io6 



Field Columbian Museum — Geology, Vol. III. 



ANALYSES OF OCCLUDED GASES. 



The occluded gases of nine iron meteorites have been determined. 

 These are here shown. 



Name. 



Vols. 



Charlotte 



Cranbourne . . 



Lenarto 



Magura 



Red River. . . 



Rowton 



Shingle Springs 



Staunton 



Tazewell 



2.20 



3-59 

 2.85 



47-13 

 1 .29 

 6.38 

 0.97 

 3-17 

 3'i7 



H. 



CO2 



71.40 



45-79 

 85.68 

 18.19 



76.79 

 77.78 

 68.81 



35-83 

 42.66 



13-30 

 o. 12 



12.56 

 8.59 

 5-15 



13.64 



9-75 

 14.40 



CO. 



15-30 

 31.88 



4.46 

 67-71 



14.62 



7-34 

 12.47 



38-33 

 41-23 



N. 



17.66 

 g.86 

 1-54 



9.72 



5- 



16.09 



1.71 



CH4 



4-55 



Analyst. 



Reference. 



A.W.Wright.. 



W. Flight 



Th. Graham . . . 

 A. W. Wright.. 

 A.W.Wright.. 



W. Flight 



A. W.Wright.. 

 J. W. Mallet ... 

 A.W.Wright.. 



1876, A.J. S. (3), XI, 257 



1882, Ph. Tr. Roy. Soc. Lon- 

 don, 893 896 



1866, Proc. Roy. Soc, Lon- 

 don, XV, 502-503 



1876, op. cit. 



1876, op. cit. 



1882, op. cit. 



1 876, op. cit. 



1871, Proc. Roy. Soc. London, 



XX, 365-370 

 1876, op. cit. 







DISCUSSION OF ANALYSES. 



The most striking feature brought out by the analyses is the rela- 

 tion shown between chemical composition and structure. This seems 

 to be de.finite and general. All the meteorites of a hexahedral struc- 

 ture have a nearly uniform composition, while among the octahedral 

 meteorites, fineness of structure increases with increase of nickel. 

 This conclusion can best be shown by obtaining the averages from the 

 analyses of the different groups, omitting all obviously faulty analyses. 

 The results thus obtained are as follows: 



Class. 



Hexahedrites — 



Coarsest Octahedrites- 



Coarse " 



Medium " 



Fine 



Finest " 



No. of 

 Analyses. 



29 



12 



22 



88 



41 



13 



Width of 

 Lamellae 

 in Millimeters. 



+ 2.5 

 2.0-1.5 

 1.0-0.5 

 0.4-0. 2 

 o. 2 



Per Cent 

 Fe. 



94.12 



93.18 



92.28 



90.64 



90.18 



88.51 



It is worthy of note that these averages are not means between 

 wide limits, but are derived from nearly uniform values. Practically 



