556 



Mr. G. Ansdell and Prof. J. Dewar. [June 10, 



collected was only 0'17 times that of the graphite, containing 95*0 per 

 cent, of carbonic acid. It is therefore evident that the large quantity 

 of gas occluded in celestial graphites cannot be explained by any 

 special absorptive power of this variety of carbon. In view of the 

 large and varying percentages of marsh-gas in the gaseous products 

 of all these graphites, it appeared to us of especial interest to 

 ascertain whether the quantity of marsh-gas extracted coincided in 

 any way with the hydrogen obtained by their combustion. We there- 

 fore submitted all the samples to ultimate analysis, with the following 

 results : — 







Percentage composition. 







f 



Hydrogen. 



Carbon. 



Ash. 



Celestial graphite . 



. .. Oil 



76-10 



23-50 



Borrodale 



3? • 



. .. 0-11 



94-76 



4-85 



Siberian 



JJ • 



. .. 0-17 



79-07 



20-00 



Ceylon 



?} 



0-017 



90-90 



9-08 



Unknown 



5J 



. . . 0-246 



78-51 



21-26 



These analyses do not seem to point to any very definite conclusion 

 as to the origin of the marsh-gas. The unknown graphite, which 

 contains the largest percentage of marsh-gas, certainly comes out far 

 the highest in hydrogen, and the hydrogen in the Ceylon graphite 

 also bears a certain relation to the small quantity of marsh-gas it 

 contains, but the first three samples are very similar to each other in 

 the amount of hydrogen they contain. 



In order to get some further insight into the origin of this marsh- 

 gas in the celestial graphite, about 2 grams of the original nodule 

 were very finely ground up and digested for several hoars with 

 strong nitric acid. After being thoroughly washed from every trace 

 of nitric acid and dried at 110° C, it was again submitted to analysis, 

 with the result that the amount of hydrogen remained exactly the 

 same as before, proving that it existed in the form of some very 

 stable compound in the graphite. 



To clear up this matter still further, about 10 grams of the original 

 nodule were digested with pure ether in the way described by Law- 

 rence Smith for extracting the hydrocarbon-like bodies. It was 

 allowed to stand for twenty-four hours with excess of ether, and then 

 filtered, and washed with more ether. The graphite thus treated was 

 dried at 110° C, and the gases extracted from it. 



For the purpose of comparing one of the terrestrial graphites with 

 the above in regard to its behaviour with ether, the specimen of 

 unknown origin was selected, as yielding the largest quantity of 

 marsh-gas. The residue, after digestion with ether, was dried, and 

 the gases pumped out as before. 



It will be seen that by this treatment with ether the volume of gas 



