PHYSICS OF THE GLOBE. 201 



phere. I have shown, moreover, that the formation of the 

 carbonaceous and bituminous matters in the strata of the 

 earth, all which seem to me to have an organic origin, have 

 required a weight of carbonic acid which far surpasses that 

 of our atmosphere, and moreover would have given place to 

 a very considerable disengagement of oxygen resulting from 

 the deoxidation of carbonic acid and water. It is necessary 

 to admit that this carbonic acid had an extra terrestrial ori- 

 gin. I think we ought to consider our atmosphere as a cos- 

 mic and universal medium, condensed around certain cen- 

 tres of attraction in proportion to their masses and their 

 temperatures, and occupying the whole of interstellar space 

 in a state of extreme rarefaction. From this it will result 

 that the surplus of carbonic acid will be absorbed in equal 

 proportions in the atmospheres of all the celestial bodies, and 

 that at the same time any excess of oxygen disengaged at 

 the surface of our globe will be equally divided among all 

 the celestial bodies. This theory of a universal exchange 

 seems to me to furnish an explanation of the origin of cosmic 



dust." 



Botany and Zoology. 



The influence of atmospheric electricity upon vegetation 

 has been studied by Grandeau, who communicates his results 

 to the Academy of Sciences at Paris, showing that under 

 large trees, under massive shrubbery, and under a coppice 

 covered with verdure, the electric tension of the atmosphere 

 is sensibly zero, while at the same moment, at a iew yards' 

 distance from these conducting bodies, Ave can demonstrate 

 notable quantities of electricity. 



Berthelot communicates to the Paris Academy some inter- 

 esting remarks in reference to the memoir of Grandeau on 

 the Effect of Atmospheric Electricity. He states that he has 

 discovered that the free nitrogen in the air unites with or- 

 ganic matter under the influence of electricity, not only when 

 strong tensions are employed in the experiment, but also with 

 very feeble tensions. He again calls the attention of mete- 

 orologists and farmers to the importance of the continued ac- 

 tion of atmospheric electricity of feeble tension to the fertili- 

 zation of the soil. 



The Influence of Temperature on Vegetation was treated 

 of by Goppert, in which he explains why it is that great ex- 



I 2 



