ADVISORY committee; ON GKOPHYSICS 65 



[/. H. van^t Hoff to Mr. Walcott, June 22^ igo2.'\ 



CharIvOTTENburg,/z^w<? 22, igo2. 

 Dear Sir : 



In reply to your letter of May 5, wherein I am honored by 

 your consulting me on plans for research in geophysics, I express 

 as my conviction that an investigation in that direction might prove 

 of the highest value, if made in a systematic way and continued 

 for some years. 



The special problem, which, I mean, deserves attention, is the 

 physical chemistry of high temperatures applied to the chief con- 

 stituents of the earth's crust, silicates in the first instance. To 

 express myself more clearly, I add that two great problems concern- 

 ing geophysics may in the present state of our knowledge be 

 solved, viz., the evaporation of complex solutions, which have 

 produced systemic deposits, such as salt layers, etc. ; and secondly, 

 the cooling down of molten masses, that have produced the volcanic 

 and plutonic formations. 



With the first problem, by far the easier one as regards apparatus, 

 etc., I have been occupied for more than six years, and a series of 

 twenty-six publications in the Annals of the Prussian Academy of 

 Sciences (i 897-1902) shows how far these researches have been 

 carried out. 



By the same post I send two abstracts, one by Armstsong, the 

 other forming part of the lectures I delivered at Chicago last sum- 

 mer. It is my opinion that, guided by the indications obtained, the 

 second problem, concerning the formation of plutonic and volcanic 

 products, may be successfully taken up, but to pursue it in a sys- 

 tematic way the co-operation of different forces, furnished with 

 special facilities for research extending over some years, is needed, 

 such as can only be realized by an Institution like that newly founded 

 by Mr. Carnegie. I may add, however, in favor of the project, 

 that, when once an installation for high temperature research, with 

 the special aim pointed out, has been established, many problems 

 of the highest importance might be successfully studied with the 

 same means. I suggest, moreover, that the use of Niagara Falls as 

 a source of electric heat for the above purpose be taken into 

 consideration. 



Respectfully yours, 



J. H. van't Hoff. 



