AUTHOR'S PREFACE.

THE author wishes it to be clearly understood that the book is only intended for the use of students who are undergoing or have undergone a substantial course of instruction in the principles of organic chemistry. Its primary purpose is that of a laboratory guide, and its use should be supplemented by reference to some of the large text-books, as well as to the original sources of chemical literature mentioned at the head of each preparation. For convenience of immediate reference, and in the hope of emphasising some of the important facts, an Appendix is added, containing some notes explanatory of the theoretical importance of the reactions involved in the preparations.

The preparations have been selected and arranged with the object of illustrating the relationship existing between certain groups of organic bodies, as well as their characteristic reactions.

The usual arrangement of fatty before aromatic compounds has been reversed for the reason that those of the latter, which have been selected, offer fewer difficulties to the beginner.

For valuable assistance given him by Professor Schorlemmer and Professor Smithells, to Professor Emil Fischer, to whom he is indebted for the details of some of the preparations, to Dr. W. H. Perkin, junior, and others, the author's best thanks are due.

TO THE STUDENT.

Before beginning the preparation, read the recent literature on the subject, reference to which will be found at the head of the preparation, and refer to it in your text-book. A few explanatory notes are added in the Appendix. Weigh the quantities prescribed on a rough chemical balance. Note the yield

of the product in each case, and compare it with the quantity theoretically obtainable.

OWENS COLLEGE, April, 1887.