CLASSIFICATION OF MEDICINES.

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hedron). The fundamental form is either the right rectangular or the right rhombicprism. The following are the pharmacological agents belonging to this group :—

Bichloruret MercurySesquisulphide AntimonySesquisulphide Arsenicum(Orpiment)

Carbonate LeadCarbonate BarytaSulphate Potash

Sulphate MagnesiaSulphate ZincNitrate SilverNitrate PotashCitric Acid Bitartrate PotashSoda-Tartrate Potash

MorphiaSulphur (native)

Emetic TartarWhite Antimony (pro-toxide)

Group 4th. Oblique Rectangular or Oblique Rhombic Prismatic System.—(Oblique Prismatic System).— The primary forms included in this system are, the ObliqueRectangular Prism, the Oblique Octahedron with a rectangular base (Oblique RectangularOctahedron), the Oblique Rhombic Prism, and the Oblique Octahedron with a rhombic base(Oblique Rhombic Octahedron ). Mr. Brooke (Encyclopcedia Metropolitans art. Crystal-lography) refers the Right Oblique-angled Prism to this group. The fundamental formof this system is the Oblique Prism (either rectangular or rhombic). The followingpharmacological agents belong to this group :—

Sulphur (by slow cooling) Sulphate Iron Acetate Copper

SulphideArsenicum (Real- Chlorate Potash Acetate Zinc

g-ar) Phosphate Soda Tartaric Acid

Carbonate Soda Borax Oxalic Acid

Sulphate Soda Acetate Soda Sugar.

Group 5th. Doubly Oblique Prismatic System. —This system includes the DoublyOblique Prism (also called the Oblique Prism with an oblique-angled parallelogram for itsbase.) The following pharmacological agents belong to this system:—

Sulphate Copper Sulphate Citichonia Nitrate Bismuth

Group 6th. Rhombohedric System (Mohs).—The primary forms of this group are,the Rhombohedron (also termed Rhomboid), the Bipyramidal Dodecahedron, and theRegular Hexagonal Prism. The fundamental form is the Rhombohedron. The follow-ing pharmacological agents belong to this group:—

Antimony Carbonate Zinc Nitrate Soda

Plumbago Bisulpburet Mercury Hydrate Magnesia

Carbonate Litne Ice Chloruret Calcium

Carbonate Iron

c. Classifications founded on the Chemical Constituents. —The difficul-ties attending the analysis of organized substances form a great obstacleto the formation of a chemical classification. Most of the writers whohave attempted an arrangement of this kind are German.

Donald Munro, A Treatise on Medical and Pharmaceutical Chymistry, and the Ma-teria Medica. London , 1788.

C. H. Pfaff, System der Materia Medica nach chemischen Principien mit Riicksichtauf. d. sinnl. Merkmale und d. Deilverhaltnisse der Arzneimittel. Leipzig , 7 Bde,1808-24.

F. A. C. Gren: Handbuch der Pharmacologie, 3te Aufl. herausgegeben von Bern-hardt und Buchholz, 2 Bde. Halle u. Berlin, 1813.

F. G. Voigtels, vollstand. System der Arzneymittellehre, herausgeg. von Kuhn. 4 Bde.Leipzig , 1816-17.

C W. Hu/eland, Conspectus Materi* Medicte, Berolini, 1816, ed. 2, 1820; ed. 3,1828.

G. W Schwartze, Pharmacologische Tabellen, oder system. Arzneimittellehre intabell. Form. Leipzig , 1819-25. 2 Aufl. fol. 1833.

G. A. Richter, ausfuhrliche Arzneimittellehre, Handbuch fur prakt. Aerzte. 5 Bde.u. 1. Suppl. 1826-32.

As an example of a chemical classification I shall select Schwartze’s,and must refer the reader to the late Dr. Duncan’s (jun.) Edinburgh Dis-pensatory , 11th ed. p. 172, for Pfafl’s chemical classification of thevegetable materia medica.