FOREIGN CORRESPONDENCE. 



287 



2.46 ; lime, 0.81 ; oxidulated manganese, 0.39 ; soda, 1.92 ; potash, 

 0.56 ; graphite, 0.15 ; nickel, 0.20 ; and sulphur, a trace. 



Hydrochloric acid reduced it into undecomposed silicates, 43.3, and 

 decomposed silicates, 56.7 ; these last giving, by means of further 

 operations, a per centage of silica, 19.5 ; magnesia, 11.2 ; oxidulated 

 iron, 24.4 ; nickel, 0.2 ; lime, 0.7 ; and sulphur, a trace ; so that they 

 may be considered to be a mineral substance analogous to olivine, Tvith 

 a very large proportion of oxide of iron, as occurs in many other 

 meteorites. The per centage of the insoluble portion is : silica, 

 50.49; magnesia, 36.84 ; lime, 1.88; alumina, 5.71; soda, 4.45; and 

 potash, 0.59 ; representing, according to Sartorius von Walters- 

 hausen, an aggregate of 82.17 of magnesian wollastonite, and 17. 

 of anorthite, with the difference only that these two minerals as 

 they generally occur are decomposable by acids. 



Mr. Haidioger added some remarks on the theory of meteorites, 

 tending to prove that the opinion of the formation of meteorites by 

 immediate aggregation of the gaseous or extremely subtle matters 

 dispersed through the cosmic spaces, is, in all proloability, very far 

 from the truth. A temperature of from 50"" to 91^ cent, (as calculated 

 to exist within these spaces) is a veiy unfavourable condition for the 

 crystalline arrangement of material atoms. It is more probable that 

 a reaction from the interior to the surface is going on within an 

 already formed aggregate of substance, which, by mutual and opposite 

 pressure, and with the assistance of heat (a natm-al consequence of 

 it), shapes the component particles into a stone-like compound. 

 Subsequent eruptions may then have detached and thrown off minor 

 portions of the whole, and of these some reach the surface of the 

 ^lobe. Humboldt, in his Cosmos," alludes to the improbability of a 

 sometimes highly developed crystallizing process going on during the 

 brief time of the passage of meteorites across the ten-estrial atmo- 

 sphere. 



On the Fossil Mammalia of the Vienna Tertiary Strata. By Professor 

 E. SuESS. Read he fore the Imperial Academy of Sciences, Vienna, 

 June,\^5d). Communicated hy Qo^^T Marschall. 



The supposed complete identity of the faunae of the Leitha lime- 

 stone, the CongeriEe-beds, and the sands of Belvedere (Vienna), does 

 not really exist, although a few species are found throughout the 

 "whole series. The species of Hippotheriurn and Sus peculiar to the 

 Congeriae-beds and the Belvedere sands are nowhere co-existent with 

 the Fsepho-phorus and the Cervidce of the Leitha limestone. Binotlieriurn 

 seems to be common to both these faunae. The remains of mastodons, 

 long ago identified with the species, fi^om Eppelsheim, described by 

 Professor Kaup (for instance, the ramus of a lower jaw, found by 

 Count Breunner, near Kremms, in Lower Austria, and figured by 

 Cuvier as Mastodon angustidens, the two rami of a lower jaw, and 



