1 96 Electrochemical Researches on 



ner as that I employed for obtaining the metals of the alka- 

 lis. My hopes were, that the potassium and-the metals of 

 the earths might be de-oxygenated at the same time, and 

 enter into combination in alloy. 



In this way of operating, the results were more distinct 

 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 produce 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 minute films, which 

 could not be detached by fusion, and which were instantly 

 destroyed by exposure to air. 



T had found in my researches upon potassium, that when 

 a mixture of potash and the oxides of mercury, tin, or lead, 

 was electrified in the Voltaic circuit, the decomposition was 

 very rapid, and an amalgam, or an alloy of potassium, was 

 obtained ; the attraction between the common metals and 

 the potassium apparently accelerating the separation of the 

 oxygen. 



The idea that a similar kind of action might assist the de- 

 composition of the alkaline earths, induced me to electrify 

 mixtures of these bodies and the oxide of tin, of iron, of 

 lead, of silver, and of mercury ; and these operations were 

 far more satisfactory than any of the others. 



* The power of this combination, though it consisted of one hundred plates 

 of copper and zinc of six inches, and one hundred and fifty of four inches, 

 at this time was not more than equal to that of a newly constructed apparatus 

 of one hundred and fifty of four inches. It had been made for the demon- 

 strations in the Theatre of the Royal Institution in 1803; and since that time 

 had been constantly employed in' the annual course of lectures,' and had 

 served in different parts, for the numerous experiments on the decomposition 

 of bodies by electricity, detailed in the Bakerian Lectures for 1806 and 1807, 

 and a number of the plates were destroyed by corrosion. I mention these 

 circumstances, because many chemists have been deterred from pursuing ex- 

 periments on the decomposition of the alkalis and the earths, under the idea 

 that a very powerful combination was required for the effect. This, how- 

 ever, is far from beiug the case ; all the experiments detailed in the text may 

 be repeated by means of a Voltaic battery, containing from one hundred co 

 vne hundred and fifty plates of four or six inches. 



A mix- 



