on various Objects. 89 



Jvf . Berzelius *, in a letter which 1 received from him a 

 few months ago, states, that in making an analysis of cast 

 iron, he found that it contained the metal of silex, and m&£ 

 this metal in being oxidated took up nearly halt* its weight 

 of oxygen. 



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 t of oxygen, whic*. 

 agrees verv nearly with the quantity off hydrogen and 

 ammonia produced from the amalgam. 



Though the early chemists considered the earths and the 

 metallic oxides as belonging to the same class of bodies, 

 and the earths as calces which they had not found the 

 means of combining with phlogiston, and though Lavoisier 

 insisted upon this analogy with his usual sagacity, yet still 

 the alkalies, earths, and oxides have been generally con- 

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

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

 solutions of galls t ; and the alkalies and alkaline earths 

 are both distinguished by their solubility in water; but if 

 such characters be admitted as grounds of distinct classi- 

 fication, the common metals must be arranged under many 

 different divisions ; and the more the subject is inquired 

 into, the more distinct will the general relations of all me- 

 tallic substances appear. The alkalies and alkaline earths 

 combine with prussic acid, and form compounds of dif- 

 ferent degrees of solubility ; and solutions of barytes (as 

 has been shown bv Dr. Henry and M. Guvton) precipitate 

 the triple prussiate of potash; the power of combination is 

 general, but the compounds formed are soluble in different 

 degrees in water. The case is analogous with solutions off 

 galls ; these, as I have mentioned in a paper published in 

 the Philosophical Transactions for 180.5, are precipitated by 

 almost all ncuirosaline solutions; and they form com- 

 pounds more or less soluble in water, more or less coloured* 

 and differently coloured with all salifiable bases. It is 

 needless to dwell upon the combinations of the alkalies and 



* In the same communication this able chemist Informed me, that lie had 

 .succeeded in decomposing the earths, by igniting them strongly with iron 

 and charcoal. 



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

 jMT. Gay Lussac, on the combinations of gaseous bodies, Mnu. d\hiutil> 

 fom. ii. page '-'13, and the weights from mv own estimation, according to 

 which 100 cubic inches of muriatic acid gas weigh 39 grains, at the mean 

 temperature and pressure, which is very nearly the same as the weight 

 given by MM. Gay Lussac and Thenard. 



£ Ktaproth, Annates de Ckuuir, tome s, ;•:. *77. 



earths, 



