SIDKROLITK. (Jj 



masses exist which properly should coirie iinrlor the species siderolite. How- 

 ever, it is an open question, and it \vill prohuhly reinaui so until the<e 

 deposits can be studied witii the view of ascertaining the facts bearing upon 

 tlieir origin, unbiassed by any preconceived theories of that origin. 



The native iron found in Greenland may properly be mentioned here, 

 as it is possibly a portion of the earth's metallic core brought to the surface 

 by the associated basalt. The iron is in large masses associated with basaltic 

 rocks, as well as in fine grains intimately mixed with the baso.lt itself and 

 taking the place of the ordinary iron ores that generally occur in that rock. 

 It occurs with schreibersite, pyrrhotite (troilite) graphite, and magnetite, the 

 same as native iron commonly docs in meteorites. On etching, the Wid- 

 mannstattian figures are produced, and thus this iron shows characters that 

 have usually been regarded as exclusively belonging to meteoric irons. 

 These figures are produced even on the little grains, six to seven millimeters 

 in diameter, occurring in the basalt. Whether the Greenland iron came from 

 the interior of the earth as metallic iron, as the writer thinks most probable, 

 or was produced by the reducing agency of carbon on some ores of iron, as 

 maintained by Steenstrup and Smith, there appears at present no doubt that 

 it is of terrestrial origin. 



Of the laro;e number of metallic siderolites that have been described, 

 but very few are known to be of meteoric origin, only some seven having 

 been seen to fall ; while the localities in which so many occur — in moun- 

 tainous districts, and in regions in which eruptive action has been intense 

 — are such that in regard to many, doubt must exist regarding their cos- 

 mic origin.* Indeed, if they are truly of meteoric origin, there is a most 

 remarkable concurrence of localities in which telluric iron would naturally 

 occur, if at all, and the places in which iron in relatively large amounts 

 has fallen. 



Tt would seem that chemical analysis should not be made the sole judge 

 regarding the origin of these numerous supposed meteorites. It would 

 appear to be necessary that a petrographical or geological study of the 

 localities in which these bodies are found should be made ; and they ought 

 to be reixarded as doubtful meteorites, unless the circumstances of tlieir 

 occurrence preclude tlieir terrestrial origin. That no attempt has been 

 made, as a rule, to ascertain the origin of these masses of iron, beyond 

 chemical tests, will be seen from the following: — 



* The conditions under wliich tlie Baliia siderolite was lound renders it not improbable that this is of 

 similar origin witli (lie Ovifak iron. See A. F. Mornay, riiil. Tmns., 1816, pp. 270-2S3. 



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