IV PREFACE. 



in the Universitats- und Landes-Bibliothek, Strassburg ; Mr. Charles C. 

 Darwin, Librarian of the United States Geological Survey, Mr. David 

 Hutcheson, Superintendent of the reading-room, Library of Congress, 

 and Dr. Cyrus Adler, Librarian of the Smithsonian Institution ; the 

 practical sympathy with the work in hand shown by each of these 

 gentlemen made its accomplishment possible. 



During the printing of the volume I have had the assistance of Dr. 

 Oscar Loew in reading the proof of the German titles, of Dr. L 

 Casanowicz, who read the Russian, and of Prof, Jas. Lewis Howe, who 

 kindly read the proof of the subject-index ; to these gentlemen I here 

 express my sincere thanks. 



This, the third volume of The Select Bibliography of Chemistry, 

 completes the undertaking begun by the writer in 1888 ; the entire work 

 contains rather more than twenty-five thousand entries. The collection 

 of titles for a fourth volume is in progress and will afford an opportunity 

 of supplying omissions ; the deficiencies of the third volume are ad- 

 mitted and are realized in part by the compiler. 



Throughout the progress of this bibliography the writer has had the 

 cordial support of the Smithsonian Institution, and he desires to place on 

 record his appreciation of the substantial encouragement given him by the 

 Secretary, Mr. S. P. Langley, during the preparation of the manuscript 

 and the printing of the volumes. 



Henry Carrington Bolton. 

 Washington, D.C. 



