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do group, or with a monamine; hence, also, a derivative of ammonia, in which two atoms of hydrogen have been replaced by divalent basic or acid radicals; -- frequently used as a combining form; as, succinimide.

ne or more acid radicals so united with the imido group that it contains replaceable acid hydrogen, and plays the part of an acid; as, uric acid, succinimide, etc., are imido acids.

by pressure; -- said of any gas above its critical point; -- also particularly of oxygen, hydrogen, nitrogen, and carbon monoxide, formerly regarded as incapable of liquefaction at any temperature or pressure.

e; easily provoked; as, an inflammable temper. Inflammable air, the old chemical name for hydrogen.

Iodic acid, a monobasic acid, consisting of iodine with three parts of oxygen and one of hydrogen.

ratus for the instantaneous production of a flame by the spontaneous ignition of a jet of hydrogen on being led over platinum sponge; -- named after the German chemist Döbereiner, who invented it. Called also philosopher's lamp. -- Flameless lamp, an aphlogistic lamp. -- Lamp burner, the part of a lamp where the wick…

educing a gas or vapor to a liquid by cold or pressure; as, the liquefaction of oxygen or hydrogen.

A compound of mercaptan formed by replacing its sulphur hydrogen by a metal; as, potassium mercaptide, C2H5SK.

cal regarded as derived from ammonium by the substitution of mercury for a portion of the hydrogen.

othetical radical derived from ammonium by the substitution of metallic atoms in place of hydrogen.

eplacement of atoms and radicals; thus, by metathesis an acid gives up all or part of its hydrogen, takes on an equivalent amount of a metal or base, and forms a salt.

herring brine and other fishy products. It is regarded as ammonia in which a third of its hydrogen is replaced by methyl, and is a type of the class of substituted ammonias. -- Methyl ether (Chem.), a light, volatile ether CH3.O.CH3, obtained by the etherification of methyl alcohol; -- called also methyl oxide. -- Me…

An alcoholate of methyl alcohol in which the hydroxyl hydrogen is replaced by a metal, after the analogy of a hydrate; as, sodium methylate, CH3ONa.

The weight of the half hydrogen molecule, or of the hydrogen atom, taken as the standard in comparing the atomic weights of the elements; thus, an atom of oxygen weighs sixteen microcriths. See Crith. J. P. Cooke.

(called the objective) is magnified by another lens called the ocular or eyepiece. -- Oxyhydrogen microscope, and Solar microscope. See under Oxyhydrogen, and Solar. -- Simple, or Single, microscope, a single convex lens used to magnify objects placed in its focus.

lecular weight (Chem.), the weight of a molecule of any gas or vapor as compared with the hydrogen atom as a standard; the sum of the atomic weights of the constituents of a molecule; thus, the molecular weight of water (H2O) is 18.

compound that can exist in a free state; as, a molecule of water consists of two atoms of hydrogen and one of oxygen. Cf. Atom.

Having one hydrogen atom replaceable by a negative or acid atom or radical; capable of neutralizing a monobasic acid; -- said of bases, and of certain metals.

valence is one, or which can combine with, be replaced by, or exchanged for, one atom of hydrogen. Monad deme (Biol.), in tectology, a unit of the first order of individuality.

Having the equivalence or replacing power of an atom of hydrogen; univalent; as, the methyl radical is monatomic.