4060. Protoxide of Nitrogen

4060.    Protoxide of Nitrogen. This gas is also called nitrous oxide, and is largely used by inhalation, under the name of laughing gas, to produce insensibility to pain. It is colorless, possesses an agreeable odor, and a sweetish taste. At 45° Fahr., and under a pressure of 50 atmospheres, it is liquid. Its specific gravity is 1.5241; it supports combusGAS.

tion, and is absorbed by water. Its most remarkable property is its action on the system when inspired. A few deep inspirations are usually succeeded by a pleasing state of excitement, and a strong propensity to laughter and muscular exertion, which soon subside, without being followed by languor or depression. Its effects, however, vary with different constitutions.

4061. To Prepare Laughing Gas

4061.     To Prepare Laughing Gas. Evaporate a solution of nitrate of ammonia until a drop of the fused mass placed on a cold plate instantly solidifies; cool, break the lump into pieces, and place it in a stoppered bottle. For use, a portion is introduced into a glass retort, and heat applied by means of a spirit lamp. As soon as the heat reaches 480° Fahr., protoxide of nitrogen is evolved, and may bo collected in bladders, gas bags, a gasometer, or in the pneumatic trough over warm water. (See No. 4031 (Pneumatic Trough).) Should white fumes appear within the retort after the evolution of the gas has commenced, the heat should be lowered, as, when heated to about G00°, nitrate of ammonia explodes with violence. Nitrous oxide may also be made in the same way from crystallized nitrate of ammonia, or by exposing nitric oxide for some days over iron filings, but it requires great care in its preparation.

4062. Test for Pure Laughing Gas

4062.    Test for Pure Laughing Gas. "When pure, it is colorless, has an agreeable odor, and does not affect a solution of nitrate of silver.

4063. Carbonic Acid

4063.      Carbonic Acid. An invisible acidulous gas, formed by the union of 1 equivalent of carbon with 2 of oxygen, having a specific gravity of 1.524, and highly soluble in water. Its general properties and the methods of obtaining it will be found in Nos. 3193, etc.. The application of this gas to the purposes of wine-making, etc., is given in No. 718. The methods for obtaining carbonic acid gas arc given in No. 3914.

4064. Carbonic Oxide

4064.     Carbonic Oxide. A colorless, neutral gas, formed of equal equivalents of carbon and oxygen, and has a specific gravity of .913. It bums with a pale blue flame, and is even more poisonous than carbonic acid.

4065. To Obtain Carbonic Oxide

4065.      To Obtain Carbonic Oxide. Carbonic oxide may be obtained from carbonic acid gas by passing the latter over fragments of charcoal heated to redness in a tube of porcelain or iron.

Also, by treating binoxalate of potassa with 5 or 6 times its weight of oil of vitriol in a glass retort, at a gentle heat.

Equal weights of chalk (or carbonate of soda) and iron filings (or charcoal), strongly heated in an iron retort or gun barrel, will evolve tho gas rapidly.

Whichever way tho gas is evolved, it must be passed first through a caustic alkaline solution or milk of lime, to deprive it of carbonic acid, and next over dried chloride of calcium, to deprive it of moisture. It may be collected either over mercury or water, as the latter absorbs but very little.