PHYSIOLOGICAL ACTION AND THERAPEUTICS. Ginger is sialagogue when chewed, sternutatory when inhaled, and externally a rubefacient. Internally it is a grateful stimulant and carminative, produces a sensation of warmth at the epigastrium and promotes the expulsion of flatus. It is employed as a carminative in colic, as a masticatory to increase the secretion of saliva and in relaxed conditions of the throat, also internally in atonic dyspepsia, to relieve flatulence, and as an adjunct to purgative agents to correct their griping properties. The syrup is in common use as a flavoring adjuvant in prescriptions. PART II. 415 PHARMACY AND PRESCRIPTION WRITING. Pharmacy (ápμazov, a medicament),-may be defined as the art of selecting and preserving medicines, and preparing them for administration. It may be divided into Official or Galenical Pharmacy,-dealing with the processes and preparations of the Pharmacopoeia; and Extemporaneous or Magistral Pharmacy,-which includes the operations of compounding and dispensing remedies as directed by the prescriptions of physicians. PHARMACOPOEIAS AND DISPENSATORIES. A Pharmacopoeia is an official list of the drugs and their preparations recognized by the medical profession of a certain country. In foreign countries the Pharmacopoeias are published under government auspices and have the force of a legal standard; in the United States its publication is left to the medical and pharmaceutical professions and is revised every ten years by a convention called for that purpose. The principal official Pharmacopoeias, with their dates of latest revision or additions, are the following, viz.— Pharmacopoeia of the United States of America, 1882. Pharmacopoeia Germanica, 1882. Codex Medicamentarius (Pharmacopée Française), 1884. Besides the above there are the Russian (P. Rossica, 1880); the Austrian (P. Austriaca, 1869); the Swedish (P. Suecica, 1869); the Norwegian (P. Norvegica, 1879); the Danish (P. Danica, 1868, 1874, 1876); the Belgian (P. Belgica, 1881); the Swiss (P. Helvetica, 1872, 1876); the Spanish (F. Española, 1865); the Portuguese (P. Portugueza, 1876); the Hungarian (P. Hungarica, 1871); the Netherlands (P. Neerlandica, 1871); the Roumanian (P. Româña, 1862); the Finnish (P. Fennica, 1863); the Greek (P. Hellenica, 1868); the Mexican (Nueva Farmacopea Mexicana, 1884); and the Pharmacopoeia of India, 1868, 1869. Italy, Chili and Japan are each about to issue a national pharmacopoeia. A Dispensatory is a commentary on one or more pharmacopoeias, giving in extenso the physical and medicinal history of the drugs and preparations, together with their doses, physiological action and therapeutics, and includes similar information about many drugs which are not official in any pharmacopoeia, but are of occasional use or general interest. A dispensatory is a private publication, of authority according to the reputation of its author. The principal dispensatories are veritable drugencyclopædias, so elaborately do they deal with every subject embraced therein. Those of acknowledged value are The Dispensatory of the United States of America, by Drs. Wood and Bache, of Philadelphia, 16th edition, edited by Wood, Remington and Sadtler. Philadelphia, The J. B. Lippincott Company. 1888. The National Dispensatory, edited by Drs. Stillé and Maisch. 4th edition. Philadelphia, Lea, Bros. & Co. 1887. The American Dispensatory, by King & Lloyd, Cincinnati, is the recognized authority of the "eclectic" practitioners. A Companion to the U. S. Pharmacopœia, by Drs. Oldberg and Wall. 2d edition, New York, Wm. Wood & Co.-is an excellent book, but not so exhaustive as the others in its method of treating the subjects embraced in it. A Companion to the British Pharmacopeia, by Peter Squire, is the standard student's text-book on drugs in England, but in no degree compares with the United States or National Dispensatories. THE CONSTITUENTS OF VEGETABLE DRUGS. The constituents of vegetable drugs may be classified as soluble and insoluble, the first group containing those ingredients which may be. extracted by suitable menstrua, the second such as resist the action of all ordinary solvents. THE SOLUBLE CONSTITUENTS Comprise both inert and active principles, the inert being chiefly starch, gum and pectin, which may be readily separated by water. The active principles are alkaloids, acids, salts, glu. cosides and other neutral principles, volatile oils, resins, etc. Some few of these may be extracted by Water alone (e. g., Morphine), and in some cases the addition of acids or alkalies to the water will effect the chemical solution of many ingredients which are insoluble in water alone. As a rule, however, Alcohol is the most generally applicable of all simple solvents, but from its hardening the cell-membranes instead of softening them it prevents the osmosis of their contents. Drugs subjected to alcoholic or ethereal menstrua should have, their cells thoroughly broken or torn, so that the solvent may be brought into actual contact with the principles contained in them. The degree of disintegration required depends upon the size of the cells, ducts, tubes, intercellular spaces, etc., in which the active principles are enclosed. A very finely powdered state is however open to objection from the packing of the particles together into an almost impenetrable mass when treated by the solvent. The average size of vegetable cells is about of an inch, while resin cells and other cavities are larger, averaging perhaps about inch. The Pharmacopoeia prescribes in each instance the degree of fineness of the THE CONSTITUENTS OF VEGETABLE DRUGS. 