G. P. Mar rill — Minor Constituents of Meteorites. 523 



0*03 per cent NiO, and 0*03 per cent V 2 3 , with no BaO or 

 SrO in a websterite from Cecil County, Maryland. A dunite 

 from the Tulameen River in British Columbia yielded the same 

 authority no TiO„ BaO, Zr0 2 or SrO ; only traces of P 5 5 , but 

 0*10 per cent of JSiO. Neither copper nor tin is reported in 

 any instance. On the other hand there are found in the mete- 

 oric peridotites both copper and tin (?), together with platinum 

 and vanadium. The last named, as is well known, has been 

 shown to be a widely distributed element, though occurring in 

 minute quantities and in the less siliceous rocks.* In rocks 

 rich in olivine and ferrous iron (i. e. peridotite) it is, however, 

 so far as available analyses show, wholly lacking. Although 

 platinum is known to occur even in commercial quantities in 

 some peridotites, Duparc's analysesf failed to reveal it : this is 

 unquestionably owing to the small amount of rock operated 

 upon. The lack of more definite results on meteoric perido- 

 tites may doubtless be ascribed to the same reason. 



Silica or silicon is not infrequently reported in analyses of 

 meteoric iron in amounts rarely exceeding 0*2 of one per cent. 

 The condition under which the element exists is in some cases 

 at least problematical. Hunt and Silliman, in describing the 

 iron of Lockport (Cambria), N. Y.,J refer to a reddish brown 

 residue obtained by them as being " either silica with a trace 

 of carbon or silicon," which last, they add, " Prof. Shepard has 

 already shown to exist in the Oswego iron." Prof. Shepard, 

 however, in his paper simply tabulates his results as " Silicon 

 0*20 per cent" and does not commit himself as to the condition 

 under which the element may exist. Prof. Mallet, in his anal- 

 ysis of the Staunton, Va., iron, gives O067 per cent, 0*061 and 

 # 056 per cent Si0 2 , but adds by way of explanation, " some of 

 it (i. e., the Si) seems to have in reality existed as a silicate of 

 iron." § Cohen, in his Meteoritenkunde (p. 55), refers the Ca, 

 Mg, Al, K and N very properly to the silicate minerals, and 

 adds, " Das gleiche gilt wo hi auch in der Kegel fur Silicium ; 

 doch fuhrte Winkler in metallischen Theil von Rittersgriin 

 gefundene Kieselsaure auf Silicium zuriick, welches mitEisen 

 verbunden war, und nahm das Vorhandensein eines Silicium - 

 eisen von der Formel Fe 2 Si an, dessen Menge er fur das Nickel- 

 eisen zu 0*329 per cent berechnete." W. Tassin in 1907 

 announced verbally in an informal communication before the 

 National Academy of Sciences " the discovery of elemental 

 silicon" in the meteoric iron of Casas Grandes, Mexico, inci- 

 dentally claiming it as " the first announcement of the occur- 

 rence of this element in nature." With reference to these 



* Bull. 167, U. S. Geol. Surv., 1900, p. 49. Also Clarke, The Data of Geo- 

 chemistry, p. 



+ Arch. Sci. Phys. Nat., xxxi, 194. 



% This Journal, ii, 374, 1846. § Ibid., ii, 1871. 



