28-26 NP PREFACE TO THE SECOND EDITION. THE first edition of Select Methods in Chemical Analysis is exhausted, and the multitude of new methods which have been introduced into laboratory practice renders it necessary that the work should be not merely revised, but to a great extent rewritten. In submitting the new edition to the chemical world there are a few points to which attention must be called. It has not been desired to produce an encyclopædia of chemical analysis, in which is laid down every good method for the qualitative and quantitative examination of every known substance under every possible combination of circumstances. Many processes and operations have been omitted as universally known, and many others as being untrustworthy, or at least doubtful. The Author has merely given such methods as have been proved in his own laboratory. Others— possibly no less efficient-have been passed over because he cannot vouch personally for their value. A main object has been to bring into notice a number of little-known expedients and precautions which prevent mistakes, insure accuracy, and economise time. The arrangement of the book has been adopted, not without careful consideration, as the one which necessitated the smallest number of back references. LONDON: Nov. 1885. 299706 |