512 G. P. Merrill — Minor Constituents of Meteorites. 



Tin. — Tin to the amount of 0*17 per cent Sn0 2 was reported* 

 by Stromeyer and Walmstedt as long ago as 1825 as occurring 

 in the olivine of a pallasite. Unfortunately some doubt exists 

 as to whether this was the pallasite of Krasnoyarsk or Steinbach. 

 Rammelsberg in 1884f reported finding 0'08 per cent Sn in 

 the metallic portion of the Klein -Wenden aerolite, and he also 

 tabulates^ 0'5T per cent Sn in the analysis of the Nashville (?), 

 Tennessee, iron. Jackson§ thought to have found 0*063 per 

 cent Sn in an iron from Dakota, while C. A. Joy reported] 

 044 per cent Sn0 2 in the mineral portion of the Atacama 

 pallasite, and Mallet reported§ *002 to '003 per cent Sn in 

 the iron from Staunton, Virginia. Numerous other occur- 

 rences of like small amounts are mentioned in the litera- 

 ture, the copper and tin being frequently undifferentiated. 

 Although not so stated, the inference may be drawn, with the 

 possible exception of that found in the olivine above noted, 

 that tin, if present at all, occurs mainly, if not wholly, as a 

 constituent of the metallic portion of the meteorite. 



The occurrence of this metal has for a long time been 

 regarded as open to question by the writer, notwithstanding 

 the apparent care and skill under which the various analyses 

 had been made. The scepticism was based in part upon the 

 conditions under which the metal occurs in terrestrial rocks, 

 where, as is well known, its presence is limited almost wholly 

 to acidic rocks of the granitic type ; in but two exceptions has 

 it been found to occur in rocks of intermediate (andesitic) type. 

 Genetically then it is fair to assume there is some connection. 

 Among the common mineral associations of terrestrial tin, in 

 the form in which it usually occurs — cassiterite — are, further, 

 several characteristic species, such as fluorite, tourmaline, wolf- 

 ramite, topaz, etc., which are utterly unknown in meteorites. 

 It is of course possible that tin, if present, is in the form of 

 the sulphide — stannite — or as an alloy with iron, but none of 

 the recorded analyses of meteoric sulphides show a trace of the 

 element, nor do analyses of terrestrial irons, as those of Ovifak, 

 Greenland, or the various terrestrial nickel irons as josephinite, 

 awaruite, etc.** 



Titanium. — Rammelsbergff found 0*16 percent titanic oxide 

 (Ti0 2 ) in the insoluble residue from the Juvinas stone. This 

 is the first reported occurrence. Davison reported^ traces of 



*See Rose, Beschreibung u. Eintheilung der Meteoriten, etc., 1864, p. 77. 

 \ Pogg. Ann. , lxii, 449. 



JDie Chemischer Natur der Meteoriten, 1870, p. 146. 

 § This Journal, xxxvi, 260, 1863. 

 I Ibid., xxxvii, 245, 1864. ^[Ibid., ii, 1884. 



** These analyses are brought together in convenient form and discussed 

 on pp. 313-15, 2d ed. of Clarke's Data of Geochemistry. 



ft Pogg. Ann., lxxiii, 585, 1848. ft This Journal, xxii, 59, 1906. 



