The fact that citric acid easily parts with a molecule of water should always be borne in mind, and, therefore, undue heat should not be used in evaporating a solution of citric acid or of its salts. In fact, the evaporation should take place in vacuo. Dose.-500 milligrammes (8 grains). DRUGS CONTAINING FRUIT ACIDS As this opens the subject of crude drugs, a few words of introduction may be advisable. Vegetable drugs consist of whole plants, plant parts, or plant excretions, in other words, are portions of that collection of cells called a plant. Knowledge of plants forms the science of botany, and a full discussion of this science is clearly beyond the limits of this work; hence the student is referred to list of standard text-books given in the Preface. To explain the "official definitions" (p. 24) of the drugs that must be considered in this book a slight résumé of the important plant parts is in order and is here given, fuller details of peculiar cases being considered under drugs illustrative of each case. The study of vegetable drugs-of the plant parts used in medicineforms that branch of knowledge called organic materia medica, and even this in its complete form is beyond the province of this work, reference to the leading text-books on the subject being found in the Preface. In the study of materia medica, drugs are usually grouped as belonging to the several classes of plant parts-roots, stems, rhizomes, tubers, woods, barks, leaves, bulbs, herbs, flowers, fruit, and seeds—hence it may be well to define these parts (or organs) at this place. Roots A root is that part of the plant axis that does not bear leaves. are not always under ground; thus, ivy has roots above ground that aid the plant in climbing. A stem is that portion of the plant axis which does bear leaves. All stems are not above ground; the so-called "roots" of the violet or of Solomon's seal, which run horizontally under ground, are stem parts, for the leaves spring directly from them. A rhizome is that stem part which lives under ground. The violet stem part just mentioned is an example of a rhizome. A tuber is a thickened underground stem, used as a reservoir for starch. Example, the Irish potato. In the case of some tubers, they more closely resemble roots than stems, and are then called tuberous roots; an official example of such as is found in aconite. Stems of large plants like trees are called trunks, and such a trunk can be roughly divided into the central part, called the wood, and the outer, more or less corky layer, called the bark. Leaves are expansions of the stem tissue arranged regularly on the stem. Ordinarily leaves perform the function of respiration or breathing, playing an important part in the conversion of carbon dioxide, which they absorb from the air, into starch, sugar, and cellulose. Bulbs are collections of underground leaves attached to a stem which consists of nothing more than a conical disk from beneath which the rootlets project. The onion is a good example of a bulb. The difference between a tuber and a bulb may well be given here. An example of a tuber is the Irish potato, and as the example of a bulb the onion will be taken, and even slight examination will show that these two are different. Both grow underground, and neither is a root; yet they are not the same. A bulb, like a tuber, is an underground stem, but it goes farther, since it also includes distinct underground leaves. Thus, in the onion, the thick, juicy scales are the underground leaves, and all there is of the stem is the hard little base from which the rootlets grow and to which the scales (leaves) are attached. Herbs represent the whole dried plant, usually deprived of its roots. Flowers are leaf modifications which perform the function of reproduction, the special organs for this purpose being the ovary—the female organ and the anther-the male organ. The fertilized ovary develops within itself— Seeds, which are organisms containing a germ-the beginning of a new plant-provided with sufficient nourishment to support it during the first days of its sprouting. Fruits represent the ripened ovary and its appendages. The appendages vary