_Chloride Magnesium._--When solid and wire fuzed in non-conductor--When fuzed conducted very well and was decomposed A and P Pole much action and gas--chlorine? At N Pole Magnesium separated and no gas. Sometimes Magnesium burnt flying off in globules burning brilliantly. When wire at that pole put in water or white M A [muriatic acid] matter round it acted powerfully evolving hydrogen and forming Magnesia; and when wire and surrounding matter heated in spirit lamp _Magnesium_ burnt with intense light into _Magnesia_. VERY GOOD EXPT. This recalls the “capital experiment” entry which Sir Humphry Davy wrote after the account of his decomposition of caustic potash. On the 7th of April we come to a marvellous page of speculations. He has seen that liquids, both solutions and fused salts, can be decomposed by the current, and that at least one solid is capable of electrolysis. But he finds that alloys and metals are not decomposed. He finds that electrolysis is easiest for those compounds that consist of the most diverse elements, and is led on to speculate as to the possible constitution of those conductors that the current does not decompose. This may involve a recasting of accepted ideas; but from such a step he does not shrink, as the following extracts show:-- Metals _may_ not be compounds of elements most frequently combined, but rather of such as are so similar to each other as to pass out of the limit of voltaic decomposition. 13th April (same page). If voltaic decomposition of the kind I believe then review all substances upon the new view to see if they may not be decomposable, &c. &c. &c. [Sidenote: ATTRACTION BY POLES DOUBTED.] He has now found that the facts observed do not admit of being explained on the supposition that the motion of the ions is due to the attraction of the poles, and accordingly there follows the entry:-- (Ap. 13, 1833.) A single element is never attracted by a pole, _i.e._ without attraction of other element at other pole. Hence doubt Mr. Brande’s Expts on attraction of gases and vapours. Doubt attraction by poles altogether.