32 ON THE EXTRICATION OF THE ALKALIFIABLE METALS, 



was in search, and stated many facts and arguments tending to prove that it 

 was the most perfect form of the apparatus at that time known. More than 

 twelve years ago, while I was operating with a deflagrator of three hundred 

 pairs, each seven inches by three, I observed that, in a circuit made through 

 a saturated solution of chloride of calcium, by means of a coarse platina wire 

 (No. 14) and a fine wire, (No. 26,) that when the latter was made the cathode 

 and the former the anode, a most intense ignition resulted, causing the rapid 

 fusion of the fine wire into globules like common shot. But when the situa- 

 tions of the wires were reversed, so that the smaller wire' was made to form the 

 anode, the ignition became comparatively so feeble as to be incompetent to fuse 

 the fine platina wire. This phenomenon had continued to appear inexplicable, 

 when, during the last winter, it occurred to me that the evolution and combus- 

 tion of the calcium might be the cause of the superior heat produced at the 

 cathode. 



This led to the employment of chlorides in the process of Seebeck, Berzelius, 

 and Pontin, for the production of amalgams from the earths, in which a cathode 

 of mercury, and anode of platina were used. Accordingly, in operating with a 

 deflagrator of three hundred and fifty Cruickshank pairs of seven inches by 

 three, a mercurial amalgam was speedily obtained, which appeared sufficiently 

 imbued with calcium to become speedily buried under a pulverulent stratum 

 of lime, and mercury in a minute state of division. 



Nevertheless, after exposure of the amalgam thus produced to the air, till all 

 the calcium had been separated, and igniting the resulting powder to drive off 

 the adhering mercury, the ratio of the weight of the lime thus obtained, to the 

 mercury with which it had been united, was not over a five hundredth part. 

 With a view to procure an amalgam in which the proportion of calcium should 

 be greater, I was led to devise the following apparatus and process, of which 

 an engraving and description is now laid before the society. 



How far the result of my exertions, subsequently stated, may be considered 

 in advance of the steps previously taken, will be evident from the fact that all 

 the knowledge which exists, respecting the isolation of the metals of the alka- 

 line earths, is due to the experiments and observations of Davy ; and to what 

 point they extended may be learned from the following quotations from the 

 Bakerian lectures of that celebrated chemist. In reference to his efforts to iso- 

 late the radical in question, the distinguished lecturer mentions "that to obtain 



