Water dissolves but a very small quantity of this gas : according to Dr. Henry, 100 cubic inches take up only 1.I7 cubic inches of the gas ; Dr. Dalton states it to be 2.5, and Saussure cubic inches. It is fatal to animals when respired by itself, as implied by the term azote ; it extinguishes flame immediately ; no degree of cold and pressure to which this gas has been subjected has condensed it to a fluid form.
Nitrogen resembles all other elementary bodies in being destitute of acid or alkaline powers ; its affinity for substances, both elementary and compound, appears to be extremely weak, there being very few with which it combines by mere mixture, or by the action of heat under common circumstances. By electricity, however, or by the intense heat which the electric discharge excites, it may be made to combine with oxygen, and the result is nitric acid. The experiment was first made by Dr. Priestley ; but the true nature of the action, and the result of lt, were ascertained by Mr. Cavendish. [Name Am.] Although the propertied of nitrogen are rather of a negative than a description, and although its affinities are weak, yet it enters into the composition of a great number of important compounds.
With hydrogen it constitutes the alkali Ammons., already described; with chlorine and iodine it gives rise to detonating compounds; with carbon it forms Craxoeitte; and with phosphorus a phosphide : it also combines with some of the metals forming nitride,, but they are all very unstable. It enters into the composition of most animal matters except fat ; is seldom a constituent of the vegetable acids, but invariably forms a part of the vegetable Although nitrogen itself is fatal to animals, yet it is a most im portant constituent of the air,serving to moderate the action of oxygen during combustion, and the too great excitement which that gas respired unmixed would produce on the animal system. It appears also from the experiments of 3lajendie that animals cannot live on food that contains no nitrogen.
The equivalent of nitrogen is 14; combining volume, 2.
Oxides of nitrogen.—The compounds of nitrogen with oxygen are five ; their names and formula) are :— 1. Protoxide of nitrogen . . . . . NO 2. Itinoxida of nitrogen NO, S. Nitrous acid NO, 4. Peroxide of nitrogen NO, S. Nitric acid NO, • 1. Protoxide of nitrogen, nitrous o.ride, or laughing gat. (NO.) This compound was first obtained by Dr. Priestley, who called it dephlogis ticated nitrous air : ho procured it by exposing binoxido of nitrogen to the action of iron, which deprived it of a portion of its oxygen, and reduced it to the state of protoxide of nitrogen. The properties of this gas were minutely examined by Davy. Tho best method of procuring it is to subject nitrate of ammonia to moderate heat is a retort; both the nitric acid and ammonia are decomposed, and their elementary oxygen, hydrogen, and nitrogen recombine in such propor tions as to form water and nitrous oxide gas, thus :— o 4110 + 2N0 Nitrate of Water. Protoxide of
111111.7013111. nitrogen.
One ounce of the nitrate furnishes about one hundred cubic inches of gas.
Protoxide of nitrogen is colourless and transparent, its smell is peculiar but rather agreeable, and its taste Ls sweet : 100 cubic inches weigh about 47 grains, and its specific gravity is P527. Water absorbs about an equal bulk of this gas, but on being heated, gives it back unchanged. It has no action upon uncombined oxygen, in which it differs remarkably from the binoxide. It is composed of one volume of oxygen and two volumes of nitrogen condensed by combination into two volumes.
Protoxide of nitrogen supports combustion, and a taper, ignited phosphorus, sulphur, and charcoal burn vividly in it ; at a red heat it is resolved into its constituent gases in the proportions stated. When a mixture of one volutno of this gas and one of hydrogen is fired by the electric spark, water is produced, and one volume of nitrogen remains : this shows that it must contain half a volume of oxygen, that amount being required to form water with the one volume of hydrogen.
This gas was auppoaed to be irrespirable, until Davy, in his 'Researches on Nitrous Oxide. showed that it might be breathed for a short time with impunity. When required for inhalation it should be prepared from pure nitrate of ammonia, should be collected over water, and allowed to stand in contact with that liquid for a few hours. It is most conveniently taken into the lungs from an india-rubber bag, furnished with an ivory mouth piece, the passage into the bag being freo and of considerable size. The effects it produces vary considerably with different individuals. After a few inspirations the body of the person usually commences to describe a kind of rolling movement, similar to that which frequently occurs under the influence of intoxication, the bag is clutched more earnestly, and inspirations taken more zealously, until in from one to three minutes the subject either suddenly rushes among the bystanders in a state of enthusiastic pugilahn, or shrieks and is convulsed with laughter, or, in a condition of unstable equilibrium, stands blinking at nothing, with a grinning, semi-Idiotic gaze. Protoxide of nitrogen has well earned for itself the name of laughing gas, not so much perhaps from the effects it produces on the patient, as from the roars of laughter elicited from thoao who witness Its inhalation.