ON THE METALS OF EARTHS. |QJ 



with prussic acid, and form compounds of different degrees 

 of solubility ; and solutions of barytas (as has been shown by 

 Dr. Henry and Mr. Guyton,) precipitate the triple prus- 

 siate 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 of galls ; these, 

 as I have mentioned in a paper published in the Philosophi- 

 cal Transactions for 1805, are precipitated by almost all 

 neutrosaline solutions; and they form compounds more or 

 less soluble in water, more or less coloured, and differently 

 coloured with all salifiable bases. Tt is needless to dwell 

 upon the combinations of the alkalis and earths with oils, to 

 form soaps; and of the earthy soaps some are equally in- 

 soluble with the metallic soaps. The oxide of tin, and 

 other oxides abounding in oxigen, approach very near ia 

 their general characters to zircon, silex, and alumine; and 

 in habits of amalgamation, and of alloy, how near do^ the 

 metals of the alkalis approach to the lightest class of 

 oxidable metals? 



It will be unnecessary, I trust, to pursue these analogies 

 any farther; and I shall conclude this section by a few re- 

 marks on the alloys of the metals of the common earths. - 



It is probable, that these alloys may be formed in many Alloys formed 

 metallurgical operations ; and that small quantities of them c^Upetations 

 may influence materially the properties of the compound, v/hich affect 

 in which .hey exisN '^:^. 



In the conversion of cast into malleable iron, by the pro- as iron, 

 cess of blooming, a considerable quantity of glass separates, 

 which, as far as I have been able to determine, from a 

 coarse examination, is principally silex, alumine, and lime, 

 vitrified with oxide of iron. 



Cast iron from a particular spot will make only cold short 

 iron; while, from another spot, it will make hot short: but 

 by a combination of the two in due proportions, good iron is 

 produced. May not this be owing to the circumstance of 

 their containing different metals of the earths, which in 

 compound alloys may be more oxidable than in simple 

 alloys, and may be more easily separated by combustion ? 



Copper, Mr. Berzelius informs me, is hardened by 

 silicium. In some experiments that I made on the action a"^ copper. 



of 



