JQ^ ON THE METALS OF EARTHS. 



Proportion of We are in possession of no accurate experiments on the 

 metal main- qy^ritity of acids required to dissolve alumine, glucine, and 

 silex; but according to Richter's estirnation of the compo- 

 sition* of phosphate of alumine, aluraine would appear to 

 contain about 56 per cent of metallic matter, 

 and silex. jMr. Berzelius, in a letter which I received from him a 



few months agof, states, that, in making an analysis of 

 cast iron, he found, that it contained the metal of silex ; 

 and that this metal, in being oxidated, took up nearly half 

 its weight of oxigen. 



If the composition of ammonia be calculated upon, ac- 

 cording to the principle above stated, it ought to consist of 

 , 53 of metallic matter, and about 47+ of oxigen, which 



agrees very nearly with the quantity of hidrogen and am- 

 monia produced from the amalgam. 

 Earths former- Though the early chemists considered the earths and the 

 ]y considered metallic oxides as belonging to the same class of bodies, 

 class with ^^^ ^^^ earths as calces which they had not found the means 

 oxides: of combining with phlogiston; and though Lavoisier in- 



lls ^eaiihs and ^''"^^^ upon this analogy with his usual sagacity ; yet still 

 oxides, deem- the alkalis, earths, and oxides, have been generally con- 

 orders'^'^^'^ sidered as separate natural orders. The earths, it has been 

 said, are not precipitated by the triple prussiates, or by the 

 solutions of galls§; and the alkalis and alkaline earths are 

 but apparently both distinguished by their solubility in water: but if such 

 without characters be admitted as grounds of distinct classification, 



the common metals must be arranged under many diiferent 

 divisions; and the more the subject is inquired into, the 

 more distinct will the general relations of all metallic sub- 

 stances appear. The alkalis and alkaline earths combine 



♦ Tbomson's Chemistrj', vol. ii, p. 591. 



\- In the same communication this able chemist informed me, that 

 he had succeeded in decomposing the earths, by igniting them strongly 

 >vith iron and charcoal. 



J I take the proportions of the volumes from the very curious paper 

 of Mr. Gay-Lussac, on the combinations of gaseous bodies, Mem. 

 d'Arcuei!, torn, ii, page 213; and the weights from my own estima- 

 tion, according to which lOO cubic inches of muriatic acid gas weigh 

 J9 grains, at the mean temperature and pressure, which is very nearly 

 the same as the >v€igyit giTen by Messrs. Gay-Lussac, and Thenard, 



^ Klaproth. Annates de Gliimie, torn, x, p. 277. 



with 



reason. 



