22 Dr. Walter Flight — History of Meteorites. 



not be found, on examination, to support the theory in question. In 

 addition to the composition of the entire stone, which is to be found 

 below (I.), he gives in his paper the amouuts of each of the bases 

 dissolved in acid during a sulphur determination (see II.). 



I. Total Silicates. II. Bases dissolved III. Bases undissolved 



Oxygen. Oxygen. 



6-92 



Silicic acid 



46-37 











Magnesia 



27-13 .. 



. 11-7 4-68) 





. 15-43 



6-17 



Lime 



2-15 .. 



. 0-56 0-16 



9-55 '.', 



1-59 



0-45 



Iron protoxide... 



22-56 .. 



. 21-2 4-71) 





1-36 



0-30 



Alumina 



0-67 .. 



. 0-14 





,. 0-53 





Loss (Soda?)... 



1-12 











100-00 



Assuming the bases dissolved to be those of an olivine, they would 

 require 17-90 per cent, of silicic acid to form 51-36 per cent, of an 

 olivine of the form FeO, MgO, Si0 2 (like that occurring in the me- 

 teorites of Chateau-Eenard and Kakova), while, tbe undissolved 

 bases with 25*95 per cent, of silicic acid form 45-45 per cent, 

 of a nearly pure magnesian enstatite. There now remain only 

 2 - 52 per cent, of silica, which, with the alumina, and what may 

 possibly be potash, give oxygen ratios, pointing, with more accuracy 

 than might be expected in so small a residue, to about 4 per cent, 

 of what may be a felspar. This method of regarding the con- 

 stitution of the meteorites of Krahenberg and Pultusk has the 

 advantage of assuming the existence in these stones of such 

 meteoric minerals only as have been isolated and clearly identified. — 

 In an elaborate paper on the lithology of this meteorite, Weiss states 

 that lie detected the presence of three silicates, and by a careful study 

 of a fresh surface of the stone, he finds that the grey silicate, which 

 is probably enstatite, occurs in three distinct forms. This is a point 

 of considerable interest, not only as tending to confirm the above 

 calculations, but from the fact that three varieties of a nearly pure 

 magnesian enstatite likewise occur in the Busti aerolite. 



Eeinsch has prepared eighteen microscopic slides of this meteorite, 

 and made very effective pen-and-ink sketches of the more important 

 of them. One shows a remarkable eroded spherule of iron ; the 

 evenly serrated surface is inclosed in a metallic shell, or rather net, 

 so regular are the intervals at which this covering is broken through. 

 Another exhibits spherules traversed by little dykes or veins of a 

 mineral, which in one case is of a purple colour. Others show 

 a beautiful blue mineral, which he suggests may be haiiyne. He 

 directs attention to the presence of magnetic pyrites and nickel-iron 

 in the crust of the meteorite, and contends that, as these minerals 

 would undergo change if exposed in air to a temperature at which 

 the silicates forming the crust fuse, the meteorite must have been 

 covered with a crust before it entered our atmosphere, and he 

 ascribes the fusion to electrical agency, as seen in the perforated 

 rocks (fulgurites ?) of the Lesser Ararat, described by Abich. 



