586 SCIENCE PROGRESS 



judge, improbable. On the other hand, a sufficient concentration 

 of carbon dioxide and water vapour in the primeval atmosphere 

 seems equally improbable. We are thus forced to the con- 

 clusion that so far as we know the initial organic synthesis took 

 place neither in sea-water nor in the ordinary air. 



We reach the same conclusion when we study the further 

 reactions of the primitive carbohydrates with a nitrogen com- 

 pound, such as ammonia or prussic acid. Small quantities of 

 ammonia have been detected in the atmosphere, especially 

 following a violent electric storm, and likewise kindred nitrogen 

 compounds, such as nitric acid. But the quantity of these is 

 excessively slight ; and what is true of the atmosphere is equally 

 true of sea-water. So far as our knowledge extends, therefore, 

 the formation of amino acids seems impossible under any con- 

 ditions which we may imagine in the atmosphere or the ocean, 

 past or present. 



Through consumption by plants, by rock-weathering and the 

 like, enormous quantities of carbon dioxide are annually drawn 

 from the atmosphere, and yet neither historically nor, so far 

 as we may judge, geologically, is there any evidence of the 

 exhaustion of the supply. Apart from the amount returned to 

 the atmosphere by the exhalations of animals and the decay of 

 vegetable matter, practically the sole sources of the atmospheric 

 supply of carbon dioxide are in volcanic action and in gas 

 springs. The quantity given out by the latter is not large in 

 the aggregate, nor are the conditions of organic synthesis to be 

 found in the springs. We are thus led to consider whether 

 such conditions are present in volcanic action. 



Within three or four years our ideas of volcanic chemism 

 have been very radically enlarged, chiefly through the work of 

 Armand Gautier, following up the pioneer work of Moissan, 

 and by the researches of A. Brun. 1 For very obvious reasons 

 our knowledge is as yet tentative, and it is not surprising 

 to find these two able investigators somewhat at variance in 

 their conclusions. But it seems now clear that the role of 

 volcanic action in earthly affairs is vastly more vital and 

 dominating than had previously been supposed. It is not only 

 the chief source of carbon dioxide, and therefore possibly the 

 regulator of terrestrial temperature,- but likewise the chief 

 producer of ammonia or nitrogen compounds (cf. Brun's re- 



1 Loc. cit. 



