284 R. T. HILL — PELE AND THE WINDWARD ARCHIPELAGO 



This gaseous theory of Arrhenius, so revolutionary to previous concep- 

 tions of the earth's interior, and which hitherto has been recognized in 

 America only by the students of mining geology, has lately received the 

 approval of Sir Archibald Geikie. This recognized leader of geological 

 thought, in the newest edition of his " Text-book of Geology," 1903, re- 

 ceived while the present paper is being written, generously states that 



" For some of the latest views regarding the nature and origin of volcanic action 

 we are indebted to Professor Arrhenius, of Stockholm, whose observations on the 

 probable condition of the earth's interior have been already cited, and who, bring- 

 ing the results of modern physical and chemical research to a consideration of the 

 subject, confirms what has been the growing belief on the part of geologists in 

 regard to this part of their science. . . . The aspect thus presented of the 

 probable constitution of the interior of our planet appears to accord well with the 

 geological requirements. Not only does it furnish an explanation of the charac- 

 teristics of earthquake movements, but, as Professer Arrhenius cogently shows, it 

 helps us to understand some of the more difficult problems of volcanic action." 



Thus Arrhenius gives science the first tangible hypothesis with which 

 to combat the assertion of the crustalists that the heat and materials of 

 vulcanism are generated within the subcutaneous layers of the earth by 

 crustal load and movements. We can now see that within the earth's 

 centrum is contained matter so intensely hot that its temperature may 

 be classed as celestial. This matter contains all the elements of the 

 crust metals, gases, and rocks ; possesses the potentiality to escape from 

 the interior through the crust to the surface, and the power to assume 

 an infinite variety of forms, combinations, and conditions as it ap- 

 proaches and reaches the surface. 



Source of the ivater of vulcanism. — While Arrhenius' theory has given us 

 a more reasonable working hypothesis than any hitherto possessed con- 

 cerning the interior, the source of water of vulcanism still remained the 

 bone of contention. The crustalist views largely centered around the 

 belief that the water of volcanoes is superficial and admitted to the magma 

 from above, thereby creating the steam of expansion and explosion. 



Thoughtful investigators have also lately been finding many reasons 

 for disbelieving that the inletting waters of the oceans have been the 

 exciting cause of vulcanism, and have boldly suggested that the water 

 of volcanoes, instead of being contributed by the oceans, is derived from 

 the gases of the earth's interior. They have even inquired if the oceans — 

 the great aqueous envelope of the globe — have not been made by con- 

 tributions from the condensation of volcanic gases from its great cooling, 

 shrinking interior protomagma. 



An objection long since pointed out by Geikie to " the constant influx 

 of water from the surface is the difficulty of conceiving that water should 

 descend at all against the expansive force within. Experience in deep 



