and diffusible products by the solvent action of gastric juice. -- Gastric fever (Med.), a fever attended with prominent gastric symptoms; --…