ON THE BECOMPOSITION OS' THE EARTHS. 367 



eafUest periods of chemistry, of their being metallic ia their 

 nature*. ^ 



Many difficulties however occurred in the way of obtain- Many difficul- 

 ing complete evidence on this subject: and the pursuit of ties occuned- 

 the inquiry has required much labour, and a considerable 

 derotion of time, and has demanded more refined^and com- 

 plicated processes, than those which had succeeded with the 

 fixed alkalis. 



* Beccher is the first chemist, as far as my reading informs me, Early notions 

 who distinctly pointed out the relations of metals to earthy sub- ^^ ^he metallic 

 stances, see Phys. subt. Lipsiee, 4tOj p. 61. He was followed by g^j.j}j 

 Stahl, who has given the doctrine a more perfect form. Beccher's 

 idea was that of a universal elementary earth, which, by uniting 

 to an inflammable 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 

 phlogiston ; see Slahl Fundament. Chym. p. 9, 4to, and Conspect. 

 Chem. 1, 77, 4to. — Neuman gives an account of an elaborate 

 series of unsuccessful experiments which he made to obtain a metal 

 from quicklime. Lewis's Neuman's Chem. Works, 2d. edit, 

 vol. i, p. 15. The earlier English chemical philosophers seem to 

 have adopted the opinion of the possibility of the production of 

 metals from common earthy substances; see Boyle, vol. i, 4to, p. 

 564, and Grew, Anatomy of Plants, lee. ii, p. 242. But these 

 notions were founded upon a kind of alchemical hypothesis of a, 

 general power in nature of transmuting one species of matter 

 into another. Towards the end of the last century the doc- 

 trine was advanced in a more philosophical form ; Bergman sus- 

 pected barytes to be a m.etallic calx, Pra'f. Sciagrap. Reg. Min. 

 and Opusc. iv, 212. Baron supported the idea of the probability of 

 alumine being a metallic substance, see Annalesde Chemie, 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 t!ie assertion of Tondi 

 and Ruprecht, that the earths might be reduced by charcoal ; and 

 the accurate researches of Klaproth and Savaresi, who proved by 

 the most decisive experiments, that the metals taken for the bases 

 of the earths were pnosphurets of iron, obtained from the bone 

 ashes and other materials employed in the experiment, Annalc>« dc 

 Chemie, vol. viii, p. 18, and vol. x, p. 257, 275. Amidst all 

 these hypotheses, potash and soda were never considered as metallic 

 in their nat'ue ; Lavoisier supposed ihera to contain azote ; nor at 

 that time were there any analogies, to lead thai, acute philosophci 

 to a happier conjecture. 



5 The 



