38 GEOLOGICAL MEMOIRS. 



Baron Reichenbach, in some papers published in Poggendorff's 

 ' Annalen der Physik,' has defended the opinion that meteorites owe 

 their origin to an aggregation of minute globules or crystals ana- 

 logous to those which he supposes to exist in the tails of comets. 

 Haidinger and Kenngott, on the contrary, think these problematic 

 masses to be simply compounds of various mineral substances bear- 

 ing an indubitable analogy with the rocks constituting the solid 

 crust of the terrestrial globe. Baron Reichenbach quotes, in favour 

 of his theory, Mr. Brokedon's experiment with pulverized graphite, 

 which, having been freed by exhaustion from the air that adheres 

 to the surface of any powder, and submitted to moderate compres- 

 sion, was converted to a compact mass like native graphite ; but he 

 omitted to say that, the air having been removed, the experimenter 

 made repeated use on his graphite-powder of a compressing appa- 

 ratus having a force that may be estimated as high as 20,000 cwt. 

 Prof. Schrbtter's ingenious experiments have proved that the action 

 of chemical affinity completely ceases under a temperature of 80° C. 

 below zero ; so that even substances whose chemical union under 

 normal atmospheric temperature is attended with most violent ex- 

 plosions may be safely brought into mutual contact. The tempera- 

 ture of the interplanetary space through which the igneous globes 

 make their way is probably not above — 100°C. (even — 140°C. ac- 

 cording to M. Pouillet) ; so that the fact stated by Schrotter is a 

 weighty objection against Baron Reichenbach's theory, at the same 

 time that it confirms the views of Haidinger and Kenngott. 



[Count M.] 



On the Red Sandstone and Cretaceous Strata of Central Bohemia. 

 By M. Lipold. 



[Proceed. Imp. Geol. Instit. Vienna, January 31, I860.] 



The Red Sandstone formation in the mountain-region of the Circle 

 of Prague is far less complicated than that of N.-E. Bohemia, 

 consisting only of sandstones and shales, the petrographic characters 

 of which, and especially their red tints, distinguish them from the 

 analogous strata of the Carboniferous formation which they overlie 

 everywhere in conformable stratification. The thickness of the red 

 sandstone is but insignificant in comparison with the Carboniferous 

 rocks. Its average dip is 10-20° 1ST. 



The only known organic remains from this sandstone are a few 

 Fish-remains, and from these Prof. Reuss has inferred that the coal- 

 strata of the localities where those remains have been found are 

 subordinate to the red sandstone. 



The Cretaceous group is only represented by its lowermost mem- 

 bers, — the " Quader-Sandstein " (Lower Quader), overlain by the 

 " Planer-Sandstein." The thickness of both does not exceed 60 feet. 

 The strata are horizontal, or with a slight northerly dip. Argillaceous 

 strata, ^ to 5 feet thick, with isolated seams of coal, are frequently 



