(bark), Radix (root) are always used in the singular, while Folia (leaves) and Flores (flowers) are invariably used in the plural.

The OFFICIAL ENGLISH NAME need not necessarily be a literal translation of the official Latin name, in fact it seems very desirable that a drug should have two distinct names officially recognized, the one confined to the official Latin title, admirably adapted to abbreviation and use in prescriptions, while the other may be employed in the ordinary course of conversation and is intended for use in commercial transactions and the daily routine of business, as Nutmeg for Myristica, Brandy for Spiritus Vini Gallici, Black Haw for Viburnum Prunifolium, Pale Rose for Rosa Centifolia, Cascara Sagrada for Rhamnus Purshiana, Pumpkin Seed for Pepo, etc. Occasionally the English name is used in the plural while the Latin name is always used in the singular number, as Cantharides for Cantharis, Cloves for Caryophyllus. In the case of chemical compounds the official English name often indicates with greater precision the true composition, as Solution of Mercuric Nitrate for Liquor Hydrargyri Nitratis, Ferrous Sulphate for Ferri Sulphas, Ferric Citrate for Ferri Citras, etc.

In a large number of instances a second English name, which long custom has demanded shall not be ignored, is given as a synonym in the title, although its origin may be unscientific and its retention not in strict accord with the systematic nomenclature of the Pharmacopoeia; the synonym invariably follows the official English. name and is enclosed in brackets. Among the prominent synonyms found in the Pharmacopoeia are Calomel for Mild Mercurous Chloride, Epsom Salt for Magnesium Sulphate, Balm for Melissa, Labarraque's Solution for Solution of Chlorinated Soda, Witch-hazel for Hamamelis, Sweet Flag for Calamus, Black Draught for Compound Infusion of Senna, Red Precipitate for Red Mercuric Oxide, Griffith's Mixture for Compound Iron Mixture, Tully's Powder for Compound Powder of Morphine, Citrine Ointment for Ointment of Mercuric Nitrate, Basilicon Ointment for Resin Cerate, etc.

Several of the official synonyms have been added for the purpose of more clearly expressing the true chemical character of the compounds for which they are used, than is possible with the official Latin or English names, as Phenylacetamide for Acetanilid, Sodium Paraphenolsulphonate for Sodium Sulphocarbolate, Phenyl Salicylate for Salol, Beta Naphtol for Naphtol, etc.

The OFFICIAL DEFINITION determines the source and character of the drug or chemical as recognized by the Pharmacopoeia. In the case of vegetable drugs the botanical name of the plant yielding the drug is composed of two parts, the generic name and the specific name, always written in the same order of sequence; the first or generic name is invariably begun with a capital letter, and is usually employed as the official Latin name of the drug, while the specific name is only begun with a capital letter when derived from a generic name, as in Cytisus Scoparius, or from a proper name, as in Garcinia

Hanburii, or when it is indeclinable, as in Aspidosperma Quebrachoblanco. The necessity for using the full botanical name of the plant to indicate the source of the official drug is clearly shown in the case of the genus Lobelia, of which the Pharmacopoeia recognizes only the species inflata, although two others, syphilitica and cardinalis, are also well known; of the genus Grindelia two species, robusta and squarrosa, are recognized as furnishing the official drug. Accompanying the botanical name of the plant is the name of the author, printed in Roman type, and following it, enclosed in parentheses, the natural order to which the plant belongs, thus, Veronica virginica, Linné (nat. ord. Scrophulariacea).

