HORNES ON MAMMALIAN REMAINS IN BROWN COAL. 41 



posed even more easily and in greater quantity than the carbonate of 

 lime. The more facile decomposition of carbonate of magnesia is 

 shown by the fact that even boiling water by itself separates the car- 

 bonic acid from it, this not being the case with the carbonated oxy- 

 dule of iron. When, therefore, either limestone, dolomite, or iron- 

 stone-spar occur at a depth beneath the earth's surface where boiling- 

 water-heat exists, and water has access, carbonic acid will be driven 

 off from these carbonated salts. 



The Soffioni on Monte-Cerboli, &c. in Tuscany, discharging boil- 

 ing-hot vapours from crevices in the limestone, must come from a 

 depth where boiling heat exists, and it is very probable that the ac- 

 companying carbonic acid arises from the above-mentioned causes. 

 The same must be admitted for the carbonic acid discharged so abun- 

 dantly in the neighbourhood of the Laacher-See, in the volcanic Eifel, 

 and in other places. These exhalations proceed from the clay-slate 

 formation. According to the laws of the increase of temperature to- 

 wards the centre of our earth, we may calculate that boiling heat 

 exists at a depth of about 8600' in these districts, and this depth is 

 certainly within the limits of the clay-slate formation, which is calcu- 

 lated to be at least a mile [German] thick. Calcareous beds (trans- 

 ition limestone) and quartzose rocks occur at this depth, waters pene- 

 trate thereto, and carbonic acid is separated from the limestone as in 

 the above-mentioned experiments. 



To account therefore for the origin of carbonic acid exhalations, we 

 need no more assume that the focus must be where red heat exists, 

 which presupposes a depth of at least five miles [German] ; for the 

 clay-slate or any other sedimentary formation may be the seat of the 

 evolution of the gas, since only in the moderate depth of about half 

 a mile [German] the materials required are present. [T. R. J.] 



Account of Mammalian Remains found in the Brown Coal of 

 Bribir, near Novi, on the Kroatian Coast. By Dr. Moritz 



HoRNES. 



[Leonh. u. v. Bronn's Jahrb. f. Miner. 1849, p. 759, and Mittheil. Freund. 

 Naturw. Wien, 1848, iv. pp. 83-86.] 



The Vindoler valley extends parallel with the coast of the Gulf of 

 Quarnero A\ German miles from south-east to north-west. Both 

 of its sides, occasionally very steep, consist of sandstone and clay- 

 slate ; these rocks, on one side, are overlaid with limestone, which 

 elsewhere appears to have been washed away by the floods that ex- 

 cavated the valley. In this valley have been found two kinds of 

 coal ; glance-coal, pure, thick, very shining, brittle, and exhibiting 

 a transition from brown- to stone-coal ; and brown-coal with distinct 

 woody texture, dull, earthy, and brown. Probably the former be- 

 longs to the "Wiener sandstone, Macigno, or, according to Morlot's 

 latest researches in Istria, to the Keuper ; whilst the latter is ter- 

 tiary. The former lies on a very hard sandstone ; and the latter, 



