22 CARNEGIE INSTITUTION OF WASHINGTON. 



of the pure minerals concerned, but has already begun the 

 processes of analysis and synthesis which are leading to exten- 

 sive additions to our knowledge of rock and mineral forma- 

 tions found in the earth's crust. In illustration of these 

 processes the Director's report cites the mineral system depend- 

 ent on the elements lime, alumina, and silica, which elements 

 include in their multifarious possible combinations the well- 

 known but hitherto little understood compound called portland 

 cement, whose properties have been determined as an incident 

 to the general problem presented by this system. 



Among the numerous problems under investigation at the 

 Laboratory, one of immediate economic as well as of great theo- 

 retical interest may be cited here by reason especially of the fact 

 that funds for its execution have been supplied by industrial 

 sources; this is the problem of the ^'secondary enrichment of 

 copper ores," and the success attained in its treatment demon- 

 strates the practicability of advantageous cooperation between 

 the Laboratory and industrial organizations without restriction 

 to scientific procedure and publicit3^ The section of the Direc- 

 tor's report devoted to this subject should be of special interest 

 to geologists and to mining engineers as well as to copper-mining 

 industries. A more comprehensive idea of the productive activi- 

 ties of the Laboratory may be gained by a glance at the section 

 of the Director's report in which he gives brief abstracts of the 

 publications which have emanated from members of the staff 

 during the year. These publications embrace fortj^-nine titles 

 of papers which have appeared in current journals or are in 

 press, many of them having been published in German as well 

 as in English. 



The investigations of the Department of Historical Research 



have proceeded effectively in accordance with the plans outlined 



D artment of ^^ ^^^ Dircctor in his reports published in previous 



Historical Year Books. In addition to the members of the 



permanent staff, several collaborators have taken 



part in these investigations, which have required explorations of 



historical archives in England, Scotland, France, Spain, Holland, 



