574 DAY AND SHEPHERD WATER AND VOLCANIC ACTIVITY 



tinguished Englishman, long in the service of the native government of 

 the Hawaiian Islands, writes as follows : 



"What we mainly wish to contend for and to impress upon geologists — for 

 re-consideration, at least — is, that it may be a mistake to assert, as is so often 

 done in the most positive manner, that water and steam are inseparably con- 

 nected with volcanic action. On the contrary it would appear that elastic 

 vapors have nothing to do with the liquidity of the Hawaiian basic lavas, and 

 that as a matter of fact they do not seem to come up with them from below, 

 whilst the basic minerals themselves give no indications in the main eruptions, 

 of having been in contact with water, highly susceptible as they are. to such 

 an influence." 



Mr. Green was not only a keen observer of the manner of operation, of 

 the physical forces which participate in the volcanic activity to be seen in 

 the Hawaiian Islands, but his opportunities for studying such phenomena 

 were quite exceptional. His conclusion, supported as it was by many facts 

 of observation, has therefore demanded, and indeed has received, consider- 

 ation at the hands of geologists generally, although until very lately no 

 one has been willing to consider it as having any application to volcanoes 

 outside Hawaii. 



Brux maintains the same View 



More recently Albert Brun, a chemist of Geneva, Switzerland, has 

 offered data 2 (apparently without knowing the work of Green) gathered 

 from a great number of active volcanoes with intent to prove by analysis 

 of the gases which he collected that water plays no part in volcanic activ- 

 ity. His words are as follows (page 249, following a detailed statement 

 of reasons which will be considered below) : 



"II est done parfaitement certain que le volcan paroxysmal n'exhale pas 

 d'eau. La preuve est faite. Le grand panache oJanc est compose de particules 

 solides'et, anhydres." 



"II faut done que la theorie aqueuse disparaisse de la science." 



(The italics and black-faced type are Brun's.) 



Except for these two conspicuous instances, students of vulcanism have 

 generally concluded 3 that water is usually if not always the chief agent in 

 volcanic activity. 



* Recherches sur l'Exhalaison Volcanique. Genera. 1911. 



» G. Poulett Scrope : "Volcanoes." London. 1872. John W. Judd : "Volcanoes, What 

 They Are and What They Teach." London. 1881. James D. Dana : "Characteristics of 

 Volcanoes." New York, 1891. A. Geikie : "Textbook of Geology." vol. i. London. 1903. 

 S. Arrhenius : "Lehrbuch der Cosmischen Physik." Leipzig, 1903. It should perhaps be 

 added that some have expressed the opinion that the importance of water has been over- 

 estimated, without explicit denial of its participation in volcanic activity. (See, for 

 example, J. G. Bornemann : "Ueber Schlakenkegel und Laven, ein Beitrag zur Lehre vom 

 Vulkanismus," Jahrb. d. Kgl. pr. geol. Landesanstalt u. Bergakad, 1887, p. 230.) 



