[39] The composition of the acids thus marked, is given from calculations. TABLE II. _Binary Proportions of OXYGENE and NITROGENE in NITRIC and NITROUS ACIDS._[40] +---------------+---+-------+--------+-------------+-------+-------+ | 100 Parts | |Oxygene| Nitro- | | Nitro-|Oxygene| | | | | gene | | gene | | +---------------+---+-------+--------+-------------+-------+-------+ |Nitric Acid | c | 70,50 | 29,50 | | 1 | 2,389 | +---------------+ o +-------+--------+ +-------+-------+ |Bright yellow | n | 70,10 | 29,90 | | 1 | 2,344 | | Nitrous | t | | |Proportions. | | | +---------------+ a +-------+--------+ Nitrogene. +-------+-------+ |Orange coloured| i | 69,63 | 30,37 | Unity. | 1 | 2,292 | +---------------+ n +-------+--------+ +-------+-------+ |Dark Green | | 69,08 | 30,92 | | 1 | 2,230 | +---------------+---+-------+--------+-------------+-------+-------+ [40] Nitrous gas contains 44,05 Nitrogene, and 55,95 Oxygene, as has been said before. XI. I have before mentioned that dilute nitric acids are incapable of dissolving so much nitrous gas in proportion to their quantities of true acid, as concentrated ones. During their absorption of it, they go through similar changes of color; 330 grains of nitric acid, of specific gravity 1,36, after 50 cubic inches of gas had been passed through it, became blue green, and of specific gravity 1,351. It had gained in weight but 3 grains; and when the nitrous gas was driven from it by heat into a water apparatus, but 7 cubic inches were collected.[41] From the diminution of specific gravity of nitric acid by combination with nitrous gas, and from the smaller attraction of nitric acid for nitrous gas, in proportion as it is diluted, it is probable that the nitrated acids, in their combinations with water, do not contract so much as[42] nitric acids of the same specific gravities. The affinities resulting from the small attraction of nitrous gas for water, and its greater attraction for nitric acid, must be such as to lessen the affinity of nitric acid and water for each other. [41] A great portion of it, of course, dissolved in the water with the nitrous acid carried over. [42] Their changes of volume, corresponding to changes of temperature, most probably, are likewise different.