328 



EXPERIMENTS RELATIVE TO METEORITES. 



white, furnished by the Iherzolite of Piiules (in the Pyrenees) yield on analysis 

 in lOOpcOrts:* 



est 

 the 



Certain basaltic peridots, mingled with pyroxene and en statite, offer the strong 

 t resemblance to Iherzolite, and, under the action of fire, deport themselves ii 

 e same manner. For instance, the n«edles ol)taiued by the fusion of the peri 



dot of Beyssac (Haute-Loire) give in 100 part 



in 



peri- 



Silex 



Magnesium 



Protoxide of iron 



56.4 



39.0 



3.0 



98.4 



Oxygen. 



28 

 15 



Ratio. 



By the addition of a certain quantity of silex, the proportion of bisilicate or 

 enstatite may bo augmented at will, and produce those mixtm-es which form the 

 transition j'rom peridot to Iherzolite. The same bisilicate is generated along the 

 ■walls of the crucible by borrowing silex from them. I will remark here that by 

 adding to peri(h)t 15 per 100 of silex, the quantity necessary for its conversion 

 into enstatite, and then melting it in the midst of charcoal, we obtain a mass cov- 

 ered on its surface with flattened rectangular octahedrons of the form which 

 belongs to peridot, wdiile the interior consists of a iil)r(jus mass unalterable by acids, 

 A\hich has the characters of enstatite. An identical fact takes place in the fusion 

 of certain meteorites. 



The minerals, which had been first submitted, as above, to simple fusion, 

 ■were next subjected to the same action in the presence of a reductive influence. 

 For this })urpose charcoal disposed as brasque in a crucible was first ado[>toil. 

 The same results as before were thus reached, with this difference only, that tiie 

 iron, wdiich was combined in the silicate, is reduced to the metallic state. It 

 separates into precipi tate and granules or remains disseminated in the undecomposed 

 silicate in microscopic grains separable l)y the magnetized bar ; at the same time, 

 the portion of silicic acid corresjjonding to this ircm contributes to augment the 

 ]»roportion of the bisilicate. All the iron, however, is not reduced to the metal- 

 lic state ; a part remains in combination in the silicate ; and it is worthy of 

 reniark, that the green coloration, so characteristic of peridot or olivine, gives 

 place to a general gray tint analogous to that of meteorites of the common type. 



This product of the reduction and fusion of peridotic rocks greatly resembles, 

 therefore, that of meteorites treated in the same manner. The analogy subsists, 

 in a striking manner, for the stony part ; it equally subsists for the metallic part. 

 In eiiect, the metallic iron, proceeding from the redaction of the })eridot of Laii- 

 geac, contains O.G per 100, or O.OOG of nickel. That furnished by the Iherzolite 

 of Lherz likewise contains nickel and phosphuret in addition. I have obtained 



* These different ehemical analyses were made by M. Stanislas Meunier, assistant natuialiet 

 at the nmseuiii of iiaiural history. 



