300 



Fusion- Structures in Meteorites. 



XX, Fig. 8 ; while the third section exhibits a different pic- 

 ture. The one part, consisting of the fused crust, presents the 

 strikingly crystalline appearance of the first section (No. 13) ; 

 this portion polarizes nicely. Then follows a dark, black mar- 

 gin, and then comes the gradual transition to the grey, stony 

 part, which is of a decidedly different nature. 



It hence appears that the great rise of temperature to which 

 a meteorite is exposed in its travels thi'ough the earth's atmo- 

 sphere, — a temperature sufficiently high to jjroduce the phe- 

 nomena of light, frequently very brilliant, accompanying its 

 fall, — exerts its influence only over a comparatively small por- 

 tion of the body, and hence would not effect any material modi- 

 fication or change in the original structure of the meteorite. 



The chemical composition of meteorites has frequently been 

 investigated, and numerous analj'ses of such meteorites are re- 

 corded. Moreover, it is no easy matter to take one or two of 

 these analyses and present them as "typical," for as already re- 

 marked, they range through all proj)ortions of composition of 

 mineral and metal. 



Some few analyses have already been given ; here will only 

 be cited the analysis of the meteorite which fell at Orgueil, 

 France, May 14, 1864. 



The examination Avas made by Messrs. Pisani and Cloez, 

 and first published in the Oomptes Rendues of 1864 ; but the 

 figures here given are from a corrected paper sent by M. Pisani 

 to Mr. Phipson,* as the notice first issued contained several 

 misprints. 



Cloez. 





Pisani. 





Hygroscopic Water, - 



5.957 







Ammonia, 



- 0.098 



Substance dried at 110° C. 





Humus, 



6.027 







Combined Water, - 



- 7.345 







Sulphur, - - . . 



4.369 



Sulphur, - - - . 



5.75 



Chlorine, 



- 0.073 



Chlorine, 



- 0.08 



Phosphorus, 



traces. 



Hyposulphurous Acid, 



0.53 



Sulphuric Acid, - 



- 2.195 



Sulphuric Acid, 



- 1.54 



Silica, ... 



- 24.475 



Silica, - . . . 



26.08 



Meteors, Aerolites and Falling Stars ; 1867, page 116. 



