Concentrated solution of potash absorbed a fourth of its bulk of nitrous oxide. When the impregnated solution was heated, globules of gas were given out from it rapidly; but the quantity collected was too small to examine. Soda, whether solid or in solution, exhibited exactly the same phænomena with nitrous oxide. The solution of soda absorbed near a quarter of its bulk of gas. _c._ 11 measures of ammoniacal gas were mingled with 8 measures of nitrous oxide over dry mercury, both of the gases being saturated with water. No change of appearance was produced by the mixture, and they filled, after two minutes, a space equal to 19. On the introduction of a little water, the ammoniac was absorbed, and the nitrous oxide remained unaltered, for it was dissolved by water as rapidly as if it had never been mingled with ammoniac.[155] [155] The Dutch chemists have asserted, that mixture with ammoniac prevents the absorption of nitrous oxide by water, either wholly or partially. Journal de Physique, t. xliii. part ii. pag. 327. It is difficult to account for their mistake. 7 measures of nitrous oxide, exposed to 6 measures of solution of ammoniac in water, was in an hour diminished to 4½ nearly. When the solution was heated over mercury, permanent gas was produced, which was unabsorbable by a minute quantity of water, and soluble in a large quantity; consequently it was nitrous oxide. _d._ Nitrous oxide was exposed to dry caustic strontian; it underwent a diminution of nearly one fortieth, which most likely was owing to the combination of the strontian with its water. 11 measures of nitrous oxide were agitated in contact with 8 of strontian lime water: nearly 4 measures were absorbed. The impregnated solution exposed to heat, rapidly gave out its gas; 3 measures were soon collected, which mingled with a small quantity of hydrogene, and inflamed by the taper, gave a smart detonation. _e._ Nitrous oxide exposed to lime and argil, both wet and dry, was not in the slightest degree acted upon. From these experiments it is evident that nitrous oxide in the aëriform state cannot be combined either with the alkalies, or the alkaline earths. That a combination may be effected between nitrous oxide and these substances, it must be presented to them, in the _nascent state_. The salts composed of the alkalies and nitrous oxide, are not analogous to any other compound substances, being possessed of very singular properties. Before these properties are detailed, it may not be amiss to give an account of the accidental way in which I discovered the mode of combination.