ON tHE DECOMPOSITION Of tHE EARTH5. 369 



%!ned with the iron, so as to form alloys deconiposible by 

 the oxigen of air or water; but the indistinctness of the ef-= 

 feet, and the coinplicatcd circumstances required for it, 

 were such as to compel me to form other plans of operation. 



The strong attraction of potassium for oxigen induced Potassium tried 

 me to try whether this body might not detach the oxigen oxi^mrfrUl** 

 from the earths, in the same manner as charcoal de com- the earths. 

 poses the common metallic oxides. 



I heated potassium in contact with dry pure lime, barytes. Ineffectual. 

 Strontites, and magnesia, in tubes of plate glass ; but as I 

 was obliged to use very small quantities, and as I could not 

 raise the heat to ignition without fusing the glass, I ob- 

 tained in this way no good results. The potassium ap- 

 peared to act upon the earths and on the glass, and dark 

 brown substances were obtained, which evolved gas from 

 water; but no distinct metallic globules could be procured: 

 from these circnmstances, and other like circumstances, it 

 seemed probable, that though potassium may partially de- 

 oxigenate the earths, yet its affinity for oxigen, at least at 

 the temperature which I employed, is not sufficient to etfect 

 their decomposition. 



I'-made mixtures of dry potash in excess and dry barytes, Potash and the 

 lime, strontites, aud magnesia, brought them into fusion, r^'^l'^Vn ^n^** 

 and acted upon them in the voltaic circuit in the same man- 

 ner as that I employed for obtaining the metals of the 

 alkalis. My hopes were, that the potassium and the 

 ttietals of the earths might be deoxigenated at the same 

 time, and enter into combination in alloy. 



In this way of operating, the results were more distinct The results 

 than in the last: metallic substances appeared, less fusible ',^'^.^'"'"°'^* 

 than potassium, which burnt the instant after they had 

 formed, and which by burning produced a mixture of 

 potash and the earth employed ; I endeavoured to form 

 them under naphtha, but without much success. To pro- 

 duce the result at all required a charge by the action of 

 nitric acid, which the state of the batteries did not permit 

 me often to employ*; and the metal was generated only in 



very 



* The power of this combination, thougli it consisted of one The Voltaic 

 hundred plates of copper and zinc of six inches, and one hundred ^*^*^'y^^^''^'^^'^" 



Vol. XXI. — Supplement. 2B and 



