Preface to Vol. Second of the American Edition.

The appearance of the second volume of this work at a considerable period after the publication of the first, would seem to require some explanation other than has been given by the English editors.

As will be perceived from the Preface to the first volume, the author had undertaken a revision of the work so far as it had been printed in England, with especial reference to the American edition.

This was performed with respect to three-fourths of the entire Treatise which had been issued, which therefore may be regarded as a fourth edition by him. The remainder has been printed simultaneously with the English edition, the sheets as they were produced being transmitted to the American publishers. A portion of the latter part had undergone the revision of the author himself, but, in consequence of his lamented decease, the residue has been issued under the auspices of the distinguished editors whose preface is appended. The present edition is therefore presented as the last revised work of Dr. Pereira, and the most complete that he published.

With reference to the additions made by the American editor to this second volume, it may be stated that they pertain to the prominent vegetable productions of this country, and to the directions of the United States Pharmacopoeia, in connection with all the articles contained in the volume which are referred to by it. Throughout the two volumes now completed, the last revision of the U. S. Pharmacopoeia has been referred to, and its directions followed.

The illustrations have been materially increased over former editions, and where an opportunity presented of inserting in the American edition more finished representations of plants, it has been done from the abundant resources of the publishers. The additions of the American editors are simply inclosed in brackets [ ], while those of the English have ED. appended to them. (And I've put all the footnotes into [gray brackets]. -Henriette.)

December 1, 1853.

The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1854.