76 Notices of Memoirs — Daubree, 



appears the most simple and natural, In examining a certain num- 

 ber of these masses it has been thought convenient by some to 

 establish a third, or intermediate division, to which the names of 

 Mesosiderites, Lithosiderites, or of Siderolites, have been given. How- 

 ever convenient may appear this latter division, it presents some 

 difficulties when we examine the passages which connect the extreme 

 terms of the series ; viz., from that of massive iron to that of the 

 stone exempt from it. It is thus that certain specimens have been 

 placed by some in the intermediate division, and by others in the 

 third, or in the first division. In not admitting this division there 

 are also difficulties, particularly for the meteorites, such as that of 

 Pallas, where the stony grains are disseminated amongst the metallic 

 mass, and which thus forms the first link between the irons and the 

 stones. In placing the collection of meteorites in the new cabinet of 

 the museum of the Jardin des Plantes, at Paris, M. Daubree has 

 replaced the purely chronological arrangement formerly adopted, by 

 a classification which enables one to perceive the relations of this 

 series of planetary bodies. 



M. Daubree has adopted four great di^dsions, to each of which he 

 has given particular names, which, although somewhat new and 

 complicated, are intended to facilitate the study of these bodies. 



It is exclusively the solid, or coherent meteorites which are 

 classified, leaving out of consideration the gaseous or liquid matters 

 which may accompany the solid masses, and also the falls of powder 

 which have sometimes been recognised. Metallic iron, which is ab- 

 sent in all terrestrial rocks [?] , and is found in nearly all meteorites, 

 has afforded the most natural basis for the great divisions, both as to 

 its arrangement and mode of association with the stony matter, as 

 by its relative proportion. The term Siderites is proposed for the 

 meteorites containing metallic iron, and Asiderites for those without 

 it. The Siderites may be deprived of all stony matter, or contain it 

 in the most minute quantity ; these masses comprise the group 

 Holosideres, coiTcsponding to the meteoric irons properly so-called ; 

 as, for example, the masses of Caille and Charcas. When the 

 Siderites contain silicates, the iron may exist as a continuous mass, 

 similar to a sponge, the stony matter occupying the vacuities ; or 

 the iron may occur in more or less large grains, disseminated in the 

 stony matrix. In the first case the Siderites belong to the division 

 Syssideres ; in the second to that of Sporadosideres. The Syssideres 

 may contain the stony matter in two states, corresponding to those 

 indicated for the iron ; either in distinct, disseminated grains, as is 

 observed in the iron of Pallas, in that of Atacama, in that of Tuczon,^ 

 etc. ; or in the form of a continuous mass, entangled as a network 

 with the iron, similar to that of the iron of Eittersgriin. The 

 division of Sporadosideres contains the greatest number of known 

 meteorites. For the convenience of study, M. Daubree has divided 

 them into three sub-groups, under the names of Polysideres, Oligo- 



^ The specimen from Tuczon, in the British Museum, presented by the town- 

 authorities of San Francisco, 1863, shows that this meteorite should be classed with 

 the Siderites.— J , M. 



