324 EXPERIMENTS RELATIVE TO METEORITES. 



eminent cliemists, it results tliat meteorites have presented no simple body for- 

 eign to om- globe. The elements which have thus far been recognized in them 

 with certainty are 22 in number, and in the following enumeration are arranged 

 very nearly in an order corresponding to the progressive diminntion of their im- 

 portance : Iron is absolutely constant, as well in a metallic state as in that of 

 a sulphuret ; in the stony masses it also occurs as an oxide, entering into differ- 

 ent combinations of the protoxide. Magnesium, is met with very generall}' in 

 the state of a silicate ; it has been recognized also in the constitution of the phos- 

 phiuets mentioned above. Silicium gives rise to the silicates which constitute 

 the principal mass of most meteorites. Oxygen is always present in the stony 

 part of these bodies. Is'ickel^ as has been seen, is the principal accom}>animent 

 of the iron. Cobalt, without being in as great proportion, is almost as constant. 

 The same is the case with chrome, which is found in the stones in the state of 

 chromated mm. Manganese has been often mentioned. Titanium is much 

 more rare. Tin and copper have been discovered by Berzelius. Alumina exists 

 in a certain number of meteorites, in the state of multiple silicates; so likewise 

 do piotassium, sodium, and calcium. Arsenic occurs in the peridot of the iron 

 meteorite of Atacama. Phospjhoriis presents itself chiefly in the state of phos- 

 phurets, and sometimes of phosphates. Nitrogen, discovered by- Berzelius in 

 the carbonaceous meteorite of Alais, has been detected anew in the ferruginous 

 meteorite of Lenarto by M. Boussingault. Sulphur very frequently forms sul- 

 phurets. Traces of chlorine are distinguishable in certain iron meteorites by 

 the chloruret of iron which it produces after a time, and which falls into deliques- 

 cence. Carbon is found in iron meteorites, either as graphite or combined with 

 the metal as a carburet. It exists also in the carbonaceous meteorites , in com- 

 bination with oxygen and hydrogeu, and in one such meteorite it has l)een met 

 with in the state of a carbonate. Hydrogen also forms a part of the carbon- 

 aceous meteorites ; quite recently M. Graham has given notice of its existence 

 in the iron of Lenarto, in which nitrogen had been already detected. 



COMBINATIONS COMMON TO METEORITES AND THE TEERESTRIAL GLOBE. 



In the number of the combinations which these different simple bodies affect in 

 meteorites, there are several which are found in the mineralogical species of the 

 earth. Such are peridot, pyroxene and the anorthite feldspar, chromated iron, 

 magnetic pjyritcs^ and oxydulated iron ; the last is singularly rare. Crraphite, 

 and probably water, may also be cited among minerals common to meteorites 

 and the terrestrial globe. 



Jiloreover, certain meteorites present mineralogical species associated after the 

 same manner as in certain terrestrial rocks. It is thus that the stone of Juvinas 

 approximates extremely to certain lavas of Iceland; that the stone of Ohassigny 

 offers all the characters of the peridot of the earth, with grains of chromated ii'on 

 disseminated, exactly as in the peridotic rock called dunite, recently discovered 

 in New Zealand; while the carbonaceous meteorites recall, in certain respects, 

 some of our carbonaceous combustibles. 



MINERALS PECULIAR TO METEORITES. 



On the other hand, several mmeralogical species are peculiar to meteorites, 

 especially nickeliferous native iron, tht' p]wsphuret of iran and of nicliel, {schreib- 

 ersite,) and the sulphuret of iron [tro'Uite). 



