EXPERIMENTS RELATIVE TO METEORITES. 325 



CHAPTER III. 



SYNTHESIS OF METEORITES. — § T. SYXTHRTIC EXPKRIMENTS RELATIVE TO 



METEORITES. 



"While the species common to meteorites and to the teirestrial globe disclose 

 influences which have <ij)erate(l equally in these two oi'ders of deposits, the 

 species proper to raeteoriies indicate other and peculiar influences, an attentive 

 examination of which leads to useful indicati<»ns iii re<^ard to the mode of form- 

 ation of these last bodies. Be it remarked, however, that we lay aside abso- 

 lutely all consideration of the cause by which meteontes are brought into our 

 atmosphere, in order to confine ourselves solely to the peculiarities of their 

 strnc/turc and composition. 



It has been sometimes thought that meteorites became cr\'stallized in our 

 atmosphere by the process of cooling undergone therein. Now, nothing of the 

 kind exists. These planetary bodies reach us, it is true, in an incandescent 

 state ; but this incandescence never attains the interior of the pieces, even when 

 they are of very small dimensions. Hence it follows that the interior condition 

 of the mass is, to all appearance, identically what it was in cosmic space. 



It has seemed to me that the moment was opportune for verifying by syn- 

 thetic experiments the numerous ideas which analysis has furnished on the con- 

 stitution of meteorites.* It might be hoped, in eftect, that experimental syn- 

 thesis would not render less service in this field of study than in that of miner- 

 als and terrestrial rocks. 



EERRUGIXOUS METEORITES. 



We have seen above what is remarkable in the structure of these bodies, and 

 what is due at once to the crystallization of the whole mass and to a segregation of 

 like material. In seeking fo reproduce that structure, I first melted the meteoric 

 iron of Caille (Var) in a cement of alumina, avoiding the use of charcoal, which 

 would have combined with it. The mass, after fusion, presented at its surface 

 and in its fracture a distinct crystallization ; but it no longer offered the brilliant 

 lines which were so clearly delineated in the natural state. Perhaps the result 

 had been more satisfactory if the cooling could have been efTected in a very slow 

 manner. It is [)roper to add, moreover, that the iron meteorites themselves do 

 not always present the geometric regularity just indicated. There are those in 

 which tlu? i)hosphuret is isolated under rounded forms, (piite irregular and often 

 indistinct. 



Another series of experiments had for its object to associate soft iron with each 

 of the principal substances which accompany it in the meteorites, particularly 

 with nickel, silicium, sulphur, and ])liosphorus. By associating soft iron with 

 nickel, with jirotosulphuret of iron, and with silicium, masses were obtained of 

 a dendritic or extremely crystalline structure, but ollering no true segregation com- 

 parable to that of the ferruginous meteorites. It is otherwise if we melt soft iron 

 with the addition of phosphuret of iron in a pioportion which has been carried 

 from 2 to 5 and 10 per 100. We then see isolated on the polished surface which 

 has undergone the action of the acid a more brilliant and resistant substance 

 which perfectly resembles that of the iron meteorites, excepting a less degree of 

 regularity in the figure. A still better result has been obtained by introducing 

 nick(d at the same time with the phosphuret of iron, and espeinally by operating 

 on consideral)l(Mnasses, the weight of which reaches froui two to seven kilograms. 

 In the midst of dendritic figures of a remarkable regularity, and which, accord- 



* "Couiptes rendus," t. Ixii, pp. '200, 3G0, GG'J. " Bullutiu de la socicto gfeologique de 

 France," '4d series, t. xxiii, p. 2'Jl, 18GG. 



