of Olivine, Peridot, Sfc. 368 



mitted afresh to a careful examination ; at the same time that 

 the more accurate knowledge of their constituents is so nearly 

 related to the researches concerning the chemical constitution 

 of meteoric stones ; for, as is well known, the basis of most of 

 these remarkable substances seems to consist of a mineral 

 similar to the olivine species. — Engaged in an express chemical 

 investigation of meteoric iron and meteoric stones. Professor 

 Stromeyer found also occasion to attend to this object, and 

 now laid before the Royal Society of Gottingen, in the treatise 

 which has been mentioned, his analyses of these minerals. 



First, the investigations relating to the olivine are communi- 

 cated. For these, an extremely pure and perfectly undecayed 

 olivine from the basalts of the Vogelberg at Giessen was used 

 in preference; for which Professor Stromeyer was indebted to 

 the kindness of Professor Wernekinck at Giessen and Dr. Thi- 

 lenius at Weilburg. Its specific gravity was found to be, in one 

 experiment at 45-5° F, and barom. 29*095 in. = 3-3324 ; and in 

 another experiment at 67*55° F. and barom. 29*410 in. = 

 3*3386. 



According to the mean of three analyses conducted with 

 the greatest care, and differing from one another very incon- 

 siderably, this olivine seems to be composed of 



Silica 40*09 



Magnesia 50*49 



Protoxide of ii*on 8*17 



Oxide of nickel 0*37 



Oxide of manganese 0*20 



Alumina 0*19 



99*51 

 As, however, the component proportions of the olivine in 

 this analysis differ very considerably from the result which 

 Klaproth obtained, this investigation was repeated with an- 

 other olivine from Bohemia, just as pure and well preserved, 

 which occurs in the basalt at Casalthof. 



The analysis of this produced a result perfectly correspond- 

 ing with the former. 



From 100 parts of this Bohemian olivine, whose specific gra^ 

 vity was at 49*1° F. and barom. 29*646 in. = 3*3445, were 

 extracted 



Silica 40*45 



Magnesia 50*67 



Protoxide of iron 8*07 



Oxide of nickel 0*33 



Oxide of manganese 0*18 



Alumina 0*19 



99*89 

 Z z 2 TIjc 



