131 



When the circuit in a galvanic battery, the deflagrator of the author, 

 was completed through a saturated solution of chloride of calcium, 

 the anode being formed by a coarse, and the cathode by a fine plati- 

 num wire, the latter was rapidly fused, while, when the situation of 

 the wires was reversed, the ignition was comparatively feeble. It 

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

 non might be <lue 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 confirmation 

 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 obtain- 

 ing calcium, by Davy, was really incompetent to effect the desired 

 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 galvanic 

 action, the cathode being mercury, and the anode a coil of platinum 

 wire. The details of the apparatus cannot be properly understood 

 without the figure which accompanies Dr. Hare's communication : 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 

 figured in Dr. Hare's memoir. It consists of an iron alembic, con- 

 nected with a glass receiver, and an adopter communicating with a 

 reservoir 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 



