PREFACE. 



THE methods brought together in the present volume 

 are, of course, chiefly taken from the literature scattered 

 through various original papers and text-books. But the 

 author has always endeavored, so far as possible, to reach 

 an opinion from his own experience concerning the methods 

 described ; and many of the details and modifications of 

 previous methods contained in the book are due to his own 

 investigations. 



However, the literature used has been as fully quoted as 

 possible at all points, in so far as it seems of present value. 

 Works of merely historical interest are not referred to, since 

 the book is designed only for practical use. 



If the writer has overlooked many statements of value, it 

 is to be hoped that it will be understood and pardoned by 

 those familiar with the immense extent of botanical litera- 

 ture, especially in recent years. The author will be grateful 

 to any one who will call his attention to such omissions. 



Regarding the quotation of literature, it may be said that 

 numerals are placed after authors' names in the text, which 

 refer to the literature list at p. v, the first (Roman) num- 

 ber indicating the work, and the second, the page of the 

 work cited. Where the author was not able to consult the 

 original in the preparation of this book, the abstracts used 

 are referred to. 



In the arrangement of the organic compounds, Beilstein's 



