18 Dr. Walter Flight*— History of Meteorites. . 



peasants who were coming out of church ; one struck the ice close 

 to a man who was fishing on the Malar Larsta-Viken, and after 

 digging a hole three or four inches deep, rebounded ; when picked 

 up, it was still warm. 



The stones vary greatly in weight, from 21bs. to 017 gramme 

 (about 2^ grains). The smallest have the same structure and thick- 

 ness of crust as the largest, and are in fact little complete meteorites. 

 Such diminutive stones have not hitherto been noticed, and should 

 be sought for at future aerolitic falls. 



The exterior of the stones is black ; the interior bright grey, and 

 sufficiently porous to cling to the tongue. Though the structure of 

 these meteorites is so loose that they break in pieces when thrown 

 with the hand against the floor or frozen ground, it is a remarkable 

 fact that nearly all the specimens which have been collected fell 

 intact, and some of the heavier stones which struck the ice of the 

 Larsta-Viken failed to penetrate it, although the thickness was only 

 a few inches on New Year's Day. This explains in some degree the 

 statements of eye-witnesses as to their remarkably small downward 

 velocity. 



In appearance they resemble very closely the meteorites of Aussun 

 and Clarac, Haute Garonne (9th December, 1858). They have been 

 examined by Nordenskjold, who so arranges the results of his 

 analyses that he finds them to be composed of : 20 per cent, nickel- 

 iron (chamoisite, Fe g Ni), with some schreibersite and rather less than 

 one per cent, of chromite ; a variable amount of troilite (iron mono- 

 sulphide) ; a trace of carbon, probably in the form of a hydrocarbon; 

 10 per cent, of labradorite ; 37 per cent, of olivine; and 23 per cent. 

 of 'shepardite.' 



Two great difficulties, however, are presented by this explanation 

 of the constitution of the Hessle meteorites. It is not only assumed 

 that a basic silicate, like olivine, and a sesquisilicate, or acid 

 silicate, like ' shepardite,' exist in intimate association in the same 

 rock-mass, but it necessitates the retention as a mineral species of 

 this very ' shepardite ' which the researches of Dr. L. Smith on the 

 Bishopville stone have shown to be no other than a pure magnesian 

 enstatite (MgO,Si0 2 ). 



In the following table are given : under I. the oxygen ratios of 

 the mean of the total constituents from three analyses, after the nickel- 

 iron had been removed by mercury chloride in one case, and by the 

 magnet in another; under II. the oxygen ratios of acid and bases 

 of silicate broken up by acid ; and under III. the difference between 

 I. and II., or the oxygen ratios of acid and bases of silicate un- 

 affected by acid. 



I. Total. II. Soluble. III. Insoluble. 



Silicic acid ... 



26-45 ., 



.. 10-78 





15-67 



Iron protoxide 



2-971 . 



.. 1-858 



\ 



1-113 \ 



4-261 | 



Magnesia 



11-82 . 



.. 7-559 





Lime 



0-748 ., 



.. 0-219 



U-976 



... 0-529 y-7-352 



Alumina 



1431 .. 



. 0-03 





1-401 



Soda 



0-358 ., 



;. o-3i 



) 



0-048 ) 



