PREFATORY NOTE 



The present book commemorates the one-hundredth anniversary 

 of the founding of the American Journal of Science by Benjamin 

 Silliman in July, 1818. The opening chapter gives a somewhat 

 detailed account of the early days of the Journal, with a sketch 

 of its subsequent history. The remaining chapters are devoted 

 to the principal branches of science which have been prominent 

 in the pages of the Journal. They have been written with a 

 view to showing in each case the position of the science in 1818 

 and the general progress made during the century; special 

 prominence is given to American science and particularly to the 

 contributions to it to be found in the Journal's pages. Kefer- 

 ences to specific papers in the Journal are in most cases included 

 in the text and give simply volume, page, and date, as (24, 105, 

 1833) ; when these and other references are in considerable 

 number they have been brought together as a Bibliography at 

 the end of the chapter. 



The entire cost of the present book is defrayed from the 

 income of the Mrs. Hepsa Ely Silliman Memorial Fund, estab- 

 lished under the will of Augustus Ely Silliman, a nephew of 

 Benjamin Silliman, who died in 1884. Certain of the chapters 

 here printed have been made the basis of a series of seven Silli- 

 man Lectures in accordance with the terms of that gift. The 

 selection of these lectures has been determined by the conveni- 

 ence of the gentlemen concerned and in part also by the nature 

 of the subject. 



