[75] When nitrous gas exists in neutro-saline solutions, they are always colored more or less intensely, from yellow to olive, in proportion to the quantity combined with them.
[76] Hence a nitrate of ammoniac with excess of acid, when exposed to heat, first becomes yellow, and then white.
[77] The accounts given by different chemists of the composition of nitrate of ammoniac, are extremely discordant; they have been chiefly deduced from decompositions of carbonate of ammoniac (the varieties of which have been heretofore unknown) by nitrous acids of unknown degrees of nitration. Hence they are particularly erroneous with regard to the alkaline part. Wenzel supposes it to be 32 per cent, and Kirwan 24. Addit. Observ. pag. 120.
[78] Mem. Par. 1783. See Irish Trans. vol. 4.
[79] Addit. Obs. pag. 120.
[80] Two measures of air dispelled from this water by boiling, mingled with 2 of nitrous gas, diminished to 2,4 nearly.
[81] Experiments and Observations, vol. 2, pag. 89. Last Edition.
[82] A minute quantity, however, must have been absorbed, and given out again when the charcoal was heated.
[83] Strong solution of ammoniac has no attraction for nitrous oxide.
[84] The gas was examined by those tests in order to prove that no water had been decomposed.