28 Mr. Kemp on the Effects of Electricity 



phuroiis acid gas. The odour resembled sulphurous acid ; but as 

 it was not collected, this could not be accurately ascertained. 



A quantity of the liquid sulphurous acid gas being kept in con- 

 tact with sulphur for several days, not the slightest chemical affi- 

 nity seemed to exist between them. It, however, acts on the infe- 

 rior metals. -^ 



Cyanogen. — Exp. I. Dry cyanuret of mercury was placed in a tube, 

 and a platina wire sealed into both ends, as in the former experi- 

 ment. The thick end of the tube was then heated, and the gas liqui- 

 fied in the smaller end. When a quantity had been obtained sufficient 

 to immerse the extremities of the two wires within the tube, it 

 was made to form the circuit of a galvanic battery of 300 pairs of 

 plates, two inches square. No shock was received through it, nor 

 did water or any acid liquid, when placed in the circuit, suffer any 

 decomposition, neither did it affect the galvanometer. Cyanogen 

 is therefore a perfect non-conductor of electricity of this intensity. 



While the liquified cyanogen remained in the circuit, it appear- 

 ed to undergo no decomposition. A few very minute globules of 

 gas arose from both wires ; but this did not appear to depend on 

 electricity, and was evidently not a decomposition of the liquified 

 gas, for it continued after the galvanic circle had been broken. 

 The only apparent cause is, that the platina wires being better 

 conductors of heat than the glass, they might cause the liquid to 

 undergo a slight ebullition at their points. One of the wires 

 was very slightly acted on by the cyanogen. 



Exp. II. In this experiment a tube without the platina wires 

 was used. Dry cyanuret of mercury being placed in the thick 

 end of the tube, cyanogen was generated so as to fill it ; a small roll 

 of litmus paper was then introduced into the smaller end of the 

 tube, and, after the air had been perfectly expelled, it was sealed, 

 thus leaving the litmus paper in contact with the gaseous cyano- 

 gen, on which no change of colour took place. By increasing the 

 temperature at the thick end of the tube, gas was generated in 

 greater quantity, and as the pressure increased, the blue colour of 

 the paper was gradually changed, until the gas became liquified, 

 when it passed into a faint red colour. The tube being afterwards 

 cut, the whole of the liquified cyanogen instantly disappeared, leav- 

 ing the paper perfectly dry, and permanently reddened. Upon 

 the application of an alkali, the original colour of the paper was 

 restored. The cyanogen in this instance seems to have acted the 

 part of an acid, as no moisture was supposed to be present, and 

 consequently neither cyanic nor hydro-cyanic acid could be formed. 

 It may be somewhat difficult to determine where the acidifying 

 principle resides, unless we admit that cyanogen itself, when sub- 

 jected to pressure, and in the liquid state, has this property ; or, 

 as nitrogen, the nature of which is still involved in obscurity, is 

 one of the constituents of cyanogen, it is not at all improbable that 

 the acid property may exist in that substance. 



