916 INDEX TO THE LITERATURE OF URANIUM, 1789-1885. 



Each of these schemes is open to objections and fraught with diflicul 

 ties that need not be named. On the whole, the third plan seemed to a 

 majority of the committee the only feasible one for the present. The 

 report also considers the best arrangement of material, and three ways 

 are suggested: (1) chronologically; (2) alphabetically by authors ; (3) 

 topically. The committee do not venture to dictate to volunteer and 

 independent workers, but recommend the chronological arrangement, 

 accompanied by a topical index. 



In September, 1884, the committee further reported that several 

 indexes had been published during the twelve months intervening, and 

 that more were in progress. They also announced that the Smithsonian 

 institution had consented to j)ublish indexes to chemical literature 

 indorsed by the committee, limiting somewhat the number of pages 

 per annum. The Smithsonian Institution also distributes, free of 

 exi)ense, the circulars and publications of the committee. 



The following work is offered as an additional contribution to the series 

 of indexes named below. It is, strictly speaking, a second edition of 

 that published in 1870, but much new matter has been added and new 

 features introduced, so that in reality it forms an entirely new work. 

 The edition of 1S70 contains 522 references to papers by 150 authors ; 

 the present index contains 1,330 references to papers by more than 300 

 authorities. New matter has been incorporated with that of the first 

 edition, and the whole has been brought down to the close of 1885, cov- 

 ering ;i i)eriod of sixteen years of much activity. In each paragraph 

 the first reference following the name of an author is that of the original 

 publication of the paper in question; the succeeding references are those 

 of reprints or abstracts of the original. 



In accordance with the suggestion of the index committee, two indexes 

 have been added — an alphabetical index of authors and a classified in 

 dex of subjects. These, it is believed, will materially increase the utility 

 of the work. The scheme of classification adopted for the subject index 

 is by no means an ideal one. It is not intended to serve as a model for 

 others, but it is deemed the most satisfactory attainable with the material 

 in hand. Knowing, moreover, that as a rule classification schemes are 

 intelligible only to their authors, we have added a synopsis of the clas- 

 sification to serve as a key. In using the author and subject indexes, 

 it must be I'emembered that they refer to the items in the chronological 

 index, and that the contents of each paper are not comiDletely indexed. 

 Finally, the list of abbreviations will remove doubts as to the journals 

 quoted, and will show at the same time what sets have been thoroughly 

 examined. 



H. CARRINGTON BOLTON, 

 Chairman of Committee on Indexing Chemical Literature. 



