248 T. S. Hunt on Lithology. 
If we examine the mineral portion under a microscope and 
study its behavior towards reagents, we shall find at least two 
silicates in the meteorite; one of them, like olivine, having the 
formula RO, SiO,, not so easily attacked by acids, and the other 
resembling labradorite, with the formula «R,O, SiO, + yRO 
SiO,. Assuming that the Cr,O, was combined with the FeO 
as chrome iron, the 1°12 Cr,O, will require 0°52 FeO, which 
must be deducted from the 24-47 pr. ct. FeO. Assigning Mg0, 
MnO, NiO, CoO, to the mineral RO?, SiO, andthe Al,O,, CaO, 
to the mineral « R,O, SiO, + yROSIO,, and dividing the FeO 
between them, we have for the mineral portion: 
Chrome iron - - 1-64 pr, ct. Cr,0, FeO 
Olivine, - - 27°43 RO, SiO, i 
Labradorite- - 70°13 Al,0, SiO0,4-4RO Si0, 
99°20 
This will give for the composition of the meteorite; 
Nickel iron (with Co, Mn, and Cu) 48°689 
Sulphid of iron, FeS 7405 
Chrome iron, Cr,O, FeO 0-701 
Schreibersite, (Fe 1:38, Ni 0°67, P 0°115) 1°563 
Olivine, RO, SiO, 11°677 
Labradorite,* (R04, S10, + 4RO Si0,) 29°852 
Tin stone, SnO, 0°189 
100-076 
Calculations were made referring the silicates to hornblende, 
hypersthene, augite, and anorthite, but I omit them in the sum- 
mary as being of a purely theoretical character. The above 18 
believed to give the fair average constitution of this meteorite. 
I must express my obligation to my assistant, Mr. Charles 4, 
Stetefeldt, for skillful aid in hastening the completion of the 
analysis. 
‘New York, Jan. 1st, 1364, 
————— 
Arr. XXVI.—Contributions to Lithology; by T. StERRY HoNt 
M.A., F.R.S.; of the Geological Survey of Canada. 
I. Theoretical Notions—Il. Classification and Nomenclature. : 
In a recent paps on The Chemical and Mineralogical Relations 
ks (this Journal, [2] xxxvi, 214), an ace © 
was made to define the principles which haye presided over 
formation of sedimentary rocks, and to explain the nature an 
conditions of their alteration or metamorphism. That paper 
- 
