198 527 1918 PREFACE THE new editions of the United States Pharmacopoeia and the National Formulary and the advances in pharmacy have made a revision of the Essentials necessary. The present volume has been greatly enlarged and entirely rewritten. Experience has shown that a compend in the form of questions and answers rather imperfectly met the form of instruction that the author desired to impart. Compends of this character are apt to be misleading their value is likely to be overestimated by the student. A rearrangement of the work was, therefore, deemed advisable, but administrative work in recent years has deprived the author of the former Essentials of the necessary time to accomplish this. The present volume has been made possible largely through the acceptance of joint authorship by Professor L. D. Havenhill. The object of the book is not to furnish an exhaustive treatise, but rather to give a simple brief outline of the important pharmaceutic data in convenient arrangement, and to inspire the student to make free use of the U. S. P., N. F., and other works of reference. The vegetable materia medica has not been touched upon. mainly because it would increase the size of the volume beyond the desire of the authors, and because it constitutes a separate subject of sufficient size and importance to be treated independently. The division of the Essentials into six chapters, each having an alphabetic arrangement, is designed to make reference easy. For the benefit of those who are unfamiliar with this arrangement and for use in locating those subjects that do not conform to it, an index is provided, but in order to use the volume most profitably-to obtain the help which the work is desired to give the student-he must learn to use the volume itself. This, it is hoped, will require only a small amount of effort. UNIVERSITY OF KANSAS, LAWRENCE, KANSAS. THE AUTHORS. 11 General Methods for Preparing Salts (Synopsis). List of Medicinally Important Elements and Their Representative U. S. P. and N. F. Compounds... List of U. S. P. and N. F. Salts Classified According to Acid |