Some apology is required for the long delay in the appearance of this work, for a number of years have now elapsed since it was advertised as being in the press. More than fifteen years ago, I had a work on Materia Medica completely written out and ready for the printer. Some time afterwards, all the arrangements had been made for its publication, and in the course of a few weeks it was to have been issued from the press. Just as I was about to send it to the printer, however, I asked for a little delay in order that I might make some improvements and remove some redundancies, for the work as it then stood was considerably larger than the present one.

As I went through it, I found so many unsatisfactory statements and uncertainties regarding the mode of action of drugs, which I thought I could decide by a few experiments, that I wished for a little time in order that those doubtful points might be settled; but as I went on the labour grew, other engagements became pressing, and longer and longer delay was required. From greater experience as a teacher and examiner also, I came to the conclusion that the plan of the work might be altered with advantage; and so finally the whole manuscript was thrown aside, and the book entirely re-written.

In the original work I discussed the physiological and therapeutical actions of each drug separately, in the same way as in the third part of the present work, though on a much more extended scale. I found, however, that this plan necessitated a good deal of repetition regarding the experimental methods by which the action of the drugs had been ascertained.

Moreover, the physician does not want to know only what the actions of any one drug are; he rather requires a knowledge of classes of drugs, and of the manner in which the actions of the individual members of a class differ from each other. He requires, in fact, a knowledge of the ways in which the various functions of the body can be influenced by drugs both in health and disease, in order that he may restore health to his patients.

It has appeared to me, therefore, better to devote a complete section of the work to a discussion of the methods by which the action of drugs is determined; to the manner in which each function of the body can be modified by drugs; and to the general rationale of the use of drugs in disease, i.e. to devote a section to general pharmacology and general therapeutics.

Considerable experience both in teaching and examining has shown me that students sometimes find a difficulty in applying physiology to pharmacology and therapeutics, and I find that many others are, like myself, apt to forget those parts of physiology which they are not constantly studying. I have therefore thought it well, for the sake both of students and practitioners, to give a short account of the normal functions of the different parts of the body, before proceeding to discuss the alterations which are produced in them by drugs, or which they undergo in disease. In the case of the heart and the kidneys also, where the action of drugs is complicated and difficult, I have found it necessary to enter a little more fully into the physiology of these organs than is done in the ordinary text-books.

I have found that a similar difficulty occurs with pathology as with physiology, and I have therefore occasionally discussed pathological questions when I have thought that by doing so I could render the action of drugs in disease more intelligible, and thus aid the student of rational therapeutics.

In the second part of the work on general pharmacy, I have classed together the various pharmaceutical preparations, and given lists of them for reference. It is by no means my intention that these should be learned by heart by any student, and indeed I think it is well to take this opportunity of protesting against the injustice of the demands which are sometimes made upon the memories of students.

It is probable that the majority of the best and most successful practitioners would be very much puzzled if they were required to state the exact quantity of every ingredient in each pill or each ointment that they prescribe, or the exact quantity of the crude drug from which the infusions or tinctures which they use have been made. They know the action of the pill or ointment, they know the action of the infusion or tincture, and they do not trouble themselves about details which are only useful to the chemist who is making up the preparation.

It is very greatly to be regretted, for it is a stumbling-block in the way of true progress, that students who have afterwards to become medical practitioners and not pharmaceutical chemists, should be asked at examinations the quantities of crude drugs from which particular preparations are made - quantities which even the manufacturing chemist himself would never dream of carrying in his memory, but would obtain by reference to his books whenever he required them. As the late Professor Sharpey used very truly to say, ' You may as well require of a medical student a knowledge of the whole art of cutlery before you set him to dissect.' Medical science is now advancing in every direction, and unless we cut off some of the less useful kinds of information, which medical students were formerly obliged to acquire, it becomes impossible for them to learn all that is truly valuable. In

Materia Medica we now oblige them to learn the physiological action of drugs, a subject regarding which, until quite recently, little or nothing was known, and to oblige them to learn all this, in addition to what they were formerly expected to know, is to treat them as Pharaoh treated the Israelites, and compel them to make the same number of bricks, while giving them no straw.

I am so much impressed with the necessity of lessening the amount of unnecessary work sometimes required as a preparation for examinations, that at first I omitted from this book all reference to the composition of pharmaceutical preparations. But as it is intended not only as a text-book for students, but also for the use of practitioners, I afterwards considered that it might be convenient to have the composition of some pharmaceutical preparations, at least, for the purpose of reference. I have omitted the composition of such preparations as are like to be got ready-made from a chemist, but have inserted the composition of infusions which often need to be prepared when required. I have also given the composition of various compound pills, but only for the purpose of reference.

In consequence of this change in the plan of the work while it was passing through the press, the preparations of rhubarb have been omitted from their proper place at page 924, and are to be found at page 1005.

In the preparation of this work I have to acknowledge my obligations to the admirable works of Bartholow, Binz, Buchheim, Dujardin Beaumetz, Edes, Husemann, Nothnagel and Rossbach, Ringer, Schmiedeberg, and H. C. Wood. Messrs. Chapman, Soutter, Spencer, Spry,1 Steinthal, Stubbs, Walsh,1 Wells, and Wright for the excellent notes they took of my lectures; to Dr. D'Arcy Power for the verification of references; to Dr. Mitchell Bruce, Mr. T. W. Shore, and Mr. H. W. Gardner for much kind assistance in the preparation of the work, and to Prof. Matthew Hay, of Aberdeen, whose criticisms and suggestions have been invaluable. To Dr. Francis H. Williams, of Boston, Mass., I am indebted for the adaptation of this work to the United States Pharmacopoeia, which by tending to familiarise medical men on each side of the Atlantic with the preparations employed in both countries may, I trust, tend to facilitate the introduction of an International Pharmacopoeia.

T. Lauder Brunton

March, 1885.

1 These names were inadvertently omitted in the preface to the first edition, but were mentioned in the preface to the second.