36 Professor Bronn on some Geological and Physical 



evolved by the fixed carbon may be necessary for maintain- 

 ing the draft ; for, let us suppose the coke to be pure carbon, 

 we never could expect that in practice it would evaporate to 

 the full extent of what it is calculated to do, for, in that case, 

 no allowance whatever would be made for loss of heat to the 

 walls of the furnace, and more particularly, for that, which it 

 is well known always passes off with the gaseous products of 

 combustion up the chimney. 



On some Geological and Physical Considerations connected 

 with certain portions of the Glacier Theory of M. Agassiz. 

 By Professor H. G. Bronn of Heidelberg.. 



The remains of fossil elephants seem to present an incon- 

 gruity in the theory. As these remains are contained in the 

 diluvial strata elevated by the Alps, the animals must have 

 lived and perished along with their contemporaries at the 

 period of the formation of these strata ; and, as they occur in 

 a state of good preservation in the Siberian ice and frozen 

 soil, it must also be assumed, that these animals were still in 

 existence and were suddenly annihilated and enveloped in 

 ice at the time of the suddenly occurring cold of the ice pe- 

 riod, therefore not till after the formation of the diluvium, 

 which could not have been likewise caused by this cold. 



With this subject we must here connect the questions, — if it 

 be actually susceptible of proof, from these remains of ele- 

 phants, that such a refrigeration of the temperature of Siberia 

 took place at that time ? — if, at the time when the elephants 

 existed, it was actually so much warmer in that region ? — and 

 if the supposed cooling must have taken place so suddenly ? 



In the first place, the occurrence of living species of ele- 

 phants in warmer regions is no proof that extinct species re- 

 quired as warm a climate. At the present day, we still find 

 various species of the genera Ursus, Canis, Cervus, and Bos, 

 distributed throughout every zone. Cuvier, also, in reference 

 to the former climate of Siberia, directs attention to the fact, 

 that the species of elephants enveloped in the Siberian ice 

 had by no means a naked skin, but was provided with a cover- 



