METEORITES OF NORTH AMERICA. 69 



To render the chladnite soluble in acid, it was fused with four times its weight of carbonate of soda and potash, 

 with a small fragment of caustic potash placed on the top of the mixed powders in the crucible. After fusion, the 

 analysis was proceeded with in the ordinary way; the result of two analyses were as follows: 



1 2 



Silica 60.12 59.83 



Magnesia 39. 45 39. 22 



Peroxide of iron 30 .50 



Soda, with feeble potash and strong lithia reaction 74 .74 



100. 61 100. 29 



The minute quantity of peroxide of iron came from exceedingly fine particles of iron diffused through the minerals, 



and could be seen by a magnifying glass. One separate analysis was made for the soda. 



The constitution of the mineral, as made out from the numbers in analysis 1, is: 



Oxygen 

 Oxygen. ratio. 



Silica 31.22 2 



Magnesia 15. 511 



} 



Soda 19 



corresponding to the formula Mg^i 2 , equivalent to the general formula of pyroxene, R 3 Si 2 . 



The excess of silica obtained by Professor Shepard in his analysis is doubtless due to an imperfect fusion of the 

 mineral with the carbonate of soda, an error easily made, if the precautions I have already mentioned are not attended to. 



"Chladnite" approaches those forms of pyroxene known as white augite, diopside, white coccolite, etc., these 

 last-named minerals having a part of the magnesia replaced by lime. It is identical in composition with enstatite of 

 Kenngott, a pyroxenic mineral from Aloysthal in Moravia. 



From these observations it will be seen that the Bishopville meteoric stone, however different in external charac- 

 teristics from other similar bodies, is, after all, identical with the; great family of pyroxenic meteoric stones. 



Reichenbach s made a number of observations on Bisbopville of wbich the following are 

 the most important. In Study V, pp. 476 and 477, he says: 



A general survey of a hundred different meteoric stones in my possession has shown me that according to outward 

 appearance at least three kinds of fusion crust can be distinguished, namely, those of a glassy luster, those of a dull 

 luster, and those of a sooty appearance. Bishopville belongs to the first or glassy variety. 



Consider now the glassy crust. Here Bishopville affords us a happy example which stands entirely unique among 

 meteorites, and as a rare plant discovered for the first time upon the Alps, rejoices the heart of the botanist, so here a 

 "heaven stone" exalts the soul of the student of meteorites, an entirely colorless, transparent crust clear as water, an 

 aerolite, therefore, covered with a pure glass coating. The entire stone, however, is not covered with such a pure 

 fusion crust since black specks also appear where the stone shows iron oxide from the outside, but many parts of its 

 exterior surface are covered with a colorless, glistening glass. More distinctly than anywhere else, is it to be seen 

 on this meteorite that its crust originates from a simple fusion of the exterior. The stone, which no one would take 

 for a meteoric stone, is in fact entirely snow white, and contains black specks, threads, and nodules, composed of black 

 points crowded together. The white material is a magnesia silicate, transparent under the microscope, interspersed 

 with groups of black iron oxide grains, with here and there a crystal of pyrites. The entire exterior is melted to glass, 

 the silicate to a simple colorless variety, the iron oxide to a black species. 



The data are presented here in their simplicity, without complication with other matters, and we can follow them 

 critically. I possess several large specimens of this beautiful American meteorite (and consider them the jewel of my 

 collection), in which the appearance of the crust is marked by a simplicity never before observed and probably never 

 again to be observed. 



In the case of the black glassy crust, Bishopville again serves as the primary example. On all places where the 

 iron oxide lies in the magnesium silicate, it is black. It has, accordingly, iron-glass, which is black, mingled with 

 silicate glass, which is colorless, coloring it black and thereby forming a scaly, black meteoritic crust, isolated in the 

 silicate glass which covers the colorless, white ground mass. Other meteorites possess no such large, pure aggregations 

 of white ground mass, they are mostly mixed interiorly with iron oxide, metallic iron, dark-colored augite, and horn- 

 blende and are gray. 



In Study XIII, pp. 359-60, he describes the structure of Bishopville as follows: 



Bishopville appears at first sight composed of an amorphous ground mass and innumerable larger and smaller lumps 

 and masses imbedded therein. These consist of granules of the size of poppy seeds, roundish, elliptical, and of all 

 sorts of irregular forms, even to course crumbs, interspersed without visible order, usually closely compacted together 

 in balls, and cemented in place by the ground mass. Most of them, especially the larger ones, show a foliated structure, 

 are sectile and brittle along the lines of these folia, and have a luster upon the cleavage surfaces, They are much 

 purer than the ground mass, entirely white, with here and there a heterogeneous spot scarcely visible to the naked eye. 

 They lend themselves to analysis better than the substance of other meteorites, and retain their properties, but unfortu- 

 nately the substance is dearer than gold, and accordingly is but little available for extensive.study. Under the micro- 



