Prof. Maskelyne and Dr. Lang's Miner alogical Notes. 49 



brecciated character, — these facts, which the microscope alone 

 reveals, seem to bar the chemist from any complete mechanical 

 separation of the ingredients of many meteorites, whether by the 

 agency of a magnet, or by that of the selection, by the eye and 

 hand, of distinct homogeneous particles*. Still there are cases 

 in which analysis is possible ; in some meteorites, as in that of 

 Pamallee, the minerals are tolerably isolated from each other ; 

 and the fact that the chemist in dealing with such meteorites as 

 those of Chantonnay, Stannern, Luotolax,Bokkevelde, andBishop- 

 ville, is enabled to place each of them as the characteristic 

 member of a group, may furnish ground for the hope that ap- 

 proximate methods may be found for at least determining the 

 nature of the minerals contained in any given meteorite. One 

 such method appears to be furnished by the microscope. A 

 thin transparent section of an aerolite exhibits, under a low power^ 

 in a tolerably characteristic way the minerals of which the aerolite 

 is composed. By comparing these minerals as thus seen and as 

 observed en masse in the specimen with the minerals that pre- 

 dominate in certain well-investigated and, so to say, standard types 

 of meteorite, one soon learns to discriminate between them, and 

 to predicate of any given individual aerolite, with what others 

 it presents mineralogical analogies, though the assignment to 

 each of these minerals of its precise place as a mineral species is 

 in some cases very difficult. Occasionally, however, as in the 

 coarser-grained varieties, one is enabled to discriminate and to 

 separate by mechanical selection for chemical analysis certain 

 mineral ingredients in a state of considerable purity. 



I have sought by these means to determine the lithological 

 character, if I may so call it, of some of the und escribed 

 meteorites in the British Museum. As a nomenclature is much 

 wanted in our language to represent what is so completely ex- 

 pressed by the terms Meteorstein and Meteoreisen in the German, 

 I propose calling the former (the meteoric stone) by the original 

 term Aerolite, the meteoric iron by the term Aerosideritc, and 

 the intermediate varieties (including the Pallasites of Hose), in 

 which the iron is continuous and associated with silicate, by the 

 term Aerosiderolites or Siderolites. The term meteorite would 

 remain a generic expression for the whole. 



* Probably it would be found practicable to determine the iron indi- 

 rectly by the estimation of the hydrogen developed by the treatment of the 

 aerolite with acids, under conditions convenient for collecting that gas. 

 The sulphuretted hydrogen might be estimated at the same time ; and even 

 if it were all calculated as emanating from meteoric pyrites, the ultimate 

 error in the analysis would be less than by a method in which the entire 

 separation of the metallic iron is generally impossible, and the estimation 

 of ferrous oxide therefore as often too high. 



Phil. Mag. S. 4. Vol. 25. No. 165. Jan. 1863. E 



