EXPLANATION OF THE TABLES. 



TABLE I. — Chromite and Picotite. pp. ii-v. 



This table contains one hundred and twi-nty analyses of chromite and picotite, an-anged in the 

 ascending order of the percentage of chromic oxide. Since the object of the table 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. — Siaerolite. pp. vi-xv. 



This table contains one hundreil and ninety-three analyses of meteoric and terrestrial irons, arranged 

 in the descending order of their percentage of iron. The irons which are supposed to l)e 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 fallen, the supposed meteoric irons, and the terrestrial irons, are distinguished from one 

 another by terms 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 strikuujbi differed in value, 

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

 placed first, but the order of the others stiU remains in the order in wliich they were found. 



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



This table contains twenty-four analyses of meteoric and terrestrial pallasites. 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 ajjproximations only. The analyses are arranged in ascending order 

 of the percentages of silica. 



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



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

 the "Variety" column is given the 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 knowTi are designated by the term Meteorite, and the terrestrial peridotites, whose variety 

 is also unknown, are given the names which the analysts have applied to them. 



The analyses have been arranged in the order of the percentages of silica ; but when more 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, whicli with analyses are to be 

 found in the works and tallies of Partsch, Buchner, Rammelsberg, and Roth, to whicli I am deeply 

 indeljted. 



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 approximation to cor- 

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

 Smith have been particularly unfin-tunate. The recalculations have mostly been made by the aid of 

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



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



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



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