In preparing the ninth edition it has been found necessary to enlarge the work by forty-five pages. Additions and alterations have been made at all points to dispose of the new material which the rapid development of pharmacology has contributed to the science and art of therapeutics. Much of this matter consists of accounts, more or less full, of the synthetical remedies which organic chemistry has produced and is producing in increasing numbers. For the most part these medicaments are proprietary, and are not therefore to be found in the official list of the United States Pharmacopoeia. Receiving special designations often suggestive of their mode of action, they cease to be known by the technical nomenclature, and, under patent protection, are the property of the manufacturing chemist. When, by the substitution process, a remedy is evolved that seems likely to possess certain powers, it is placed in the hands of some friendly investigator to study its physiological actions, and it is then duly exploited by the manufacturer. It is undeniable that many important contributions have been thus made to practical medicine; but it is equally true that many have not sustained the pretensions of their promoters, and have either failed entirely of recognition or have only in part justified the extravagant claims made for them. The whole subject is yet hardly in a state to select out of the mass those that time and further clinical experience must justify. As in nearly every instance these remedies are derived from the aliphatic (fatty) and aromatic series of organic compounds, it is not surprising that there should be in respect to many of them considerable similarity in the mode and character of their actions. In the absence of an authoritative tribunal to decide on the remedies for recognition and use, I have employed my own judgment in selecting those for treatment in this work. Time will determine the value of those taken up for consideration: some will continue in favor; the failures will be eliminated.

I must again give expression to the gratitude I feel over the long-continued success of the work; for the disappearance of successive large editions is the best evidence of appreciation by my readers and of approval by the organs of professional opinion.

Roberts Bartholow, M. D.

1527 Locust Street, Philadelphia, August, 1896.