1886.] On the Gaseous Constituents of Meteorites. 549 



Table III. — Relative Hardness or Penetrability of Ice at various 

 Temperatures. 



The steel rod penetrated at -35° F. 0*043 in., and at zero F. 0094 in. 



results are given in Table III. These are the average of very many 

 observations. The ice appeared practically to maintain its almost im- 

 penetrable hardness from —35° F. until about +10° to 20° F., after 

 which its power of resistance to the penetration of the steel rod rapidly 

 decreased with the increase of temperature. It will also be noticed 

 that the relative contraction and dilatation of the ice between the 

 extremes of low temperature employed was considerable. The whole 

 of the experiments were many times repeated to ensure accuracy, and 

 it may be observed that above 20 tons of snow and above 7 tons of 

 salts for freezing mixtures, &c, were consumed in conducting the 

 varied experiments of the investigation. 



XIII. " On the Gaseous Constituents of Meteorites." By 

 Gerrard Ansdell, F.C.S., and Prof. James Dewar, F.R.S. 

 Received June 10, 1886. 

 The nature of the occluded gases which are present to a greater or 

 less extent in all meteorites, whether belonging to the iron, stony, or 

 carbonaceous classes, has engaged the attention of but few chemists. 

 It is, nevertheless, an especially interesting and important subject, 

 owing to the uncertainty which still exists as to the origin of these 

 celestial bodies. 



Graham (" Proc. Roy. Soc," vol. 15 (1867), p. 502, was the first 

 who made any experiments in this direction, when he determined the 

 gases occluded in the Lenarto meteoric iron, which yielded 2 '85 times 

 its volume of gas, "86 per cent, of which was hydrogen, and 4*5 per 



