merits in these respects. Your friends are incapable of disguising or withholding their sentiments, on the subject.

ATTACHED, as you are, to every branch of medical science; sensible, as you must be, of the imperfections of medicine, and ardently anxious for its further improvement, I will flatter myself, that you will peruse, with some satisfaction, these imperfect Collections, a mass of mere mishapen materials, out of which, at some future period, a part of a more regular AMERICAN MATERIA MEDICA may be constructed. Whether I shall live to take any part in the building, is extremely doubtful. The edifice is one, however, to which I look forward with an ardent zeal. A belief that I may possibly behold it, will serve to stimulate me to new and other labours, in this walk of medical science.

WITH the most sincere wishes for your health and happiness, and for the continuance of your useful labours and exertions, I remain,

Philadelphia, February 10th, 1804.

My dear Sir,

Your obedient and

Obliged friend,

BENJAMIN SMITH BARTON.

PREFACE.

I

EXPERIENCE some degree of pleasure in being able to fulfil one of my literary promises. I present to the public, a SECOND PART of my Collections for an Essay towards a Materia Medica of the United-States. I am not very anxious about the fate of the work, and therefore, I shall not offer any formal apology for its imperfections. These will be readily perceived by the reader of any experience.

IMPERFECT, however, as is this Second Part, I hope the student of medicine and the young practitioner, for whom principally it is intended, will find it not less interesting than the preceding part. It contains additions to many of the articles which are mentioned in the former portion of the work, besides facts and observations concerning other articles, which are either entirely unnoticed, or merely named, there. Some of the newly named articles have never before been noticed in any work relative to the Materia Medica: such are Myrica cerifera, Prinos verticillatus, Hydrastis Canadensis, Frasera Walteri, &c. How far these are worthy of the attention of physicians, must be left to others to determine.

To render the work somewhat more useful, I have interspersed it with occasional practical remarks. Some of these remarks, I am very ready to allow, are not necessarily introduced into the work. Such are those respecting Arsenic, and Digitalis. But it will be recollected, that I am not in pursuit of anything like a methodical or regularly-digested work: and if any value be attached to the remarks, I shall cheerfully submit to be censured for my want of order and arrangement, in the management of my subject.

THE principal, and indeed only, object which I had in view in composing the First Part of this little work, has been, in some measure, accomplished. I WISHED

TO TURN THE ATTENTION OF OUR PHYSICIANS TO AN INVESTIGATION OF THE PROPERTIES OF THEIR NATIVE

PRODUCTIONS. Already have I had the satisfaction to perceive the useful tendency of my labours. Several of the vegetables which I had mentioned in the Collections, have been examined with care and ability, by graduates in the University of Pennsylvania, who have thus put us in possession of a large body of useful information concerning those vegetables. It is unnecessary to mention, in this place, the titles of the dissertations to which I allude. Most of them are referred to in the present publication. Some of these dissertations reflect honour upon their authors; and must evince to the world, that an important branch of natural history and of medicine is making rapid advances among us. It is not one of the least pleasurable circumstances of my life, that I have been, in some degree, instrumental in directing the medical students of the United-States to a few of those objects, which have since solicited their attention.

IN the present portion of the Collections, I have called the attention of the student to other objects of the American vegetable kingdom, concerning which I am anxious to receive more extensive and more correct information. My various pursuits do not permit me to enter minutely into an investigation of the properties of the articles which I mention. Indeed, I wish it to be understood, that some of these articles have never been employed by myself in practice; and, consequently, that my information concerning them has been derived from the experience of other persons. It is obvious, therefore, that I cannot always vouch for the truth or accuracy of the observations, which I detail, concerning the properties and effects of our vegetables. But neither could I have vouched for their truth and accuracy, even though I had related them from my own experience. For where is the candid physician who will not confess, that he often errs? Where is the physician who will not acknowledge, that in the course of his practice, he has often ascribed effects to medicines, which those medicines did not produce? EXTRAORDINARY (PROVIDED THEY BE SOLITARY OR RARELY Observed) effeCTS OF MEDICINES, IN THE CURE OF DISEASES, SHOULD BE RECEIVED BY THE PHYSICIAN, WITH NEARLY THE SAME HESITATION WITH WHICH THE PHILOSOPHIC NATURALIST OR HISTORIAN, RECEIVES MIRACLES INTO HIS COLLECTION OF WELLASCERTAINED FACTS.