29 OCTOBER 1887, Page 23

Practical Organic Chemistry. By J. B. Cohen. (Macmillan and Co.)—A

laboratory guide to the preparation of the more important fatty and aromatic bodies is much needed. The student is apt to get both his ideas and his methods somewhat hazy as to these com- pounds, corning to them from the easier and perhaps cleaner methods of inorganic chemistry. Dr. Cohen gives, before each preparation, the literature bearing upon the subject, and supplies a short method, with a woodcut, of any apparatus at all out of the way. A few lines are devoted to the equation and the properties. An appendix contains notes on each experiment, and also some useful tables of per-centages. An index completes the volume. The student should find this guide very useful; and if he is not able to reproduce the cuts of apparatus, they will at least give him an idea of the material needed, besides conducing to that so mach needed quality, neatness of work, one which cannot be too carefully cultivated. The reversing of the canal order of fatty and aromatic bodies, besides altering their relative chemical and historical importance, is somewhat doubtful policy. While in the inorganic department there has been an over-production, there has been a great want for a similar guide in organic chemistry. This we think Dr. Cohen has to a great extent supplied in a volume which, being small, neat, and handy, makes laboratory students independent, and obviates the necessity of constant reference to some gigantic and unwieldy volume only meant for the study.