Chemistry 621 



time and apparatus of its chemist, or which for other reasons 

 could not be undertaken by him. 



With the resignation of Mr. Taylor the place of official 

 chemist to the Institution ceased to exist. An arraneement 

 was then made between the Secretary of the Institution and 

 the Director of the United States Geological Survey, by 

 means of which the laboratory in the Institution was placed 

 in charge of Professor Clarke, chief chemist of the Survey, 

 with the understanding that Professor Clarke should perform 

 such chemical work as might be called for by the Institution. 

 This procedure was in accordance with the policy of relin- 

 quishing such lines of work as could be satisfactorily carried 

 on by other departments of the government, and of fostering 

 only such branches of investigation as were not provided for 

 elsewhere. For nine years nearly all of the chemical work of 

 the Survey was done in the rooms assigned to that work in 

 the Museum building, but in 1892 the analytical work was 

 transferred to the new offices of the Survey. In addition to 

 the foregoing, considerable chemical work pertaining to me- 

 tallurgy and economic geology was performed during these 

 years in the departments of metallurgy and economic geology 

 and of lithology and physical geology by their respective 

 curators, Frederic P. Dewey and George P. Merrill. Since 

 1892 such chemical work as has been required by the Insti- 

 tution has been conducted in the laboratory now in the De- 

 partment of Geology under the direction of the curator, 

 Doctor George P. Merrill. 



Soon after the publication of the three parts of the " Con- 

 stants of Nature," Professor Clarke began collecting data 

 relative to the determinations of atomic weights for the pur- 

 pose of preparing a complete digest of the entire subject, and 

 of recalculatinor all the estimations. Much material had been 

 collected and partly discussed when a manuscript entitled 

 40* 



