REPORT ON GEOPHYSICS 1 79 



able, and yet reliable knowledge in reference to thern is necessary 

 before the phenomena of vulcanism can be put upon a scientific 

 basis. Experiments in laboratories on a small scale show that this 

 work can be done. But the work has never been done upon an ade- 

 quate scale, nor is there any probability that it will be done upon 

 an adequate scale, so that the results can be applied to the history 

 of the earth, until a well equipped geophysical laboratory is con- 

 structed with sufficient funds to operate on a large scale. 



IyOrd Kelvin suggests that in experimental work involving many 

 of these points at least a cubic foot of the melted rock should be 

 taken. Among other Europeans who mention experimental work 

 along these lines as essential are Dr. Ernest Schwarz, of the Geo- 

 logical Commission of the Cape of Good Hope ; Professor L,oewinson- 

 Lessing, of the Polytechnic Institute of St. Petersburg ; Professor 

 Vogt, of Kristiania, and Professor Suess, of Vienna. Also the ne- 

 cessity for this kind of work has been especially emphasized in 

 America by an important group of geologists, including Adams, 

 Cross, Iddings, Kemp, Lane, Pirsson, Washington, and Wolff. 

 Their views upon this and other pressing investigations in geo- 

 physics are set forth in a paper accompanying this report. The 

 carefully systematized, comprehensive plan of work outlined in this 

 paper will be of great assistance to the experimenter if a laboratory 

 is constructed. 



Sufficient work has been done by Morosiewitsch, Doelter, Brun, 

 and others to show that an investigation of the relations of fluid and 

 crystallized rocks will be very fruitful. In America, Professor Carl 

 Barus, under the direction of Clarence King, once began investiga- 

 tions upon fluid rock, but this work was unfortunately discontinued 

 because of lack of funds. Little work along this line is being done 

 anywhere simply because of the lack of properly equipped labora- 

 tories with adequate funds to carry on such necessarily expensive 

 work. If such work be provided for in a geophysical laboratory at 

 the Carnegie Institution, no one can doubt that scientific results of the 

 first order will be obtained. 



(2) Minerals a?id Rocks from Aqueous Solutions. — Another class of 

 investigations is the artificial production of minerals and rocks from 

 aqueous solutions. This involves a study of natural solutions, both 

 those of the sea and those in openings in rocks, in order to determine 

 the conditions under which minerals crystallize from such solutions. 

 Already the study of natural solutions with reference to the crystal- 

 lization of salt and gypsum has been undertaken by Van't Hoff. 



