INDEX TO THE LITERATURE OF DIDYMIUM — 



1842-1893. 



By a. C. LANGMUIR, Ph. D. 



The following paper is offered to chemists with the hope that it may 

 be of some value to them in their researches on an element of great 

 theoretical and scientific interest, particularly as an example of the 

 wonderful results accomplished by the use of the spectroscope in mod- 

 ern chemistry. The voluminous literature of didymium affords a 

 striking illustration of the pursuit of science for its own sake, and with 

 no reward beyond the satisfaction of having advanced the cause of 

 truth. 



Original work, at the present time, must always be preceded by a 

 long and painstaking search through the literature, which consumes no 

 inconsiderable amount of time. Anything which can lighten the labors 

 of the investigator in this direction is sure to be a welcome addition to 

 the literature. 



In 1882 Dr. H. Carrington Bolton originated the idea of indexing 

 the literature of each of the chemical elements, and a Committee on 

 Indexing Chemical Literature was appointed by the American Asso- 

 ciation for the Advancement of Science. The committee annually 

 reports the progress made during the year, the reports being published 

 in the Chemical News and in American journals. 



The following elements have been indexed : — 



Columhium. — Index to the literature of, 1801-1887, by Frank W. 

 Traphagen, Smithsonian Miscellaneous Collections, No. 663, 

 , Washington, 1888. 



