To Convert Grains into the Corresponding Metric Equivalents.It has been seen that I grain is equal to Gm. .065. In order, then, to convert grains or fractions of a grain into the corresponding metric quantity, we have simply to multiply the number of grains by .065. To Convert Metric Quantities into their Equivalent in Grains.— Instead of multiplying as above, divide, using the same number, .065, as a divisor. It follows that to convert Apothecaries' drachms into Grammes we multiply the number of drachms by 3.9, the number of Grammes in 1 drachm; and to convert Grammes into Apothecaries' drachms we divide the number of Grammes by 3.9. The same rule applies to the conversion of Apothecaries' ounces into Grammes and Grammes into ounces, the multiplier and divisor being 31.1, the number of Grammes in I ounce. Volumes. To convert minims into the corresponding metric equivalents, multiply the number or fractions of minims by .06, this being the equivalent in Cc. of 1 minim; and to convert the metric quantities into the corresponding equivalents in minims, divide the metric quantity by .06. To convert fluidrachms into Cc., multiply the number of drachms by 3.75, the number of Cc. in 1 fluidrachm; and to convert Cc. into fluidrachms, divide the number of Cc. by 3.75. To convert fluidounces into Cc., multiply the number of ounces by 30. Cc., the equivalent of 1 fluidounce; and to convert Cc. into fluidounces, divide the number of Cc. by 30. For convenience of ready reference and to facilitate computation the following tables are subjoined: Various methods have been proposed for adapting the metric weights to our apothecaries' weights used in prescription writing without entailing calculations in fractions. The method of taking 32 Grammes as equivalent to one troy ounce, and 30 Cc., or fluid. Grammes, as equal to one fluidounce, seems to be the least objectionable. These equivalents are shown in the following: 328 4. Gm. = I drachm. 32 Gm. 30 Cc. = I ounce ; = 3.75 Cc. The exact metric equivalent of 1 grain is obtained by dividing the unit by the Gramme equivalent in grains; thus, 1. 0.0648 Gramme (or 6 centigrammes). 15.432 The metric equivalents of all the other denominations may be obtained by multiplying the grain equivalent by the number of grains in one drachm; the number of drachms in a troy ounce, etc. The following exact Gramme equivalents are thus obtained: I grain. I drachm. I ounce av. 1 ounce troy. 1 lb troy. 3.888 28.349 31.103 373.250 i lb av. To convert avoirdupois or troy into metric weights, the equivalent of the Gramme in grains-15.432-should be remembered, as it serves the purpose of a basis for obtaining the equivalent of all the higher denominations. Ounces, Apoth., Table of Metric Equivalents of Ounces (Apoth., Av., and Fluid) in Grammes and Cubic Centimeters. It will be noted that in the Pharmacopoeia of 1890 the Gramme (Gm.) and the Cubic Centimeter (Cc.) are the only metrical terms used. The reason of this is simply that these two terms express sufficiently the quantities ordinarily handled, the remaining ones being excluded to avoid confusion, Grammes and Cubic Centimeters standing as perfect equivalents of ordinary weights and measures, as the foregoing tables indicate. PHARMACEUTICAL PREPARATIONS. PREPARATIONS made by the pharmacist are called pharmaceutical preparations. Nearly one-half of the articles of the United States. Pharmacopoeia are pharmaceutical; formulas being given for their preparation, they are intended to be made in the pharmacy. A still greater number are unofficial, being chiefly such as are made according to the formulas or prescriptions of eminent medical practitioners and teachers. Such of the latter as have attained. general use and proved of value have been incorporated in the National Formulary, a work published under the direction of the American Pharmaceutical Association. The importance of having a uniform standard for the preparation and strength of this class of medicines has long been recognized, instead of the variation in strength and product inseparable from a number of manufactures with the consequent multiplicity in processes and formulas. These preparations of the National Formulary, designated N. F., are included in this work, following the official preparations (U. S. P.) of the classes to which they belong. The pharmaceutical preparations may be divided as follows: I. Solutions. II. Liquid Mixtures-Internal. III. Extractive Preparations-Liquid and Solid. IV. Mixtures of Solids-Internal. V. Mixtures for External Use-Liquids and Solids. These groups are each divided into a number of Classes, each class having a distinct Latin title by which its members, or individual preparations, are officially designated and alphabetically arranged in the U. S. P. In addition to the Latin and English titles, each class is also known by an English name, besides various synonyms. There are altogether 34 of these Classes official, besides a number unofficial. I. The Solutions are divided, according to the character of the solvent, into Official number. 19 24 25 23 Ethereal: Oleoresina-Oleoresins IV. Mixtures of Solids-Internal: Pulveres-Powders Trituratio-Trituration Sales effervescentes-Salts, effervescent Confectiones-Confections. Trochisci-Troches Massa-Masses . Pilula-Pills. . V. Mixtures of Solids-External: Liquid: Linimenta-Liniments Oleata-Oleates. Collodia-Collodions. Solid: Unguenta-Ointments Suppositoria-Suppositories. Charta-Papers. Total |