EXPERIMENTS RELATIVE TO METEORITES. 



323 



of hcing perfectly clear, been rainy, or Bimply covered with clouds, tlirong'li wliich 

 tLose stones would have had to pass, such is their constitution that only a viscous 

 mud would have remained to be gathered, similar to that which, on some occa- 

 sions, has been observed to fall.* 



The study of the meteorite of Orgneil shows, finally, that meteorite dust may 

 he combustible, and contribute to incandescence V)v its oxidation. In view of 

 these diSercnt facts, it cannot l)c questioned that great atteiition should 1)0 paid 

 to the fall of atmospheric dust. It miglit be well, after the explosion of bolides, 

 to seek in the air for this pulverulent matter, b}^ all the means which science now 

 places at our disposal, and to examine it, especially, with a view to detecting the 

 presence of nickel. 



■ GascouH mdeorifes, (mentioned by way of suggestion). Does the celestial 

 space ever furnish gaseous matter? This we know not; but without speaking 

 of shooting stars, it is not impossible that certain meteorites, or the bodies from 

 which they are detached, are j)rovidcd with an atmosphere. Whether this be so 

 or not, for the sake of completeness, and in order to call attention to the point, 

 we include gaseous meteorites in otu' list. 



§ 2. CLASSIFICATION OF METEOHITES. 



After indicating the different types to which meteorites may be referred, it is 

 proper to express their relations by means of a classification. That which we 

 here })resent, though otherwise very sim{)le, has reriuired the invention of a cer- 

 tain number of names, which, as indicated in th($ following talde, will be found 

 convenient. It comprises only groups and sub-groups; but each of the latter 

 embraces several different types which need not be specified in so compendious a 

 review: 



Solid and Coherent Meteorites, 



SfDERITES.- 

 Mfteoritea 

 containing 

 iron in a 

 metallic 

 State 



Not oontc'.n- 



oontc'.n- > 

 g stony \ 

 alter. . . . ) 



I. HOLOSIDEKOUS 



SUB-6R0UP. EXAMPLES. DENSITIES. 

 „..Charcas 7.0 to 8.0 



Containing 

 at the same 

 time iron-; 

 and stony 

 matter 



f The iron pre- 

 Kents ilHelf 

 asacontin- ( 

 uoUH maDH.J 



ASIDERITES. 

 Mfteoriteg 

 Dot con- 

 t a i n i n g 

 iron in a 

 metal lie 

 Btate 



l„., 



Syssiderous Rittersgrtin. 7.1 to 7.8 



The iron pre-] 



iron pre-"! 

 Bents itstlf ( III. SpORADO-SID- 



in disueni 

 at«(l grains. 



in-f- 

 ns. J 



' Polysiderous. — ] 

 Quant ityol' iron 

 tousidmablo. . . ' 



OUgo$idcrous. — 

 Quantity ot'iron 

 Biuall 



Sierra de 

 Chaco. 



G. 5 to 7. 



3. 1 to 3. 8 



Ortjptosiderous — 

 Tliu iron 



perceptible tofjuvinas 

 Bight J 



I Chaseigny.. 3. ; 



3. to 3. 8 



.IV. AsiDEROns... ^ Orgueil 1.9 to 3.6 



§ 3. COMPOSITION OF METEORITES COMPARED WITH TERRESTRIAL ROCKS. — 



SIMPLE BODIES. 



From some hundreds of analyses, which have been conducted by the most 



* Thus, in Lusace, 8tb March, 179ti, there was seen to full, after the explosion of a bolide, 

 a mass which was viscous, bluish, imd probably carbonaceous. 



