PREFACE vii 



where each page begins and ends. This is done for the con- 

 venience of commentators wishing to refer to the original 

 articles. All the papers have been reprinted essentially in the 

 form used by the author. The historical advantage of this 

 practice is obvious; and although usage in nomenclature, 

 notation, and spelling has somewhat changed during twenty- 

 five years, the older forms cannot in any of the present 

 instances give rise to misunderstanding. 



After the scientific contributions, Professor Loeb's labora- 

 tory manual of experiments for the elementary course in 

 inorganic chemistry at New York University is printed as an 

 appendix, together with the description of a brief series of ex- 

 periments upon the speed of reactions. These are included 

 not only for the sake of completeness, but also because they 

 may be suggestive to others confronted with the interesting 

 but difficult task of giving elementary instruction. 



A complete chronological list of all the separate essays is 

 given at the end of the volume, with the references to the 

 original sources; and an index of names completes the book. 



Other manuscripts and notebooks found in his laboratories 

 contained much that was almost ready for publication, but 

 probably nothing more that he himself would have con- 

 sidered as ready to appear in print. The preliminary search 

 among these papers was conducted at the request of his 

 family by Professor Charles Baskerville, of the College of the 

 City of New York, and Mr. D. D. Berolzheimer, a former 

 student of Professor Loeb's and the librarian of The Chemists' 

 Club; thanks are due to both for their valuable assistance in 

 making a preliminary selection and arrangement of the ma- 

 terial, and to the latter, as well as to Professor G. S. Forbes, 

 for their help in reading the proofs. To Professors Charles 

 Loring Jackson, Elmer P. Kohler and Gregory P. Baxter 

 also the editor is grateful for advice. T. W. R. 



