which are evolved in Goal-Minea. 333 



tion of such a compownd stands, without doubt, in connection 

 with the decomposition of the carburetted hydrogen gas. 



Wlience, then, does it arise, that the results of my experi- 

 ment differ sojnuch from those obtained by Dalton ? Henry 

 states, that it is only moist carburetted hydrogen gas which can 

 be expanded to double its volume, by means of electric sparks. 

 Afterwards, however, he remarks,* that this is also the case 

 with extremely dry gas. The dissimilarity of results cannot, 

 therefore, be accounted for, from Dalton having probably 

 electrified moist gas, while I operated on perfectly dry gas. 

 I can hardly believe that a more powerful effect can be pro- 

 duced by electricity than by red heat. As I did not at all 

 succeed in completely decomposing pit-gas by means of red 

 lieat, although I repeated the experiment so frequently, the 

 results of the English chemist still seem to me somewhat 

 puzzling. 



§ VIII. Phonomena exhibited by Pit-Gas with Sulphuric Acid. 



A bottle of pit-gas was transmitted through a tube 1 foot 

 in length, filled with chloride of calcium, and then through 

 Liebig's absorbing apparatus, which was filled with concen- 

 trated sulphuric acid. The acid was not rendered in the least 

 brown, and was not increased in weight. The gas, therefore, 

 contained no non-permanent gas which is absorbed by sulphuric 

 acid. Hence, it follows, that the substance which had render- 

 ed the sulphuric acid brown in a former experiment (§ 6.), did not 

 exist originally in the gas, but was only produced after the ap- 

 plication of heat. 



The absence of a gas capable of being absorbed by sulphu- 

 ric acid, does not support the opinion that the inflammable 

 pit-gases can be products of a sort of dry distillation. 

 (To be concluded in next number.) 



* Gilbert's Annalen., vol. ii. p. 194. 

 t Idem. vol. xxxvi. p. 298. 



VOL. XXIX* NO. LVIir. OCTOBER 1840, 