In the case of official chemicals it becomes necessary to establish the identity of the compound by expressing its exact composition by means of symbolic formulas; thus in the case of sodium phosphate the formula Na2HPO,+12H2O specifies clearly the kind officially recognized by that name; other varieties of sodium phosphate, such as Na,HPO,+6H2O, Na2HPO,, or even NaHPÒ, or Na,PO, can therefore not be used in prescriptions or official preparations. The official definition of alumen, alum, is Al,K,(SO,),+ 24H2O, showing that the pharmacopoeial alum is potassium alum, or, more strictly speaking, potassium and aluminum sulphate; since commercial alum, as a rule, is ammonium alum, the official definition is important, and necessary to establish the chemical character of the compound to be used as alum in prescriptions and official preparations. The Pharmacopoeia recognizes as magnesium carbonate a compound for which the symbolic formula 4MgCO,.Mg (OH)2+5H2O is given, which shows it to be not true magnesium carbonate, but a substance containing four molecules of magnesium carbonate, one molecule of magnesium hydroxide, and five molecules of water. The official definition for pure morphine, CH1NO,+ H2O, recognizes a compound containing one molecule (in this case 5.94 per cent.) of water, and for pure quinine C20H2,N2O2+3H2O, a compound containing three molecules (in this case 14.28 per cent.) of water. Whenever water is expressed in a symbolic formula, as in the five cases above mentioned, it forms an integral part of that formula, and is shown to be an essential constituent of the official compound; in the majority of cases the presence of such water lends to the compound its power to assume the crystalline form, and is then known as water of crystallization, but when not so required it is known as water of hydration, as in the case of the official magnesium carbonate. Every symbolic formula is followed by a number which expresses the molecular weight of the compound, that is, the sum of the weights of the atoms of component elements; thus in the case of the official bismuth citrate, BiC,H,O,= 397.44, the molecular weight 397.44 is equal to the sum of the weights of all the atoms represented in the compound, namely, 1 atom of bismuth 208.9, 6 atoms of carbon = (11.97 x 6) 71.82, 5 atoms of hydrogen = (1 × 5) 5, and 7 atoms of oxygen (15.96 × 7) 111.72,

=

24

=

=

or 208.971.82 + 5 + 111.72 = 397.44; official sodium carbonate is given as Na,CO, + 10H2O= 285.45, in which case the weight of all the atoms of the crystalline compound, including the water, is accounted for in the molecular weight, 285.45, as follows: 2 atoms of sodium = 232 or 46, 1 atom of carbon = 11.97, 3 atoms of oxygen 15.96 X 3 or 47.88, ten times 2, or 20 atoms of hydrogen = 1 X 20 or 20, and 10 further atoms of oxygen = 15.96 × 10 or 159.6, or 46 +11.97 + 47.88 +20 + 159.6285.45. The number following simple elements expresses only the weight of a single atom, as bromine, Br 79.76, sulphur, S 31.98, etc. Atomic and molecular weights are of value in the proper construction of equations for the purpose of demonstrating chemical

reactions.

=

=

THE OFFICIAL DESCRIPTION. While the official definition is a brief but exact statement of the nature and source of drugs and of the composition of chemicals, the official description amplifies the definition by adding the physical characteristics of drugs, such as shape, size, odor, and taste, together with a statement of possible impurities and adulterations and means for their detection. For chemicals is added a clear account of their physical properties, their behavior toward different solvents, and such tests as shall enable the pharmacist to detect impurities and establish the fulfilment of pharmacopoeial requirements. The official description is always printed in small type, and forms a most valuable and important part of the Pharmacopoeia.

Dispensatories.

A dispensatory is a commentary on the Pharmacopoeia, and, as such, has become indispensable to both physicians and pharmacists. While the text of the Pharmacopoeia is confined to the definition and description of drugs and chemicals as well as to the official tests and requirements and accepted formulas for numerous preparations, much valuable additional information is given in the dispensatories, such as historical data, action, and uses, as well as doses of medicines, together with comments on and explanations of pharmaceutical and chemical processes. Besides the official drugs and chemicals, a large number of unofficial remedies and formulas are also treated in detail. Two dispensatories are published in this country: the United States Dispensatory, established in 1833, by Wood and Bache, which has now reached its seventeenth edition, and the National Dispensatory, established in 1879, by Stillé and Maisch, of which five editions have thus far been published.

CHAPTER II.

WEIGHTS AND MEASURES.

as

METROLOGY (from the Greek word erpov, measure, and 26yos, a discourse) is a study of the art and science of measurements applied to extension, volume, and weight of matter. Measure of extension may be either of length or of surface, while measure of volume or bulk applies to the cubic contents. Measure of weight is the determination of the gravitating force of bodies, that is, of their attraction by the earth toward its centre, such attraction bearing a direct relation to the quantity of matter contained in a body; hence weight is pressure exerted by a body upon a horizontal plane supporting it. True weight can only be obtained in vacuo, where the exact measurements of the force of gravitation cannot be interfered with by atmospheric pressure; all measurements of weight in any medium, such as air or water, must therefore give low results. Ordinary operations of weighing, being conducted in air, give apparent weight of the substance only.

