Miscellanies, 363 



having occurred, some months since, to Dr. Hare, that this phenome- 

 non might be due to the evolution and combustion of calcium at the 

 cathode, he proceeded to apply a galvanic deflagrator of three hun- 

 dred and fifty pairs of plates, in the process of Berzelius and Pontin, 

 for preparing the amalgams of the metallic radicals of the earths. 

 The author gives a sketch of the present state of our knowledge in 

 relation to the metallic bases of the alkaline earths, as derived from 

 the experiments of Davy ; adding his own observations, in confirma- 

 tion of the declaration of Davy, that the substances obtained by him 

 from baryta and strontia, were amalgams of their metallic bases, and 

 not the bases themselves ; and, further, that the process employed for 

 obtaining calcium, by Davy, was really incompetent to effect the desi- 

 red result. He then proceeds to describe the peculiar apparatus by 

 which amalgams of barium, strontium and calcium were procured ; 

 the chlorides of the respective alkaline radicals being exposed to gal- 

 vanic action, the cathode being mercury, and the anode a coil of pla- 

 tinum wire. The details of the apparatus cannot be properly under- 

 stood without the figure which accompanies Dr. Hare's communica- 

 tion : its chief peculiarities are the following : 1st. It furnishes the 

 means of keeping the mercury, forming the cathode, at a temperature 

 nearly as low as 32° Fah. 2d. It prevents exposure of the amalgam 

 of the radical, to the direct action of the chlorine from the chloride 

 used. 3d. The alternate and successive, or the simultaneous action 

 of two galvanic deflagrators, was conveniently obtained. 



Dr. Hare states, that after operating with a series of two hundred 

 pairs of plates of one hundred square inches each, for twenty minutes, 

 unaided by these improvements, he had found the proportion of cal- 

 cium to be but one six-hundredth part of the amalgamated mass. 



An apparatus for distilling the amalgam is also described and fig- 

 ured in Dr. Hare's memoir. It consists of an iron alembic, connected 

 with a glass receiver, and an adopter communicating with a reser- 

 voir of hydrogen, and containing chloride of calcium and quick-lime. 

 "Within the alembic, an iron crucible, containing the amalgam, was 

 placed, the crucible being closed by a capsule, in which was a portion 

 of caoutchoucine, and by its cover. Naphtha was poured into the 

 alembic. The air from the apparatus was expelled by hydrogen, de- 

 siccated by passing through the chloride of calcium and quick-lime in 

 the adopter. The distillation was conducted by applying heat prin- 

 cipally to the upper part of the amalgam, to prevent an explosive 

 ebullition. The mercury being distilled off", which requires a bright 

 red heat in expelling the last portions, the metallic radical remained 

 in the crucible. 



