2. When agitated in boiled water, it was rapidly absorbed, leaving a residuum of rather more than one twelfth. 3. The taper burnt in it with increased brilliancy, the flame being long, and deep red at the edges. 4. Iron introduced into it ignited, burnt with a dull red light. 5. Green vegetables exposed to it were instantly rendered white. 6. It underwent no diminution, mingled with atmospheric air. 7. When mingled with nitrous gas, it gave dense red vapor, and rapid diminution. [148] This deep color depended, in some measure, upon the nitro-muriatic vapor suspended in it. I have since observed that it is more intense in proportion as the heat employed for the production of the gas has been stronger. The natural color of the peculiar gas is deep yellow. _c._ From the exhibition of these properties, it was evident that the gas produced during the solution of platina in aqua regia, chiefly consisted of oxygenated muriatic acid, or of a gas highly analogous to it. It was, however, difficult to conceive how a body, by combining with a portion of the oxygene of nitro-muriatic acid, could produce from it oxygenated muriatic acid, apparently mingled with very small portions of any other gas. _d._ To ascertain whether any permanent gas was produced during the ebullition of aqua regia, of the same composition as that used for the solution of the platina; I kept a large quantity of it boiling for some time, in communication with the water apparatus; the gas generated appeared to be wholly nitro-muriatic, and was absorbed as fast as produced, by the water. _e._ To determine whether any nitrous oxide was mingled with the peculiar gas, as well as the nature and quantity of the unabsorbable gas, nitrous gas was gradually added to 21 cubic inches of the gas produced from a new solution, till the diminution was complete: the gas remaining equalled 2,3 cubic inches; it was unabsorbable by water, and extinguished flame. In another experiment, when the last portions of gas from a solution were carefully received in water previously boiled, 12 cubic inches agitated in water left a residuum of 1.3; whilst the same quantity decomposed by nitrous gas, containing,02 nitrogene, left about 1.5. Hence it appeared that the aëriform products of the solution consisted of the peculiar gas analogous to oxygenated muriatic acid, and of a small quantity of nitrogene. _f._ Consequently a portion of the nitric acid of the aqua regia had been decomposed; but if it had given oxygene both to the platina and muriatic acid, the quantity of nitrogene evolved ought to have been much more considerable. _g._ To ascertain if any water had been decomposed, and the nitrogene condensed in the solution by its hydrogene, to form ammoniac, I saturated a solution with lime, and heated it, but no ammoniacal smell was perceived.