Weighing and measuring being operations of daily occurrence in pharmacy which require care and exactness, a knowledge of the standards of weights and measures in use in this country and elsewhere is absolutely necessary. With more or less modification the standards at present in use in pharmacy in the United States and Great Britain are the same as those formerly employed by the Romans, and which in all probability were by them derived from the more ancient Greek nation. Three different systems of weights are at present employed in all English-speaking nations; namely, avoirdupois weight, apothecaries' weight and metric weight.

AVOIRDUPOIS weight, as its name would seem to indicate, is probably of French origin (avoir du poids, to have weight), and was no doubt introduced into Great Britain during the reign of the Norman dynasty; it first appeared in the English statute-books in 1335. Avoirdupois weight is employed in the sale of all commodities except precious metals and precious stones, hence drugs are always bought and sold by pharmacists by this system. In Great Britain avoirdupois weight is also employed in the formulas of the British Pharmacopoeia, and is now known there under the name of Imperial weight. In 1824, the value of an avoirdupois pound was defined by law in England to be 7988 of the old standard troy pound. The divisions of avoirdupois weight are the pound, ounce, drachm, and grain, which are symbolized by the following characters: b, oz.,

drm., gr.; each pound contains 16 ounces and each ounce 16 drachms or 437 grains. The term drachm is rarely employed, quantities less than an ounce being usually designated by common fractions, such as oz., oz., oz., or in grains. The avoirdupois pound containing 7000 grains (437 × 16) is the only pound used in the United States and Great Britain except at the mints; the standard pound is the equivalent in weight of 27.7015 cubic inches of distilled water at 62° Fahrenheit and normal barometric pressure.

The

APOTHECARIES' weight was probably derived from troy weight, which latter was introduced into Great Britain, by merchants from Lombardy, toward the close of the thirteenth century; it is employed altogether in the writing and compounding of physicians' prescriptions, and is divided into grains, scruples, drachms, and ounces, of which 20 grains are equal to 1 scruple, 3 scruples are equal to 1 drachm, and 8 drachms are equal to 1 ounce. apothecaries' ounce is of the same value as the now obsolete English troy ounce. The following symbols are employed to designate the divisions of apothecaries' weight, and always precede the number indicating the quantity intended, which is expressed in Roman numericals, thus, gr. j, for one grain, Dij, for two scruples, 3iij, for three drachms, 3iv, for four ounces. As far back as 1266, during the reign of Henry III., a statute was enacted in England which provided that an English silver penny, called a sterling, round and without clipping, should equal in weight 32 wheat-grains, well dried and taken from the centre of the ear, and that of such pence 20 should make 1 ounce, and 12 ounces 1 pound. About 1497, in the time of Henry VII., the weight of the silver penny, however, was changed to the equivalent of 24 wheat-grains. These statutes clearly indicate the origin of the pennyweight and the troy system, from which the apothecaries' weight, still in use at the present day, was subsequently derived. The choice of wheat-grains from the centre of the ear arose from a desire for uniformity in size and weight, as did likewise the directions to employ the grain well dried. The adoption of troy weight by physicians and pharmacists dates back to 1618, when the first London Pharmacopoeia was compiled. In 1826, Imperial measures and standards were legalized in England, and in 1827 exact copies of these standards were furnished the minister of the United States Government at London; namely, the standard yard, a bronze bar of 36 inches length, a brass troy-pound weight of 5760 grains, and a brass avoirdupois-pound weight of 7000 grains; copies of these standards were supplied to the different States in 1836 by Act of Congress. The length of the standard yard is determined by comparison with a pendulum beating seconds of mean time, in a vacuum, at the temperature of 62° Fahrenheit, at the level of the sea, in the latitude of London; the length of such a pendulum was found to be 39.13929 inches."

From what has been said above it is clear that every troy or apothecaries' ounce is heavier than the avoirdupois ounce by 421