The Author of the present volume has for some years devoted time and attention to a special study of the therapeutic action of drugs, and had hoped ere this to place the results of his labour before the Profession. In the progress of his task, however, he has discovered that every new fact obtained, suggested a new subject for investigation and research, while the experience gained by clinical observation did not tend to diminish the difficulties which seemed to him to surround so exhaustless an inquiry. He was, moreover, unwilling to content himself with a compilation of the data collected by others, or with that apparent simplification of the subject so common in works on Therapeutics, but which too often results only from a hasty credence in statements consonant with the writer's ideas, and a neglect of others not in harmony with those preconceived conclusions.

It was the intention of the Author to have appended to the present volume a more detailed account of his experience of the treatment of disease derived from clinical study, but the publication of the British Pharmacopoeia rendered it desirable that a text-book should be immediately in the hands of the Student and Practitioner of Medicine, and hence the second edition of the "Essentials of Materia Mcdica and Therapeutics" is now published alone. The Author still hopes, in the course of a few months, to bring before the Profession a separate volume devoted exclusively to the value of medicines in the treatment of disease, and embracing the whole subject of Therapeutics.

The present work is intended to serve as a text-book of Materia Medica, and while it is hoped that it omits nothing essential to the study of the science, it excludes such details as are often embarrassing to the Student and seldom necessary to the Practitioner. It has been his object, while limiting its size, to include all points connected with the officinal preparation of medicines, and so much information on the therapeutic action of drugs as would serve as a sufficient guide in actual practice. All controversial points have been avoided, as unsuited to the design of the work; and the information confined to the facts really ascertained as to the action of each drug, and the purposes for which it has been advantageously employed.

A Table of Contents, by a glance at which the reader will at once see all drugs scientifically arranged, together with their pharmaceutical preparations, is contained in the present edition; as likewise a Table indicating the principal changes of nomenclature and important differences of strength between preparations in the British Pharmacopoeia and in the London Pharmacopoeia, 1851; and lastly, a somewhat copious Posological Table is now introduced.

Under some articles there will be found references to Appendix A. and Appendix B.; when such is the case it implies that the substance is contained in the Appendix of the British Pharmacopoeia.

The Author desires, in conclusion, to express his obligations to Dr. Footman for the assistance kindly rendered in the preparation of the present edition of the "Essentials of Materia Medica and Therapeutics."

84 Harley Street, Cavendish Square, W.,

May, 1864.