weights of the denomination of grammes. The decimal system is now employed almost to the exclusion of others in science, and the United States Coast Survey has adopted it in its work. As all the formule published in Continental journals are based on the metric system, the following tables will prove of value to those who may have occasion to use the processes of their foreign associates. In order to express the decimal proportions, the following prefixes are used: Subdivision. Milli (from Millesimus), meaning a thousandth. Deci ( "Decimus) 66 a hundredth. It may assist the memory to observe that the terms for multiplying are Greek, and those for dividing, Latin. Measures of Length. One Myriametre = 10,000 Metres. 10 Metres. the ten millionth part of a quarter of the meri dian of the earth. the tenth part of one Metre, or 0.1 Metre. The unit of length. Weights. One Myriagramme = 10,000 Grammes. = One Kilogramme One Decigramme One Milligramme One Myrialitre One Kilolitre One Decalitre One LITRE2 One Decilitre One Centilitre One Millilitre 1,000 Grammes. 100 Grammes. 10 Grammes. the weight of a cubic centimetre of water at its maximum density, 4° C. the tenth part of one Gramme, or 0.1 Gramme. the hundredth part of one Gramme, or 0.01 Gramme. the thousandth part of oue Gramme, or 0.001 Gramine. Measures of Capacity. = 10 cubic Metres, or the measure of 10 Milliers of water. = 1 cubic Metre, or the measure of 1 Millier of water. = 100 cubic Decimetres, or the measure of 1 Quintal of water. = 10 cubic Decimetres, or the measure of 1 Myriagramme of water. = 1 cubic Decimetre, or the measure of 1 Kilogramme of water. = 100 cubic Centimetres, or the measure of 1 Hectogramme of water. = 10 cubic Centimetres, or the measure of 1 Decigramme of water. = 1 cubic Centimetre, or the measure of 1 Gramme of water. Relation of Weights of the U. S. Pharmacopoeia to Metrical Weights. A comparison between the metric system and that adopted in our own Pharmacopoeia may also be made, exhibiting at a glance the convertibility of one into the other. It is not probable that the whole of the French system will ever come into common use; in other words, that the refinement of decimal division will ever be closely followed in the writing of prescriptions. If the prescriber The unit of weight. 2 The unit of capacity. will restrict himself to the use of the gramme and the centigramme, or the gramme alone, to express integral and fractional quantities approximately, he will avoid the apparent confusion that seems to attend the employment of the decimal system to its minutest ramifications. Drachms, Ounces, and Pounds in Equivalent Metrical Weights. Relation of Metrical Measures to Measures of the U. S. Approximate Conversion of Ordinary Measures into Gramme Weights (Metric System). As a matter of convenience in the writing of prescrip tions containing fluid ingredients, the following table will be found of considerable importance for reference. As will be seen, it is arranged to include the estimated valuation, in the metric system, of menstrua or fluids of dif ferent densities, in quantities varying from a minim to four fluidounces. It forms a fitting sequel to the tables of weights and measures already given: Approximate Conversion of Measures into Gramme Weights.' Amer. Journal of Pharmacy, Feb. 1877, p. 92, by Prof. J. M. Maisch, in continuation of an article in the same number, p. 49, chiefly in defence of the expression of liquid preparations by metric weights. 2 Including spirits, tinctures prepared with alcohol, fixed and volatile oils. Including waters, fluid extracts, and tinctures prepared with diluted Including glycerine and the syrups. alcohol. |