294 



EXPERIMENTAL INVESTIGATIONS. 



described (29). The sulphur was now in an atmosphere of 

 pure nitrogen, and this could have been effected in no other 

 way that I am aware of without wetting or forming some 

 deposit on the sulphur. Having connected it in closed circuit 

 with the oxygen tube for twenty-four hours, the galvanometer 

 gave no deflection. A small hoop of iron with a handle was 

 now heated and passed over the tube 

 containing sulphur and nitrogen, the 

 wires being connected with the gal- 

 vanometer (see fig. 2). The result 

 was very striking. I had directed my 

 assistant to watch the galvanometer 

 while I attended to the manipulation. 

 At the same instant he exclaimed 

 that the galvanometer was deflected, 

 and I that the sulphur was melting ; 

 the galvanometer continued deflected 

 during the whole time that the sulphur 

 remained fused, and indeed some 

 time afterwards, until all the sulphur 

 vapour diffused in the nitrogen had become exhausted. The 

 sulphur represented the zinc of an ordinary voltaic com- 

 bination. It was of course impracticable in this case to 

 ascertain the equivalent consumption. This experiment 

 very strikingly exhibits the analogy of sulphur with phos- 

 phorus, and proves that the instant sulphur is fused it 

 becomes a volatile body, as phosphorus is when solid ; 

 the suddenness of its action, coupled with the insoluble 

 character of sulphur, leads to the conclusion that solution in 

 the electrolyte is not a necessary antecedent to voltaic action 

 in the gas battery. Indeed, this might have been deduced 

 from the experiments with phosphorus, as its vapour must 

 have been nearly, if not absolutely insoluble in the electrolyte, 

 or the equivalent results would not have come out so accu- 

 rately ; possibly solution and electrolysis are in these cases 

 synchronous. 



(43.) I was now led to try in the gas battery other sub- 

 stances differing from phosphorus and sulphur, but possessing 

 characters which had hitherto prevented their being used as 



