The whole solution evaporated, gave 18 grains of compact nitrate of ammoniac. But reasoning from the quantity of carbonate of ammoniac employed, the free nitric acid was equal to 2,75 grains, and this must have formed 3,56 grains of salt. Consequently the salt pre-existing in the solution was about 14,44 grains. But besides the fluid taken out of the recipient, 2 grains remained in it: let us suppose this, and the 4 grains lost, to contain 2 of salt, and,6 of free acid. Then the undecompounded salt is 5,5 + 14,4 + 2 = 21,9 The free acid 2,75 + ,6 = 3,35 Gas 42,5 Water 32,25 —————— 100 Now about 78,1 grains of salt were decompounded, and formed into 42,5 grains of gas, 3,35 grains acid, and 32,25 grains water. But there is every reason to suppose, that in this process, when the hydrogene of the ammoniac combines with a portion of the oxygene of the nitric acid to form water, and the nitrogene enters into union with the nitrogene and remaining oxygene of the nitric acid, to form nitrous oxide; that water pre-existing in nitric acid and ammoniac, such as they existed in the aëriform state, is deposited with the water produced by the new arrangement, and not wholly combined with the nitrous oxide formed. Hence it is impossible to determine with great exactness, the quantity of water which was absolutely formed in this experiment. 78,1 grains of salt are composed of 15,4 alkali, 58 acid, and 4,7 water. And reasoning from the different affinities of water for nitric acid, ammoniac, and nitrous oxide, it is probable that ammoniac, in its decomposition, divides its water in such a ratio, between the nitrogene furnished to the nitrous oxide, and the hydrogene entering into union with the oxygene of the nitric acid, as to enable us to assume, that the hydrogene requires for its saturation nearly the same quantity of oxygene as when in the aëriform state; or that it certainly cannot require less. But 15,4 alkali contain 3,08 hydrogene, and 12,32 nitrogene;[87] and 3,08 hydrogene require 17,4 of oxygene to form 20,48 of water. [87] Owing part of their weight to an unknown quantity of water. Now 32,5 grains of water existed before the experiment; 4,7 grains of water were contained by the salt decomposed, and 32,5-4,7 = 27,8: and 27,8-20,48, the quantity generated, = 7,52, the quantity existing in the nitric acid.