peroxide Hydrogen

See Hydrogenii peroxidum. Pocket Formulary.

Carburetted Hydrogen Gas

Light carburetted hydrogen is readily obtained by stirring the mud of stagnant pools. Heavy carburetted hydrogen is prepared by heating 1 part of alcohol with 6 or 7 of oil of vitriol, and conducting the mixed gases through milk of lime, which retains the sulphurous acid; and afterwards through oil of vitriol, which absorbs water, ether, and alcohol. Coal gas is a mixture of these gases, with other hydrocarbons, etc.

Phosphuretted Hydrogen

The spontaneously inflammable variety of this gas is made by boiling phosphorus with solution of potash in a small retort, the beak of which is kept under water: as each bubble of gas rises from the water, it inflames, and forms a ring of white smoke, which dilates as it ascends. The spontaneous inflammability of the gas when mixed with atmospheric air or oxygen renders caution necessary in its preparation. The other varieties of phosphuretted hydrogen have no special interest or application.

Sulphuretted Hydrogen

Hydrosulphuric Acid. Hydric Sulphide. This gas is best obtained from sulphide (sul-phuret) of iron, broken into small lumps. On this compound, contained in a gas bottle, or other suitable apparatus, pour sulphuric acid previously diluted with 7 parts of water. If more acid be afterwards required, dilute the strong acid with only 4 of water. It is absorbed by water.

Nitrogen, or Azote

Atmospheric air may be made to yield an unlimited supply of nitrogen, by exposing it to the action of substances which combine with its oxygen. By burning phosphorus in a large bell-glass standing in water, and allowing it to stand over the water a few hours, nearly pure nitrogen is obtained, which may be further purified by agitating it with solution of pure potash. Corenwinder procures it from his solution of nitrate of potash (which see) by mixing one measure of it with three of concentrated solution of sal ammoniac, and heating the mixture in a flask. The gas contains a little ammonia, from which it may be freed by passing it through diluted sulphuric acid.

Protoxide of Nitrogen

Nitrous Oxide of Davy. It is most conveniently made by heating nitrate of ammonia (formed by neutralizing pure nitric acid, diluted with 3 parts of water, with carbonate of ammonia, and boiling the solution till a drop let fall on a cold plate solidifies, adding a little ammonia towards the end to ensure neutralization) in a retort, at a heat not exceeding 500° Fahrenheit, till it is nearly all decomposed. It may be collected over warm water. This gas (principally, if not wholly, in the liquid form) is manufactured in enormous quantities for the use of dentists and for dental hospitals.

Oxygen Gas

Mix chlorate of potash with a third of its bulk of black oxide of manganese; put the mixture into a gas-bottle, or clean flask, to which a bent tube is fitted by a cork, and apply gentle heat. The gas, which conies over freely, may be collected over water.