It was with the greatest reluctance that the authors of the first edition undertook in 1908 the preparation of another medical text-book. They found however that none of the books on Pharmacy and Materia Medica were at all suitable for use in their classes in the University of Toronto. Most of the books on these subjects contain also sections dealing with Pharmacology and Therapeutics. These sections are rarely accurate. Changes in the official Pharmacopoeia occur much more slowly than does our knowledge of Pharmacology. Several of the better books on Pharmacy and Materia Medica are intended for students in the United States and deal largely with the U.S. Pharmacopoeia. As there are several good books on Pharmacology on the market which undergo frequent revision, the authors did not include any material relating to this subject.

The classification of drugs according to their botanical, mineral or animal origin is no longer of importance, nor does a pharmacological classification furnish an arrangement useful for reference purposes. A use of one of these types of classification greatly mars some otherwise useful books.

These considerations forced the authors to compile this text-book and they hope that they have succeeded in placing before the student a book which will aid him in writing prescriptions.

Dr. C. P. Lusk then Lecturer in Pharmacy was associated with the author in the preparation of the first edition and in spite of the fact that the book has been almost completely rewritten many traces of his practical knowledge and scholarship are to be found in the present edition. The stress of work which necessitated his retirement from the Department has led to his not taking the same part in the preparation of the second edition, that he did in the first. The author wishes to thank him for his great kindness in reading the copy of this edition and for his valuable criticisms and suggestions and regrets that Dr. Lusk felt constrained to withdraw his name from the title page.

The following works have been frequently consulted:-The British Pharmacopoeia; The British Pharmaceutical Codex; Squire's Companion to the British Pharmacopoeia; Ruddiman, Incompatibilities in Prescriptions; Elborne, The Elements of Practical Pharmacy and Dispensing; The Art of Dispensing, (published by the Chemist and Druggist); Fantus, Prescription Writing and Pharmacy; Bennett, Medical and Pharmaceutical Latin; The United States Pharmacopoeia.

University of Toronto, V. E. Henderson.

October 23, 1911.