This volume is published in succession to one upon the Vegetable Kingdom, and is arranged upon a similar plan. Several of our best modern treatises upon the same subjects completely separate pharmacology from therapeutics, but it has seemed to me better to recommend their simultaneous study, and I have devoted more space than is now usual to pharmaceutical chemistry; this will be to the advantage, I am sure, of the student, and I trust, of the practitioner. That ample space should be given to discussing the physiological action of medicines is a necessary condition of any modern work, and if the conclusions reached, and the bearings of facts gathered under this head, are still rather vague and undefined, they at least engage and deserve earnest attention, and point to the direction in which further advance may be made.

My former volume was published in 1874, and as some explanation of the long interval between it and the present one, I may say that in 1877 I had commenced arrangements with the printer when a serious railway accident interrupted my work, and incapacitated me for any exertion for upward of two years; the conditions under which I have now completed the book may perhaps be accepted as some apology for its defects.

During the interval, several excellent treatises on the same subjects have been published, and I have to acknowledge many obligations to those of Dr. H. C. Wood, Jr., Dr. Bartholow, Dr. Garrod, Dr. Ringer, as well as to the works of Trousseau, Stille, Husemann, Nothnagel, Kohler, Gubler, and Rabuteau. I am also indebted to the "Poisons" of Dr. Taylor, the "Therapeutics" of Dr. Waring, the "Commentary" of Dr. W. G. Smith, the "Handbook" of Dr. Fothergill, the "Companion" of Squire, and the "Chemistry" of Miller: the latter I have mainly followed as to mercury, iron, and other important drugs, but it is possible that some discrepancies may still be found between older and more modern chemical formulae.

The "Medical Digest" of Dr. Neale I have found exceedingly useful. Various important monographs, e.g., those of Preyer, Binz, Liebreich, Frazer, Brunton, and others, and valuable papers in various journals will be found quoted in their proper place.

The abbreviations and references will, I believe, be found sufficiently full for easy recognition. The British and Foreign Medico-Chi/rurgical Review is quoted either as Brit. and For. Rev. or as Med.-Chir. Rev.; the Edinburgh Journal of Medicine as Edin. Journ.; the American Journal of the Medical Sciences as Amer. Journ. or Amer. Rev.; Practitioner refers to the London journal of that name, unless otherwise specified; Dub. Quart. or Dub. Journ. to the Dublin Journal of Medical Science.

Finally, I have to thank Dr. Mackey, Dr. Menzies of Cannes, Dr. Port, and Mr. A. Pearce Gould, for their valuable assistance in looking up references and aiding me with many suggestions and corrections while the work was passing through the press.

2 Grosvenor Square, London, W., December 1, 1881.