Page:Proceedings of the Royal Society of London Vol 1.djvu/505

Rh iode with hydrogen; whilst the oxidated base remains in solution in the state of sulphate of potash.

When the same compound is acted upon by nitric acid, nitrous gas and the purple vapour are extricated.

When this compound is acted upon by liquid muriatic acid, it is completely dissolved. The excess of muriatic acid may be driven off by heat, and the acid formed by iode and hydrogen found in the liquor.

When oxy-iodate of potash is dissolved in muriatic acid, muriate of potash crystallizes, and the yellow compound of oxymuriatic gas and iode remains in solution.

When liquid ammonia is poured upon iode, the black fulminating powder observed by lWM. Desormes and Clement is produced; and the salt remaining in solution is found by Sir Humphry Davy to con- sist of ammonia combined with iodic acid, such as was before formed by the union of iode and hydrogen; and he hence infers that the ful- minating compound consists of iode and azote, since no azote escapes during its formation.

From several experiments made upon the proportion in which this body unites with potassium, or with potash and with sodium, the author infers that the number representing it will be about 165, that for potassium being 75; and consequently that the acid gas formed by its union with hydrogen must be by far the heaviest known gas.

With respect to the electro-chemical properties of iode, the author observes that it is not decomposed by voltaic electricity from points of charcoal exposed to it in the state of purple vapour; that it is a non-conductor of electricity; that it appears at the positive pole when salts containing it are decomposed in the voltaic circuit, with the exception of its combination with chlorine, from which it is, on the contrary, found to pass to the negative surface.

From all these facts, the author infers that iode is an undecom- pounded body, resembling metals in speciﬁc gravity, lustre, colour, and high elementary weight; in chemical agency and electro-cbe- mical habitudes resembling chlorine, ﬂuorine, and oxygen, having a stronger aﬂinity than oxygen for most metals, but extricated from most of them by chlorine; agreeing With chlorine and ﬂuorine in forming a strong acid with hydrogen; and with oxygen in forming an acid with tin, and substances apparently alkaline, with potassium or sodium, which neutralize dry boracic acid, and form with it a purple glass, from which iode may be separated by sulphuric acid.

In conclusion the author observes, that the acid formed by this body with hydrogen and with tin may be termed hydriodic and stanniodic acids. But for the salts which it forms with various bases, he proposes some termination which shall be merely arbitrary, as Argentama, for the compound it forms with silver; Calcama, for its compound with lime, 8w. ; so that the ﬂuate, iodate, and muriate of lime are to be distinguished by the appellations of calcala, calcarna, calcana.