CLASSIFICATION OF MEDICINES. 57

W. P. C. Barton, M.D. Vegetable Materia Medica of the United States, 2 vols. 4to.Philadelphia , 1818.

J. Stephenson, M.D. and J. M. Churchill, Medical Botany, 4 vols. 8vo. London ,1827-31.

Flora Medica, 2 vols. 8vo. 1827.

The large number of substances employed in the treatment of diseasesrenders some arrangement of them almost absolutely necessary;—and Iconceive any order of treating of them to be better than none.

Arrangements or classifications of medicines, like those of plants, ( Thto -rie Elementaire de la Botanique, par P. Decandolle, 1819,) may bedivided into empirical and rational ones.

I. Empirical Arrangements. —These are independent of the natureof, and have no real relation or connexion with, the substances to bearranged. An alphabetical order, since it is founded on names whichare arbitrary, and have no relation to the bodies they are intended todesignate, is of this kind. Two advantages have been supposed to begained by its employment;—firstly, a ready reference to any particularsubstance ; and, secondly, the avoidance of errors committed by writerswho adopt other methods. But the first is more imaginary than real; foran index gives to any mode of classification every advantage derived froman alphabetical arrangement; and, as each substance is known by avariety of names, an index becomes as necessary to an alphabetical, as toany other method. Like other classifications this has its disadvantages,the most important of which are, that it brings together substances of themost incongruous natures, and separates those which agree in most of tlieirproperties; and from its want of order, it distracts the attention of thestudent, and is, therefore, totally unfitted for an elementary work.

The following arc some of the more important works in which medi-cines are described in an alphabetical order :■—

M. de la Beyrie, and M. Goulin, Dictionnaire raisonne-universel de Matiere Medicale,t. 8. Paris , 1773.

J. Butty, Mat. Medica antiquaet nova, repurgata et illustrata. 4to. Roterodam, 1775.

W. Lewis, an Experimental History of the Materia Medica, 4to. 1761.—4th edit, by

Dr. Aikin, 2 vols. 8vo. 1761.

Andrew Duncan, jun. M.D. The Edinburgh New Dispensatory, 11th ed. Edinburgh ,1826. Supplement to the above, 1829.

J. R. Coxe, M.D. The American Dispensatory. Philadelphia , 1806.

J. Thacher, M.D. The American New Dispensatory. Boston , 1810. 2d ed. 1813.

A. T. Thomson, M.D. The London Dispensatory. London , 1811. 9th ed. 1837.

J. A. Pam, M.D. Pharmacologia , 3rd ed. 1820. 8th edit. 1833.

W. Ainslie, M.D. Materia Indica. London , 1826.

W. T. Braude, A Manual of Pharmacy. London , 1825. 3rd ed. 1833.

A. Chevallier, A. Richard, and J. A. Guillemin, Dictionnaire des Drogues simples etcomposees; tom. 5, Paris , 1827-9.

F. P. Dulk, Die Preussische Pharmakopoe, iibersetzt und erlautert; 2 te Aufl. 2 Th.8vo. Leipsig, 1830.

L. Martinet, Manuel de Therapeutique et de Matiere Medicale. Paris , 1828.

F. S. Ratier, Traite elementaire de Matiere Medicale; tom. 2, Paris , 1829.

F. V. Merat et A. J. De Lens, Dictionnaire universel de Matiere Medicale et de The-rapeutique Generale, t. 6,1829-34.

L. IV. Sachs and F. P. Dulk, Handworterhuch der praktischen Arzneimittellehre,Konigsberg , 1830-37. 19 Lief. A.—St.

G. B. Wood, M.D. and F. Bache, M.D. The Dispensatory of the United States ofAmerica , 1833. 3rd edit. 1836.

Bachmann, W. L. Handworterhuch der praktischen Apothekerkunst, 2 Bde. Niirn-berg, 1837.

A. Ure, M.D. A Practical Compendium of the Materia Medica, with numerous For-mulae for the Treatment of Diseases of Infancy and Childhood. London , 1838.