W. Skey, — On the Evolution of Sulphur from Carbon, 391 



carbon is free from sulphur ; but if we allow tlie carbon a few seconds contact 

 with sulphuretted hydrogen, wash it, connect as before, and even use pure 

 hydrochloric acid as the exciting fluid, a great quantity of this gas is given 

 off at the surface of such carbon. 



These experiments are very simple ones, and appear to be decisive — at least 

 they clearly show, when taken in connection with the prevalence of sulphuretted 

 hydrogen in the air and the absorptive power of carbon for it, that the 

 evolution of this gas described by Mr. Highton does not necessitate the 

 decomposition of sulphuric acid. But, in answer to this, Mr. Highton asserts 

 that " if any one will take a porous jar with a plate of carbon in the middle 

 packed round with broken pieces of carbon, form it into a battery with 

 amalgamated zinc, dilute sulphuric acid for an electrolyte, and set it to work 

 through say twenty Ohms for twelve hours, I think he will find the evolution 

 of sulphuretted hydrogen too great to be thus accounted for." 



Now, I contend that if the suggestions conveyed in this paragraph were 

 carried out, their only effect would be to encumber the case, and further, that 

 the opinion Mr. Highton arrives at, being based upon hypothetical results 

 merely, has not that force or certainty proper to any opinion the object of 

 which is to controvert one affirmed to rest upon experimental evidence, as 

 this does. If Mr. Highton is so sure of his ground that he thinks he can 

 afford to exercise his courtesy by toning down in this manner what he 

 conceives to be truth, I thank him for this manifestation towards me, but, 

 while appreciating the kindly motive itself, I must express a wish that he had 

 been more specific j and I may state here that my only reasons for delaying so 

 long as I have in answering this letter have been the lack of this quality in it, 

 and the hopes which I entertained that the question in dispute between us 

 might ere this have been taken up by some one who would be unbiassed to 

 either side by previous utterance or thought of his with regard to it. 



However, to go back to the allegations I then made in reference to the 

 paragraph itself, I would ask Mr. Highton what necessity, if any, is there to 

 pile the carbon pole around with pieces of carbon ? If juxtaposition of pieces 

 of carbon with the carbon pole fundamentally affects the character of the 

 results in regard to the question at issue, then I submit that Mr. Highton is 

 leading me off from this question to the consideration of a phenomenon 

 I have neither contemplated or disputed, which is, besides, new to chemistry, 

 and so one that Mr. Highton, being the first to indicate, has the honourable 

 right to be the first to investigate. 



This modification by Mr. Highton would certainly have the tendency to 

 largely increase the evolution of the gas in question and so to increase its 

 duration, but still I contend this would not be to a greater extent than can be 

 accounted for upon other grounds than those Mr. Highton has taken up. It 



