LIFE WITHOUT OXYGEN 131 



Daubeny, 1 is not compatible with the view of a previous great 

 excess of oxygen. 



Further than this, it would seem that in former geologic 

 times, rock weathering and oxidation must have gone on rather 

 more intensely and on a wider scale than at present. It is now 

 increasingly, evident that in the earlier ages at least the land 

 areas were devoid of vegetation. 2 



The continents appear to have been utter deserts, such as 

 are now unknown. We have clear evidence of the existence 

 of an atmosphere and likewise of climatic zones, 3 much as at 

 the present day ; the average temperature was probably much 

 the same as now. 4 These desert conditions would seem to 

 indicate much greater and more frequent precipitation and far 

 more violent winds and storms. ^Eoiian erosion would have 

 been far more prevalent and active than now and the plantless 

 continents would have been swept by enormous dust storms. 

 Under these conditions, oxidation would have gone on at a 

 very intense rate ; so that if, as some writers suppose, a greater 

 excess of oxygen existed in the beginning, this would have 

 been quickly and completely exhausted. We may therefore 

 dismiss the first possibility. 



2. Within the last few years, thanks to the researches of 

 Moissan, 5 Gautier 6 and A. Brun, 7 we have learned something 

 of volcanic chemistry and it may be taken that practically no 

 uncombined oxygen is present in volcanic emanations. On 

 the other hand, we know of vast quantities of hydrogen com- 

 pounds and there is the probability of free hydrogen, so that we 

 have here an agency working for depletion of oxygen rather 

 than the reverse. And plutonic action is probably only volcanic 

 action on a very grand scale. For the rest there seems to be no 

 oxygen free in meteors 8 ; and there is no other visible source 

 of supply. We may therefore dismiss the second possibility. 



1 Cf. his essay on the Geological and Chemical Phenomena of Volcanoes 

 (Oxford, 1824). 



8 Walther, Geschichte d. Erde, 194 and 254 (Leipzig, 1908). 



3 Eckardt, Das Klimaproblem, p. 9 (Braunschweig, 1909). 



4 J. W. Gregory, Climatic Variations (Mexico City, 1906). 

 6 Proc. Roy. Soc. 166, 60, 1896. 



6 Annales des Mines, 316, 9, 1906 ; Revue Scient, 545, 577, 1907. 



7 A. Brun, Arch. d. Sciences de Geneve, 439, 19, 1905 ; 425, 22, 1906 ; February 

 and July 1909. 



8 Clarke, I.e. p. 52. 



