34 ON THE EXTRICATION OF THE ALKALTFIABLE METALS 



ment; or that no other chemist, during thirty intervening years, should have 

 succeeded by resorting to the same means. No doubt exists in my mind that, 

 without using a larger quantity of mercury than the sixty grains which he 

 employed, and resorting to other materials than glass for a distillatory appa- 

 ratus, no chemist could succeed in the isolation of calcium, nor in the complete 

 distillation of the mercury from the amalgams of the other metals, so as to 

 obtain available quantities for examination. 



In a subsequent communication to the Royal Society, Davy mentions that, 

 " by passing potassium through lime and magnesia, and then introducing mer- 

 cury, I obtained solid amalgams, consisting of potassium, the metal of the earth 

 employed, and mercury." 



" The amalgam from magnesia was easily deprived of its potassium by 

 water." Of the amalgam containing calcium he makes no farther mention, 

 but suggests the possibility of obtaining, by operations performed in this man- 

 ner, quantities of the metals of the earths sufficient for determining their nature 

 and agencies.* 



But I will proceed to explain and describe the apparatus and process to 

 which I have resorted, and to communicate the results which I have obtained. 



A Description of the Apparatus and Process for oUaining Amalgams of Cal- 

 cium. Barium, and Strontium from saturated solutions of their Chlorides, by 

 exposure to the Voltaic Circuit in contact ?vith Mercury. 



A and B, two bell glasses, with perforated necks, were inverted and placed 

 one within the other, so that, between them, there was an interstice of half an 

 inch, which was filled with a freezing mixture. Concentrically within B a 

 third similar bell, F, was placed, including a glass flask, of which the stem 

 extended vertically through the neck of F. From a vessel, V, with a cock 

 intervening, a tube luted to the orifice of the flask extended to the bottom of it, 

 so as to convey thither from V a current of ice-water, which, after refrigerating 

 the bulk of the flask, could escape through the nozzle projecting, horizontally, 

 from the neck, T. The mercury in the capsule D communicates through the 

 rod with the negative poles of one or more deflagrators. The capsule L in 

 like manner with the corresponding positive poles. 



* Transactions Royal Society for 1810, part L, p. 63. Tilloch's Magazine, vol. xxxvi. p. 87. 



