1886.] Prof. Dewar on Becent Besearches on Meteorites. 641 



WEEKLY EVENING MEETING, 



Friday, June 11, 1886. 



Henry Pollock, Esq. Treasurer and Vice-President, in the Chair. 



Professor Dewar, M.A. F.R.S. M.B.I. 



Becent Besearches on Meteorites. 



Professor Dewar explained that Mr. Gerrard Ansdell and himself 

 had been engaged in an examination into the gaseous constituents of 

 meteorites, and he proposed this evening to abstract the results of the 

 investigation, which had been laid before the Eoyal Society. 



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. Eoy. Soc. vol. xv. (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 

 cent, carbonic oxide. He was followed in 1872 by Wohler (Pogg. 

 Ann. vol. cxlvi. p. 297) and Berthelot (Compt. Eend. vol. Ixxiv. 

 pp. 48, 119), who estimated approximately the gases contained in the 

 Greenland Ovifak iron. These gases consisted of about equal parts 

 of carbonic acid and carbonic oxide ; the celestial origin of this iron 

 is, however, very doubtful. 



In the same year (1872) the American chemist. Mallet (Proc. 

 Roy. Soc. vol. XX. p. 365), made a very complete determination of 

 the gases occluded by the Augusta Co., Virginia, meteoric iron, 

 which, however, differed very considerably from Graham's results. 

 He obtained an amount of gas equal to 3' 17 times the volume of the 

 iron, made up of 85 • 83 per cent, of hydrogen, 38 • 33 per cent, carbonic 

 oxide, 9 * 75 per cent, of carbonic acid, and 16*09 per cent, of nitrogen. 



Wright and Lawrence Smith followed Mallet, and our present 

 knowledge of this interesting subject is principally due to these 

 American chemists. They have taken advantage of the numerous 

 meteoric masses which have fallen from time to time throughout 

 America, and which can easily be obtained in sufficient quantity for 

 complete and accurate observations on their gaseous constituents. 



Wright contributed several papers to the ' American Journal ' in 

 1875 and 1876, and, according to his analyses, the total volume of 

 gas occluded and the composition of the same differs considerably in 

 the two principal classes of meteorites. He found the total volume 



