Deflagrating Carburets, Phosphurets, or Cyanides. 307 



quicklime, enclosed in a porcelain tube heated to incandes- 

 cence,* 



Phosphuret of calcium, when carefully prepared, and, subse- 

 quently, well heated, was found to be an excellent conductor of 

 the voltaic current evolved from the apparatus above mentioned. 

 Hence it was thought expedient to expose it in the circuit of the 

 deflagrator, both in an atmosphere of hydrogen and in vacuo. 

 The volatilization of phosphorus was so copious as to coat nearly 

 all the inner surface of the bell-glass with an opake film, in color 

 resembling that of the oxide of phosphorus, generated by expo- 

 sing this substance under hot water to a current of oxygen. f 



The phosphuret at first contracted in bulk, and finally was, for 

 the most part, volatilized. On the surface of the charcoal, ad- 

 joining the cavity in which the phosphuret had been deflagrated, 

 there was a light pulverulent matter, which, thrown into water, 

 efljervesced, and, when rubbed upon a porcelain tile, appeared to 

 contain metallic spangles, which were oxydized by the conse- 

 quent exposure to atmospheric oxygen. 



In one of my experiments with the apparatus above described, 

 portions of the carbon forming the anode appeared to have un- 

 dergone complete fusion, and to have dropped in globules upon 

 the cathode. When rubbed, these globules had the color and 

 lustre of plumbago, and, by friction on paper, left traces resem- 

 bling those produced by that substance. They were susceptible 

 of reaction neither with chloro-hydric nor with nitric acid, nei- 

 ther separately nor when mixed. They were not in the slightest 

 degree magnetic. 



About 1822, Professor Silliman obtained globules, which were 

 at first considered as fused carbon, but were subsequently found 

 to be depositions of that substance transferred from one electrode 



* After the above mentioned experiments were made, I was led to believe that 

 the compound, obtained as above described by heating lime with bicyanide of mer- 

 cury, contained fulminic acid, or an analogous substance. The mass being dissol- 

 ved in acetic acid, and the filtered solution subjected to nitrate of mercury, a copi- 

 ous white precipitate resulted. This, being desiccated, proved to be a fulminating 

 powder. It exploded, between a hammer and anvil, with the sharp sound of ful- 

 minating silver. 



t The compound usually designated as the phosphuret of calcium consists, accor- 

 ding to Thomson, of one atom of phosphate of lime, as well as two atoms of 

 pure phosphuret. Hence it is easy to see that the oxygen which enters into the 

 constitution of the oxide, deposited, as above mentioned, upon the interior surface 

 of the bell-glass, is derived from the phosphate. 



