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XXXIV. Electrochemical Researches on (he Decomposition 



of the Earths ; with Observations on the Metals obtained 



from the alkaline Earths, and on the Amalgam procured 



from Ammonia. By Humphry Davy, Esq., Sec. R.S, 



M.R.I. A. Prof. Chem. R.I.* 



I. Introduction. 



In the Philosophical Transactions for 1S07, Part I. f and 

 1&03, Part I. J, I have detailed the general methods of de- 

 composition hy electricity, and stated various new facts ob- 

 tained in consequence of the application of them. 



The results of the experiments on potash and soda, as I 

 stated in. my last communication to the Society, afforded 

 me the strongest hopes of being able to effect the decom- 

 position both of the alkaline and common earths; and the 

 pbcenomena obtained in the first imperfect trials made upon 

 those bodies, countenanced the ideas that had obtained from 

 the earliest periods of chemistry, of their being metallic in 

 their nature §. 



Many 



* From Philosophical Transactions for 1808. Part II. 



+~5eePhil. Mag. vol.xxviii. p. 1, 104, 220. i Ibid. vol. xxxii. p. I, 9J, 146.- 



§ Becchcr is the first chemist, as far as my reading informs me, who di- 

 stinctly pointed out the relations of metals to earthy substances j See Phys. 

 snbt. Lip-.ix, 4to, p. 61. He was followed by Stahl, who has given the doc- 

 trine a more perfect form. Beccher's idea wa» that of an universal elementary 

 earth, which, by uniting to an inilammable earth, produced all the metals, 

 and under other modifications formed stones. Stahl admitted distinct earths 

 which he supposed might be converted into metals by combining with phlo- 

 giston; see Stahl Fundament. Chym. p. 9, 4to, and Conspect. Chem. 1,77, 

 4to. — Neuman gives an account of an elaborate series of unsuccessful experi- 

 ments which he made to obtain a metal from quicklime. Lewi's Neuman's 

 Chem. Works, 2d. edit. vol. i. p. 15. The earlier English chemical philoso- 

 phers seem to have adopted the opinion of the possibility of the preduction of 

 metals from common earthy substances ; See Boyle, vol. i. 4to, p. 564, and 

 Grew, Anatomy of Plans, let. ii. p. 24:2. But these notions were founded 

 upon a kind of alchemical hypothesis of a general power in nature of trans- 

 muting one species of matter into another. Towards the end of the last cen- 

 tury the doctrine was advanced in a more philosophical form ; Bergman sus- 

 pected barytes to be a metallic calx, Praf. Sciagrap. Reg. Min. and Opusc. 

 jv. p. 212. Baron supported the idea of the probability of alumine being a 

 metallic substance, See Annates de Chime, vol. x. p. 257. — Lavoisier extended 

 these notions, by supposing the other earths metallic oxides. Elements, 2d 

 edit. Kerr's translation, p. 217. The general inquiry was closed by the as- 



Vol. 32. No. 127, Dec. 180S, N sertion 



