Supposing that a similar kind of action might assist the decomposition of the alkaline earths, he proceeded to institute a series of experiments upon that principle; and the results were more satisfactory than those obtained by the preceding methods of experimenting--a compound was obtained which acted upon water with the evolution of hydrogen, producing a solution of the earth, and leaving free the tin, or lead, with which its base may be supposed to have been alloyed;--but in all such experiments the quantity of the metallic basis produced must have been very minute, and its character very questionable. In this stage of the enquiry, Davy received the letter from Professor Berzelius of Stockholm, the contents of which he embodied in his memoir, accompanied with such observations as his own information suggested. "A globule of mercury, electrified by the power of a battery consisting of five hundred pairs of double plates of six inches square, weakly charged, was made to act upon a surface of slightly moistened barytes, fixed upon a plate of platina. The mercury gradually became less fluid, and after a few minutes was found covered with a white film of barytes; and when the amalgam was thrown into water, hydrogen was disengaged, the mercury remained free, and a solution of barytes was formed. "The result with lime, as these gentlemen had stated, was precisely analogous. "That the same happy methods must succeed with strontites and magnesia, it was not easy to doubt, and I quickly tried the experiment. From strontites I obtained a very rapid result; but from magnesia, in the first trials, no amalgam could be procured. By continuing the process, however, for a longer time, and keeping the earth continually moist, at last a combination of the bases with mercury was obtained, which slowly produced magnesia, by absorption of oxygen from air, or by the action of water. "All these amalgams I found might be preserved for a considerable period under naphtha. In a length of time, however, they became covered with a white crust under this fluid. When exposed to air, a very few minutes only were required for the oxygenation of the bases of the earths. In the water the amalgam of barytes was most rapidly decomposed; that of strontites, and that of lime next in order: but the amalgam from magnesia, as might have been expected from the weak affinity of the earth for water, very slowly changed: when, however, a little sulphuric acid was added to the water, the evolution of hydrogen, and the production and solution of magnesia, were exceedingly rapid, and the mercury soon remained free."