296 Extrication of the Alkalifiable Metals, 



had the color of silver, took fire and burnt, with an intense white 

 hght, into quickhme."* 



Had the failure of Sir Humphrey, in his efforts to isolate cal- 

 cium, been due only to the accidental fracture of a glass tube, 

 it would be inexplicable that a chemist so indefatigable should 

 not have successfully reiterated the experiment ; 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 apparatus, no chemist could succeed in the 

 isolation of calcium, nor in the complete distillation of the mer- 

 cury from the amalgams of the other metals, so as to obtain avail- 

 able quantities for examination. 



In a subsequent communication to the Royal Society, Davy 

 mentions, that '' by passing potassium through lime and magne- 

 sia, and then introducing mercury, I obtained solid amalgams, 

 consisting of potassium, the metal of the earth employed, and 

 mercury." 



" The amalgam from magnesia was easily deprived of its potas- 

 sium by water." Of the amalgam containing calcium he makes 

 no farther mention, but suggests the possibility of obtaining, by 

 operations performed in this manner, quantities of the metals of 

 the earths sufficient for determining their nature and agencies.f 



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 obtaining amal- 

 gams of Calcium, Barium, and Strontium from saturated so- 

 lutions of their Chlorides, hy exposure to the Voltaic circuit in 

 contact with msrcury. 



A and B, two bell glasses, with perforated necks, were invert- 

 ed and placed one within the other, so that, between them, there 

 was an interstice of half an inch, which was filled with a freez- 

 ing mixture. Concentrically within B a third similar bell F, 



* See Transactions of the Royal Society, Part 11. Nich'olson's Journal, Vol. 

 xxi, for 1808 ; or, Tilloch's Philosophical Magazine, Vol. xxxiii. 



t Transactions Royal Society for 1810, part I, p. 62. Tilloch's Magazine, vol. 

 xxxvi, p. 87. 