417 powdered drug employed in making certain of its preparations, or its bruising, slicing, etc., when such operations will answer. [Compare the article on Comminution in the following section.] Alkaloidea, Alkaloids, (termination, -ina, -ine,) are natural principles existing in plants, and extracted therefrom by chemical art. They are organic bases, forming salts with acids, and regarded as compound ammonias, products of albuminous decomposition in the plant-cells during the process of growth. Like ammonia, they all contain N, with C and H; most of them also containing O, though a few are devoid of the latter element, occurring as oily liquids,-e. g., Nicotine, Coniïne, Sparteine, Piperidine, Lupuline, Lobeline, Muscarine. Alkaloids are generally insoluble in water, but soluble in alcohol; and their salts are more soluble in water than in any other liquid. They are easily decomposed by alkalies or alkaline carbonates; and are precipitated from their solutions by a solution of Iodine in Iodide of Potassium, by Potassio-mercuric Iodide, and by Picric, Phospho-molybdic and Phospho-tungstic Acids. They generally have a powerful physiological action, and their official names. always end in—ina, (—ine). There are 15 alkaloids official, either under their own names or under those of one or more of their salts. Of the latter there are 8 Sulphates, 4 Hydrochlorates, and 1 each Bisulphate, Acetate, Hydrobromate, Salicylate and Valerianate. The official alkaloids are as follows, viz. — Unofficial, but Important Alkaloids are the following, viz.— Veratrina. Gelsemine. Kairine. Muscarine. Pelletierine. Thalline. Glucosidea, Glucosides, (terminations, -inum, -in),-are organic compounds, belonging to the group of Neutral Principles which exist in plants; and which are resolved into glucose and some other principle, by the action of reagents or natural ferments. Few, if any, of these compounds, contain any N,-but among them are some very active agents. The official glucosides number six, and like other neutral principles, are designated by titles which end, in Latin in-inum, (English, -in), viz. Chrysarobinum, (Chrysarobin). Elaterinum, (Elaterin). Picrotoxinum, (Picrotoxin). Glycyrrhizinum, (Glycyrrhizin). Santoninum, (Santonin). Besides these, there are several other substances recognized by pharmacopoeial names which terminate in -inum, -in, but which have no relationship to the group of Glucosides. They are the following, viz.— Benzinum, Benzin,-A distillate consisting of hydrocarbons. Benzoinum, Benzoin,-A balsamic resin. Chinoidinum, Chinoidin,--A mixture of Cinchona alkaloids. Pyroxylinum, Pyroxylin,-Soluble gun-cotton. THE INSOLUBLE CONSTITUENTS are cellulose, lignin and sclerogen, which make up the cell-walls of vegetable substances, and are extremely intractable. OFFICIAL PHARMACY. OFFICIAL OPERATIONS. The official operations are those processes which are directed in the pharmacopoeia to be used in the preparation of medicines. Many of them are processes which are common to both chemistry and pharmacy, as precipitation and crystallization,-while others are peculiar to pharmacy, as percolation, trituration, etc. The most important of the pharmaceutical operations are briefly described below; for full details of the various apparatus used the student is referred to the more exhaustive treatises on Pharmacy. Vaporization includes the various operations by which volatile matters are separated from fixed substances or from other matters which are less volatile, heat at varying temperatures being the agent used. The operations under this head are-Evaporation, Distillation, Desiccation, and Sublimation. EVAPORATION in Pharmacy is the process by which the more volatile constituents of a liquid are driven off by heat for the purpose of reducing its volume or of purifying it, as in the preparation of extracts and fluid extracts, the crystallization of salts, etc. The vessels used should be shallow so as to expose a large surface of the liquid to the atmosphere. The heat used may be regulated by a water-bath, a steam-bath or sand-bath, and ordinarily should be kept below but near to the boiling-point of the liquid treated. As organic substances are usually injured by long heating, small portions only of vegetable preparations should be subjected to this process, and the liquid should be frequently stirred in order to hasten the |