24 MINERALOGY AND LITHOLOGY. 



which have fallen from above, has been often affirmed and often doubted. 

 The subject has, however, received new interest from its proved presence 

 in basaltic rocks, and from the discussion in regard to the origin of the 

 numerous immense masses of iron which have been found in Greenland. 

 My attention was called to this subject by observing a bright particle 

 which was embedded in the midst of a grain of magnetite in a thin sec- 

 tion of the chrysolitic gabbro from Mt. Washington. This particle pos- 

 sessed a lustre so resembling metallic iron, that I tested it with a solution 

 of sulphate of copper, and found that, like metallic iron, it became cov- 

 ered with a film of copper, which proved it to be iron. On testing nu- 

 merous other specimens, I was but twice able to repeat the observation ; 

 hence, though no very great weight can be attached to the experiment, 

 it may be said to exist in these rocks, and, if the undecomposed trap 

 rocks from Waterville, or from the Mt. Washington river, are pulverized, 

 the magnetic constituents withdrawn by a magnet, and these constituents 

 treated with a solution of sulphate of copper, on examining with the 

 microscope, occasionally one will see bits of reduced copper, which is 

 evidence of the presence of metallic iron. The efficacy of this reaction 

 has been doubted ; but my observation of grains of iron, though minute, 

 is sufficient to call the attention of those who may study these rocks in 

 the future to the possibility of finding it in more abundance, and under 

 such circumstances that conclusions can be safely drawn from its occur- 

 rence. 



No meteoric iron has, so far as I know, been found in this state. I 

 might mention that a supposed meteorite, which was found in Concord, 

 has been considered important from the circumstance that it contained 

 no iron, this absence rendering it unique among meteorites. This stone 

 was described by Prof. B. Silliman, Jr., in 1847,* and was shown to con- 

 sist of tersilicate of magnesia and silicate of soda; but although the cir- 

 cumstances of its fall seem to be well authenticated, it is but fair to state 

 that in the cabinet of Yale college, where the specimen is preserved, it is 

 put among the doubtful specimens. The reason of this doubt is, that its 

 very peculiar composition, and its slaggy, artificial look, are thought to 

 weigh seriously against its celestial origin. 



* A»i. jfour. Science, n, vol. 4, p. 353. 



