PREFACE. THE chief object in prepsr. ing the present English edition of this book has been to include a consiclerable nunlber of new electronnalytical methods which have been published since thc appearance of the fourth Germnrl edition in 1397. This task has been greatly simplified by the very kind assistance of Professor Classen, who has generously placed his new and valuable work on Ausgex-Bhlte Vethoden der Analytischen Chemnic, published in Berlin in 1902, at the disposal of the translator. This book covers 3 wide field in flnalyticrtl chemistry and embraces n vnrictj-of special subjects. Tt has beer1 freely usecl in preparing thc present English edition. Part First of the Gennnn original has been divided into tn-o sections, and the arrangement of the text has been alter d to permit of a more systematic treatment of the subject. JIuch new mater ial has beer introduced into this part, and acknowledgment is especi lly due to Professors Hastings ancl Beadl, from vhoscT ext-Book af General Physics rnnnp of the descriptions of electrical apparatus have been taken. To Part Seconci many new methods of analysis haw been atlded, thc source of these being Professor Classens book mentioned above and the original papers in the chemical journals. The translator has attempted to retain all of the valuaIjle material contsincd in the fourth German edition and is solcly responsible for any errors or mistakes in the new material which has been inserted. He desires to express llere his tbanlrs to Professor H. A. Burnstead of the Sheffield Scientific School for his valuable advice and criticism. B. B, BOLTWOOD. NEW HAVEN C , onn., April, 1903. CONTENTS . PART FIRST . CEAPrER I . I1 . 111. IV . V . V1 . VJI . VIII . I S . Y ...