532 Henry Woodtvard — Address to the Geologists' Association, 



here given, which, show the average of the nmnerical results of all the 

 most trustworthy chemical analyses as calculated by Eeichenbach : — 



Silicon 



... 40-00 



Chi-omium 



. 0-50 



Iron 



... 25-00 



Manganese ... 



. 0-33 



Magnesia .. 



... 20-00 



Sodium 



. 0-33 



AlumiHa ... 



... 2-00 



Other elements 



. 1-34 



Sulphur 



... 2-00 



Oxygen, Hydrogen, 





Nickel 



... 1-50 



and loss... 



. 5-50 



Lime 



... 1-50 





100-00 



" One of the most striking results of the chemistry of meteorites 

 is the discovery made by the late Prof. Graham, that meteoric iron 

 contains, occluded in it, a large amount of hydrogen, which may be 

 regarded as a sample of the atmosphere in which it was formed, and 

 consequently as indicating cosmical conditions totally different from 

 those which obtain on our sphere. It is also strange that the metal 

 nickel, which is comparatively rare on earth, and never occurs in a 

 metallic or alloyed state, should be so constant in meteorites of all 

 classes." ^ 



The study of these remarkable bodies both chemically and micro- 

 scopically has, for many years past, been pursued with marked 

 success by Prof. N. S. Maskelyne, F.E.S., and Dr. Flight, his col- 

 league in the Department of Mineralogy at the British Museum. 



For sixteen years Prof. Maskelyne has striven to make the col- 

 lection of meteorites in our National Museum the most complete in 

 Europe, and at the present time the British Museum can show ex- 

 amples of no less than 297^ diiferent falls, many of which are unique 

 specimens. 



Nor has the perfecting of the collection been the only aim of Prof. 

 Maskelyne ; for he perseveringly represented to the Trustees for many 

 years, and finally succeeded in convincing that Body of the importance 

 and absolute necessity to establish a chemical laboratory, in which 

 rocks and minerals might be analyzed, and their composition accu- 

 rately ascertained. By this means, and having secured the valuable 

 chemical aid of Dr. Flight, some of the results of their joint 

 chemical and crystallographio work has already been communicated 

 to the Eoyal Society by its authors. 



A meteoric stone presents the same difficulties to the investigator 

 which have hitherto rendered the analyses of many fine-grained 

 terrestrial rocks of little value. The difficulty arises from the minute 

 size and imperfect development of the constituents of the rock or 

 meteorite, which precludes in most cases their perfect isolation for 

 examination. In the case of the meteoric stones, however, which 

 have been examined by Prof. Maskelyne and Dr. Flight, the grains 

 were sufficiently large to enable the operator, by long-continued 

 picking over the debris of the meteorite under a magnifying lens, to 

 finally obtain sufficient pure material for examination. A special 

 method had to be devised for the analysis of the silicates finally 



1 D. Forbes, " On Meteorites," Geol. Mag. 1872, Vol. IX. pp. 230-1. 



2 Of these, 183 are "Aerolites" or stone meteorites ; 12 are " Siderolites" or stony 

 irons: and 102 are "Aerosiderites" or iron meteorites. 



