IBIe InfelU^ence and Miscellaneous Artides. 



that work, rendered necessary by new ol>servations and by tlie vast 

 accession of new genera and orders, brouglit from the tropics. 

 South America, Australia, and elsewhere, he devoted the remainder 

 of his life. His later memoirs, many of which are of great value, ane 

 chiefly contained in the Amiales, and sul>sequently in the Memoires 

 du Musetmi d Histoire Naturelle. M. de Jussieu was a man of very 

 simple manners and amiable character, of a social and aflectioiiate tem- 

 per, and a perfect stranger to scientific jealousies and intrigues. He 

 attained to an extreme old ago, and had the happiness of witnessing 

 the almost universal adoption of that system of botanical arrange- 

 lUfcnt, tlie estaWishment of which had formed the great object of the 

 laboui-s of his life. 



M, 



XXXI. Intelligence and Miscellaneous Articles, 



€>N THE REDUCTION OF METALS BY ELECTRICITY. 



BECQUEREL, on presenting some electro-chemical appa- 

 • ratus to the Academic Royale des Sciences of Paris, by the 

 aid of which he bad been able to effect the immediate reduction of sil- 

 ver, lead and copper,stated that, without the intervention of mercury, 

 by constructing an electro-chemical apparatus with iron, a saturated 

 solution of common salt, and an ore of silver, properly prepared, he 

 had extracted from the latter the silver which it contained, under the 

 form of crystals. The minerals on which the experiments were 

 made were the ores raised in Columbia and the ore of Allemont. 

 The same method has also been successfully employed to extract 

 from the copper pyrites of Chessy, near Lyons, the silver which 

 it contains, without affecting the copper. It is only from the ar- 

 gentiferous galenas that it is difficult to extract the silver. When 

 a mineral like that of Aliemont contains many metals, as lead, 

 copper, &c., each of these metals is separately reduced and at dif- 

 ferent times, so that the separation is easily effected. From this it 

 results that the ores of lead and copper may be treated in the same 

 manner as those of silver, but with much less facility, because of the 

 different degrees of oxidation which they acquire, and the com- 

 pounds which they form during roasting. M. Becquerel is at pre- 

 sent occupied with further researches on the extraction of metals, 

 but deeme.l it proper, for the interests of science, to make known 

 to the Academy the principle by means of which he had been able 

 to extract some metals, particularly silver, from their respective 

 ores.-^Vlustitiity Mars 2, 1836. 



ON A SIMPLE METHOD OF OBTAINING SPONGY PLATINA. 



To obtain spongy platina, M. Dobereiner fuses crude platina with 

 twice its weight of zinc, and treats the alloys, when powdered, first 

 with dilute sulphuric acid, and then with nitric acid also diluted, to 

 oxidize and dissolve all the zinc, which, contrary to theory, takes 

 place but slowly, even with heat : there is thus obtained an insolu- 

 ble greyish black residue of finely divided but impure platina, which, 



