The Hydroidea.

An instrument used for the purpose of obtaining specimens of water from any desired depth, as in a river, a lake, or the ocean.

One of the flat, leaflike, protective zooids, covering other zooids of certain Siphonophora.

An aquatic plant; an alga.

The branch of botany which treats of water plants.

Dropsical, or resembling dropsy.

In a hydropical manner.

A species (Polygonum Hydropiper) of knotweed with acrid foliage; water pepper; smartweed.

Of a boat, to move through water while supported by hydroplanes{3} (see hydroplane{3}, above).

Pertaining to, or depending upon, both liquid and gaseous substances; as, hydropneumatic apparatus for collecting gases over water or other liquids.

Same as Dropsy.

A machine for throwing water by hand power, as a garden engine, a fire extinguisher, etc.

A white crystalline substance, C6H4(OH)2, obtained by the reduction of quinone. It is a diacid phenol, resembling, and metameric with, pyrocatechin and resorcin. Called also dihydroxy benzene.

The rootstock or decumbent stem by which a hydroid is attached to other objects. See Illust. under Hydroidea.

A salt supposed to be formed by a hydracid and a base. An acid salt. A hydrous salt; a salt combined with water of hydration or crystallization.

An instrument designed to mark the presence of water, especially in air.

All the zooids of a hydroid colony collectively, including the nutritive and reproductive zooids, and often other kinds.

Pertaining to, or designating, an acid obtained from sorbic acid when this takes up hydrogen; as, hydrosorbic acid.

The aqueous vapor of the entire atmosphere.

A contrivance or apparatus to prevent the explosion of steam boilers.

Of or relating to hydrostatics; pertaining to, or in accordance with, the principles of the equilibrium of fluids.

According to hydrostatics, or to hydrostatic principles.

One who is versed or skilled in hydrostatics.

The branch of science which relates to the pressure and equilibrium of nonelastic fluids, as water, mercury, etc.; the principles of statics applied to water and other liquids.

Same as Hydrosulphurent.

One of a series of compounds, derived from hydrogen sulphide by the replacement of half its hydrogen by a base or basic radical; as, potassium hydrosulphide, KSH. The hydrosulphides are analogous to the hydrates and include the mercaptans.

A saline compound of hydrosulphurous acid and a base.

A hydrosulphide.

Combined with hydrogen sulphide.

Pertaining to, or derived from, hydrogen and sulphur; as, hydrosulphuric acid, a designation applied to the solution of hydrogen sulphide in water.

Pertaining to, or designating, an acid obtained by the reduction of sulphurous acid. See Hyposulphurous acid, under Hyposulphurous.

A salt formed by the union of hydrotelluric acid and the base.

Formed by hydrogen and tellurium; as, hydrotelluric acid, or hydrogen telluride.

One of the calicles which, in some Hydroidea (Thecaphora), protect the hydrants. See Illust. of Hydroidea, and Campanularian.

A system of treating disease by baths and mineral waters.

See Hydropathy.

Of or pertaining to hot water; -- used esp. with reference to the action of heated waters in dissolving, redepositing, and otherwise producing mineral changes within the crust of the globe.

An accumulation of serous fluid in the cavity of the chest.

Causing a discharge of water or phlegm. A hydrotic medicine.

Hydrotic.

A device for raising water by the direct action of steam; a pulsometer.

Turning or bending towards moisture, as roots.

A tendency towards moisture.

Containing water; watery.

A persulphocyanate.

Persulphocyanic.

A hydrate; a substance containing hydrogen and oxygen, made by combining water with an oxide, and yielding water by elimination. The hydroxides are regarded as compounds of hydroxyl, united usually with basic element or radical; as, calcium hydroxide ethyl hydroxide.

A compound radical, or unsaturated group, HO, consisting of one atom of hydrogen and one of oxygen. It is a characteristic part of the hydrates, the alcohols, the oxygen acids, etc.

A nitrogenous, organic base, NH2.OH, resembling ammonia, and produced by a modified reduction of nitric acid. It is usually obtained as a volatile, unstable solution in water. It acts as a strong reducing agent.

a methyl radical with a hydroxyl group replacing one of the hydrogen atoms.

A crystalline amino acid (C5H9NO3), a hydroxylated proline, obtained by hydrolysis of gelatin or collagen. Chemically it is 4-hydroxy-L-proline. It is classified as nonessential for growth in rats.

The Acaleph/; one of the classes of c/lenterates, including the Hydroidea, Discophora, and Siphonophora.

Of or pertaining to the Hydrozoa.

One of the Hydrozoa.

A binary compound of hydrogen; a hydride.

