AUTHOB'S PEEFAOE
TO
THE ENGLISH EDITION
��Originally published in French, 1 this small book had the good fortune to attract the attention of the late Dr. F. Hurter, who in April 1897 secured the right of translation. This distinguished chemist, owing to the pressure of technical work, had only translated the first two parts of brought his labours to a close and robbed me of my friend and collaborator.
The work thus interrupted was later taken up by Dr. J. McCrae, but as in the interval I had recognised the necessity of modifying many passages in the book and even of entirely rewriting many chapters (particularly in the first half) my new collaborator could make little use of the translation prepared by Dr. Hurter and found himself confronted with a totally new task.
The work now proceeded more rapidly than before, and during the University vacation the revision of the original
1 By H. Lamertin, Brussels, 1897.
�� �
