306 Description of an Apparatus for 



ing the voltaic circuit, my apparatus and mode of manipulation 

 will be interesting to chemists. 



An equivalent of quicklime, made with great care from pure 

 crystallized spar, was well mingled, by trituration, with an equiv- 

 alent and a half of bicyanide of mercury, and was then enclo- 

 sed within a covered porcelain crucible. The crucible was in- 

 cluded within an iron alembic, such as has been described by me 

 in this volume, as employed for the isolation of metallic radicals. 

 (See page 300.) 



The whole was exposed to heat approaching to redness. In 

 two experiments the residual mass had such a weight as would 

 result from the union of an equivalent of cyanogen with an 

 equivalent of calcium. 



A similar mixture being made, and, in like manner, enclosed 

 in the crucible and alembic, it was subjected to a white heat. 

 The apparatus being refrigerated, the residual mass was transfer- 

 red to a dry glass phial with a ground stopper. 



A portion of the compound thus obtained and preserved was 

 placed upon the parallelepiped of charcoal, which was made to form 

 the cathode of two deflagrators of one hundred pairs, each of one 

 hundred square inches of zinc surface, co-operating as one series. 



In the next place, the cavity of the bell-glass was filled with 

 hydrogen, by the process already described, and the cone of char- 

 coal being so connected with the positive end of the series as to 

 be prepared to perform the office of an anode, was brought into 

 contact with the compound to be deflagrated. These arrange- 

 ments being accomplished, and the circuit completed by throw- 

 ing the acid upon the plates, the most intense ignition took place. 



The compound proved to be an excellent conductor ; and du- 

 ring its deflagration emitted a most beautiful purple light, which 

 was too vivid for more than a transient endurance by an eye un- 

 protected by deep-colored glasses. After the compound was ad- 

 judged to be sufficiently deflagrated, and time had been allowed 

 for refrigeration, on lifting the receiver, minute masses were 

 found upon the coal, which had a metallic appearance, and which, 

 when moistened, produced an effluvium, of which the smell was 

 like that which had been observed to be generated by the silicu- 

 ret of potassium. 



Similar results had been attained by the deflagration, in a like 

 manner, of a compound procured by passing cyanogen over 