A constellation of the southern hemisphere, near the south pole.

See Hie.

Belonging to winter; done in winter.

To pass the winter.

The passing of a winter in a particular place; a wintering.

Any carnivorous mammal of the family Hy/nid/, doglike nocturnal mammals of Africa and southern Asia, of which three living species are known. They are large and strong, but cowardly. They feed chiefly on carrion, and are nocturnal in their habits.

Of or pertaining to rain; descriptive of the distribution of rain, or of rainy regions.

A chart or graphic representation of the average distribution of rain over the surface of the earth.

Of or pertaining to to hyetography.

The branch of physical science which treats of the geographical distribution of rain.

The science which treats of the precipitation of rain, snow, etc.

The goddess of health, daughter of Esculapius.

Relating to Hygeia, the goddess of health; of or pertaining to health, or its preservation.

One skilled in hygiena; a hygienist.

A hygienist.

That department of sanitary science which treats of the preservation of health, esp. of households and communities; a system of principles or rules designated for the promotion of health.

Of or pertaining to health or hygiene; sanitary.

The science of health; hygiene.

Hygiene.

One versed in hygiene.

A treatise on, or the science of, the preservation of health.

An alkaloid associated with cocaine in coca leaves (Erythroxylon coca), and extracted as a thick, yellow oil, having a pungent taste and odor.

A form of hygrometer having wet and dry bulb thermometers, with an adjustable index showing directly the percentage of moisture in the air, etc.

An instrument for recording automatically the variations of the humidity of the atmosphere.

The science which treats of the fluids of the body.

An instrument for measuring the degree of moisture of the atmosphere.

Of or pertaining to hygrometry; made with, or according to, the hygrometer; as, hygrometric observations.

That branch of physics which relates to the determination of the humidity of bodies, particularly of the atmosphere, with the theory and use of the instruments constructed for this purpose.

Having such a structure as to be diaphanous when moist, and opaque when dry.

Serving to moisten the eye; -- sometimes applied to the lachrymal ducts.

The fluid portion of the cell protoplasm, in opposition to stereoplasm, the solid or insoluble portion. The latter is supposed to be partly nutritive and partly composed of idioplasm.

An instrument which shows whether there is more or less moisture in the atmosphere, without indicating its amount.

Of or pertaining to, or indicated by, the hygroscope; not readily manifest to the senses, but capable of detection by the hygroscope; as, glass is often covered with a film of hygroscopic moisture.

The property possessed by vegetable tissues of absorbing or discharging moisture according to circumstances.

The science or art of comparing or measuring degrees of moisture.

See Haik, and Huke.

A dynasty of Egyptian kings, often called the Shepherd kings, of foreign origin, who, according to the narrative of Manetho, ruled for about 500 years, forming the XVth and XVIth dynasties. It is now considered that the XVIth is merely a double of the XVth dynasty, and that the total period of the six Hyksos kings was little more than 100 years. It is supposed that they were Asiatic Semites.

A large Wealden dinosaur from the Tilgate Forest, England. It was about twenty feet long, protected by bony plates in the skin, and armed with spines.

Presiding over matter.

Same as Hyl/osaur.

Of or pertaining to matter; material; corporeal; as, hylic influences.

A philosopher who treats chiefly of matter; one who adopts or teaches hylism.

A theory which regards matter as the original principle of evil.

Any species of the genus Hylobates; a gibbon, or long-armed ape. See Gibbon.

The piping frog (Hyla Pickeringii), a small American tree frog, which in early spring, while breeding in swamps and ditches, sings with high, shrill, but musical, notes.

Same as Hylotheism.

Same as Hylotheist.

The doctrine that matter is sentient.

One who believes in hylopathism.

Eating green shoots, as certain insects do.

The doctrine of belief that matter is God, or that there is no God except matter and the universe; pantheism. See Materialism.

One who believes in hylotheism.

Of or pertaining to hylozoism.

The doctrine that matter possesses a species of life and sensation, or that matter and life are inseparable.

A believer in hylozoism.

The wild ass of Persia.

A fabulous deity; according to some, the son of Apollo and Urania, according to others, of Bacchus and Venus. He was the god of marriage, and presided over nuptial solemnities.

Same as hymeneal.

A marriage song.

The spore-bearing surface of certain fungi, as that on the gills of a mushroom.

An order of fungi sometimes placed in subclass Homobasidiomycetes.

The production of artificial membranes by contact of two fluids, as albumin and fat, by which the globules of the latter are surrounded by a thin film of the former.

One of the great divisions of fungi, containing those species in which the hymenium is completely exposed.

That part of a fungus which is covered with the hymenium.

One of the Hymenoptera.