1886.] 



on Becent Besearches on Meteorites. 



647 



that although the celestial graphite contains a considerable amount, 

 it is very much less than that yielded by the terrestrial samples. 



A few tentative experiments were made to ascertain the absorbing 

 power for gases of this celestial graphite. For this purpose dry car- 

 bonic acid, marsh-gas, and hydrogen were respectively drawn through 

 the tube containing the previously exhausted graphite for twelve 

 hours in the cold, the gases being pumped out at a low red heat after 

 each treatment with the dry gas. After the carbonic acid treatment 

 the volume of gas collected was only 1 • 1 times that of the graphite, 

 containing 98*4 per cent, of carbonic acid ; after the marsh-gas the 

 volume of the gas was only 0*9 that of the graphite, containing 94*1 

 per cent, carbonic acid ; and after the hydrogen the volume of the gas 

 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 of especial interest to ascertain 

 whether the quantity of marsh-gas extracted coincided in any way 

 with the hydrogen obtained by their combustion. All the samples 

 were therefore submitted to ultimate analysis, with the following 

 results : — 



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 hours 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. 



