EXPLANATION OF THE TABLES. 



TABLE L— Chromite aud Picotite. 



pp. ll-V. 



This table contains one hundred and twenty analyses of chromite and picotite, arranged in the 

 ascending order of the percentage of chromic oxide. Since the object of the talkie is to show the mutual 

 relations of the two minerals, and their variations, many of the analyses given of chromite are of the more 

 impure forms, — commercial ores (0- 



TABLE II. — Siderolite. pp. vi-xv. 



This table contains one hundred and ninety-three analyses of meteoric and terrestiial irons, arran^efl 

 in the descending order of their percentage of iron. Tlic irons whicli are su])posed to lie meteorites, but 

 which have not been known to fall, have been marked by an interrogation point jilaced after the term 

 Meteorite. No variety names proper occur in this species ; but for convenience the meteoric irons 

 known to have fallai, the supposed meteoric irons, and the terrestrial irons, are distinguished from one 

 another by terras placed in the " Variety " column. 



When several analyses are given for the same locality, no attempt is made to arrange them beyond 

 this : the analysis first found in the search for the analyses is placed first, and the others follow in 

 the order in which they were seen; except in cases in which the analyses slrikinffhf <UJftre/l in value, 

 owing either to internal evidence or to tlie reputation for accuracy of tlie analyst ; then the best is 

 placed first, but the order of the others still remains in the order in which they were found. 



TABLE in. — Pallasite. pp. xvi, xvii. 



This table contains twenty-fo;ir analyses of meteoric and terrestrial pallasitcs. The doubtful meteor- 

 ites are designated as in the preceding table, while the terrestrial forms are given their proper variety 

 name, — Cumberlandite. But few of these analyses are accurate exponents of the constitution of the 

 rock mass, the majority being rough approximations only. The analyses are arranged in ascending order 

 of the percentages of silica. 



TABLE IV. — Peridotite. pp. xviii-xxxi. 



This table contains two hundred and forty-four analyses of terrestrial and meteoric peridotites. In 

 the "Variety" column is given tht name of the variety so far as known, and when the specimen is a 

 meteorite it has been designated by an asterisk prefixed to the variety name. The meteorites whose 

 variety is not known are designated by the term Meteorite, and the terrestrial i)eridotites, whose variety 

 is also unknown, are given the names which the analj'sts have applied to them. 



The analyses have been arranged in the order of the percentages of silica ; but wlien mo'-e than one 

 exists for the same locality, they have been arranged as stated for Table II. 



The specific gravities in this and the other tables have been taken from any available source, when 

 the analyst has given none ; but it has been found impracticable to designate the source from which 

 they were obtained, although many are from C. Rumler's determinations, which with analysts are to V>e 

 found in the works and tables of Partsch, Buchner, Kammelsberg, and Roth, to which I am deeply 

 indebted. 



Many analyses of meteoric forms have been made in such a manner that no determination of the 

 complete chemical constitution is possible, owing to the omission of necessary data for recalculation, and 

 all such have been omitted. Many others have been recalculated with more or less apjiroximation to cor- 

 rectness, varying according to the data ; matters in which the numerous analyses of Dr. J. Lawrence 

 Smith have been particularly unfortunate. Tlie recalculations have mostly been made by the aid of 

 a four-place table of logarithms, and tlierefore partake of its imperfections. 



TABLE V. — Part I. The Meteoric Basalts, pp. xxxii, xxxiii. 



This part contains tliirty-one analyses, arranged in order of their percentages of silica. 



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