GROWTH OF EXPERIMENTAL SCIENCE '- 185 



Time does not permit me to do more than merely enumerate a few of 

 these. 



Among the best known of these is the work of Fouque and Levy/* 

 Moro&ewicz/^ and others on the synthesis of igneous rocks and the eluci- 

 dation of the processes and conditions under which the crystallization of 

 these rockg go forward. 



Th€! studies of the melting points of the fock-formirig minerals, their 

 solubilities in silicate magmas, of eutectic mixtures, and magmatic differ- 

 €!ntiation, carried on by the staff of the Geophysical Laboratory in Wash- 

 ington, by Poelter-^ and his pupils, by Vogt^' and others. 



The investigations which have been made in recent years into the true 

 nature, mineralogical composition, and chemical relations of that great 

 series of artificial rocks which are daily coming to be of greater impor- 

 tance in the arts of peace and war — the cements. 



The extended investigations which are now being carried on in the' 

 Geophysical Laboratory, in elucidation of the field studies of Graten,- 

 into the composition of copper ores and the problems of secondary enrich- 

 ment — investigations which are not only of great significance from the 

 standpoint of pure science, but which promise to have a far-reaching 

 economic value. 



As examples of experimentation in very different fields, the work by 

 Gilbert^^ and Murphy on the transportation of debris by running water^ 

 that of Andree,^^ Lang and Peterson"*' on the laws of geyser action, and 

 that by Daubree^^ on the development of joints and fractures by torsion 

 may be instanced. 



The Future op experimental Geology 



Looking into the future, it is clear that the great conquests which await 

 experimental geology are to be won through the application of accurate' 

 measurement to all experimental work. We are passing from the quali- 

 tative to the quantitative in experimental geology. To carry out such 

 exact investigations in the regions of high temperature and great pres- 

 sure, by which alone we can hope to unlock the secrets of the earth's crust, 

 will require not only able workers — men of skill, resource, and imagina- 



24 Synthese des Min^raux et des Roches. Paris, 1882. 



25 Tscher. Mitt, 19, 1, 1899. 



26 Haftdbuch der Mineralchemie. Dresden, 1912. 

 8'^ Die;^41ikatschmelzlosungen. Christiania, 1903. 



28 U. ?6. (^Qft!. Survey, Professional Paper No. 86, 1914;. 



20 NQwe,s JpflU^. fur Min., Bd. 2, 1893. 



30 Neues JajiifJ). ifflr Min., Bd. 2, 1889. 



3^J^\^|ides Synthfi^^ues de G6ol®gie ExpSi-lmejitale,. 



