Page:Proceedings of the Royal Society of London Vol 1.djvu/298

Rh The inference drawn by Dr. Marcet from the general resemblance is, that the river Jordan might possibly be the source of the saline in- gredients of the Dead Sea, or that the same source of impregnation might be common to both.

In this lecture Mr. Davy, after recalling to our recollection the series of experiments described in his last Bakerian lecture, in which various bodies, consisting of known ingredients, having the highest known affinities for each other, were decomposed by the agency of electricity, reminds us also of a conjecture which he then formed, that a greater intensity of the same power might likewise overcome the aﬂinities of other elements which had not hitherto been separated, and proceeds to inform us that this conjecture is now fully veriﬁed; for that by a laborious experimental application of the powers of electro-chemical analysis, he has been enabled to decompose various bodies which have appeared simple when examined by common chemical means.

Those of his experiments which are in the most mature state, re- late to the decomposition of the ﬁxed alkalies, and to the evolution of new and extraordinary bodies which constitute their bases.

- His ﬁrst attempts to effect the decomposition of these alkalies were defeated by the presence of water, since on that occasion he employed saturated solutions of them in water.

In his second attempt, since solid dry potash is a perfect non-conductor, he kept it in a state of fusion by intense heat, during electrization by a voltaic battery, consisting of 100 6-inch plates, highly charged. Under these circumstances the potash became a conductor; and brilliant light, with an appearance of ﬂame at the negative wire, seemed to prove the development of combustible matter at this point of contact; but on account of the heat employed, no such product could be collected.

The method which he next pursued was more successful, as he found that a very slight addition of moisture renders potash a conductor, and that in this state it readily fuses by the electric power, which at the same time effects its decomposition.

When a piece of potash, weighing as much as forty or ﬁfty grains, was exposed under these circumstances to the action of the battery, consisting of 100 plates of six inches, with 150 of four inches in intense activity, the potash began to fuse at both its points of electrizaﬁon. There was a violent effervescence at the upper, or positive surface (by extrication of oxygen gas, as afterwards appeared), while at the lower, or negative surface, there Was no liberation of elastic