vi PREFACE. 



are frequently introduced, and it is hoped that this grouping will outweigh 

 the advantages of arrangement in a single alphabet. 



Owing to circumstances, partly unavoidable and partly intentional, the 

 seven Sections are unequally developed : 



I. The Section of Bibliography is believed to be quite full and in- 

 cludes to some extent special bibliographies occurring in periodicals ; but 

 bibliographies of individuals are placed in Section IV., Biography, under 

 the name of the chemist. 



II. The Section of Dictionaries is thought to be tolerably full ; in 

 this connection are placed Tables giving a conspectus of chemical bodies 

 (not, however. Tables for Analysis), and works on Nomenclature. 



III. The Section of History is more nearly complete, having been 

 in course of preparation for several years. It is in fact a second edition 

 of my " Outlines of a Bibliography of the History of Chemistry," pub- 

 lished in 1873. (Ann. N. Y. Lye. Nat. Hist., Vol. x.. New York, 1873.) 

 In this division also periodical literature has to some extent been explored. 



IV. The Section of Biography is less complete, yet pains have been 

 taken to index the necrologies in several periodicals. The chief of these 

 periodicals are Ber. d. chem. Ges.; Am. J. Sci.; Nature ; Ann. Chem., Crell ; 

 Allg J. Chem., Scherer and Gehlen ; Chem. News ; Bull. Soc chim., 

 Paris ; Pop. Sci. Mon., New York ; J. Chem. Soc, London. In this 

 Section special bibliographies of individuals are placed under their names. 



V. While Section V., Chemistry pure and applied, is more extensive 

 than the other six combined, it is the least satisfactory to the editor. Besides 

 pure chemistry it comprises works in every department of chemistry applied 

 to the arts, but not works on the arts themselves ; thus agricultural chem- 

 istry is given place, but not agriculture : pharmaceutical chemistry, physi- 

 ological chemistry, etc., find place, but not the sciences of pharmacy and 

 medicine. It is of course often impossible to draw the line sharply and 

 in doubtful cases the tendency has been to include rather than exclude ; 

 hence many works on technology are included especially when chemistry 

 lies at their foundation. It is probable, however, that this has not been 

 done uniformly, owing to the difficulty of selection. 



Readers should not expect to find in this Section complete lists of the 

 works of a given author ; though some pains have been taken in the case of' 

 prominent men to catalogue their writings fully. (See under Berzelius, 



