Hydrogen

(hif -dro-jen). H I. Quanti valence I. A gaseous element, one liter of which weighs.0896 gram. It is feebly basic and occurs in nature combined with oxygen in the form of water It has been liquefied at a temperature of 2860 F. under a tension of 650 atmospheres a pre ure of about 4.7 tons per square inch. In combination with carbon, oxygen, and nitrogen, it forms a multitude of radicles formerly known as " organic" compounds, but now often synthetically formed. It is used largely in the qualitative determination of arsenic and antimony, and for combustion with oxygen to produce intense heat. It has also been used by inhalation in pulmonary tuberculosis. See Elements, Table of. H. peroxid, or dioxid, an unstable compound having the composition It is a powerful antiseptic and germicide, and is used as a disinfectant in diphtheria, glandular swellings and suppurative inflammations, and as an antispasmodic to relieve the paroxysms of whooping cough. It is the basis of most hair-bleaching solutions. Dose Unof. H. d., Aqua, solution of hydrogen dioxid; contains 3 per cent, by weight of the pure dioxid. H. sulphid. See Acid Hydrosulphuric. Hydro genesis (hi-dro-jen' '-es-is).