from a thin, chaff-like ovary wall, in anise, to the large luscious "meat" and thick green rind of the watermelon. Chemically, drugs consist of many substances; those that are plant organs consisting, histologically, of cell-wall and cell-contents, drugs that are exudations from plants being usually entirely cell-contents. This cell-wall, which consists of cellulose, wood, bast, or cork, according to its development is generally spoken of pharmaceutically as "fibrous tissue." The cell-contents consist of a vast number of bodies, such as alkaloids, glucosides, neutral principles, oils (volatile or fixed), tannin, resin, gum, starch, sugar, etc. The last four are found in almost all plants, while the others are more sparingly found, and constitute the active principle of the specific drug under consideration. This leads to the classification of drugs into alkaloidal drugs, glucosidal drugs, astringent drugs, etc. In the consideration of every drug on the pages which follow the constituents will be an important feature study, and let it be here frankly stated that under constituents will be given only those which make the drug of value. Thus in considering alkaloidal drugs a continuous repetition of "gum, starch, and sugar" will be omitted, reference being made to these constituents only when they play an important rôle. Rhus Glabra (U.S.P. VIII; N.F. IV) are dried sumac berries. These enjoy some vogue as a remedy for sore throat; being made into an infusion, which is used as a gargle. Tamarindus (U.S.P. VIII; N.F. IV), or tamarind, is a preserved pulp of the fruit of Tamarindus indica and is frequently found in commerce mixed with molasses. Tamarinds are used as a refrigerant and laxative. A drink from tamarinds and cream of tartar is popular in the south for "thinning the blood." Dose.-15 grammes (240 grains). Limonis Succus (U.S.P. VIII), or lemon juice, is the commercial source of citric acid. Note that the original "neutral mixture" (Mistura Potassii Citratis, p. 418) was made by neutralizing lemon juice with potassium bicarbonate. It is a refrigerant and was formerly used on shipboard as a preventive of scurvy, a loathsome disease produced by a steady diet of salt meat. It is given in doses of 1 fluidounce. Succus Citri, N.F., or lime juice, is expressed from the lime fruit, Citrus medica acida. From it is prepared succus citri et pepsinum, N.F., which is made by mixing 400 mils of glycerite of pepsin with 600 mils of lime juice. BIBLIOGRAPHY Acetone. (History) Liebig, A., 1, 1832, 223; Dumas, Ann. chim. phys., [2], 49, 1832, 208; Bridges, A.J.P., 10, 1838, 202. (Manufacture) Squibb, A.J.P., 67, 1895, 144 and J. Am. Ch. Soc., 18, 1896, 231. (Reactions) Meyer and Janny, B. 15, 1882, 1324; Tollens, B., 15, 1882, 1635; Grimm, A., 157, 1871, 262. Sulphonal. (Manufacture) Anon., Am. Dr., 18, 1889, 209. (Tests) Ritsert, Ph. Zt., 33, 1888, 312. Trional. Fromm, A., 253, 1889, 150; Spitzer, A.Ph.A., 41, 1893, 535. Lactic Acid.-(Manufacture) Boutroux, A.Ph.A., 27, 1879, 460; Claflin, Jl. Soc. Ch. Ind., 16, 1897, 516. (Uses) Anon., Ph. Jl., [3], 7, 1876, 116. Glycerin. (History) Pelouze, Ann. chim. pharm., 19, 1836, 210 and 20, 1837, 46; Würz, Ann. chim. phys., [3], 43, 1855, 492. (Manufacture) Shinn, A.J.P., 22, 1850, 124; Carpenter, Jl. Soc. Ch. Ind., 2, 1883, 98; Shoemaker, Dr. Circ., 9, 1866, 7; Warner, A.Ph.A., 58, 1910, 341; Tilghman, U.S. Reports, No. 102, p. 707; Stendorf, Ap. Zt., 30, 1915, 500. (Properties) Crookes, Ch. News, 15, 1867, 26. Acrolein-Hübner and Geuther, A.J.P., 32, 1860, 449; Senderens, Comp. rend., 151, 1910, 530; Bergh, Jl. prakt. Ch., 79, 1909, 351. Nitroglycerin.-(History) Sobrero, Comp. rend, 24, 1847, 247, MacDonald, Arms and Explosives, 19, 1911, 60. (Manufacture) Gofner, Ch. Ind., 34, 1912, 307. (Properties) Monroe, Am. Dr., 17, 1888, 37; Darapsky, C. A., 1, 1907, 1059. Glycerophosphates.-Robin, A.Ph.A., 42, 1894, 725; Rijn, C. A., 3, 1909, 357; Self, Ph. J., 80, 1908, 627; Dubois, Jl. Ind. Eng. Ch., 6, 1914, 122; Umney, Brit. Col. Dr., 1914, 69. Boroglycerin.-McElhenie, A.J.P., 54, 1882, 352. Chloreton.-Anon., Am. Dr., 36, 1900, 12; Anon., A.J.P., 79, 1907, 117. Butyl Chloral Hydrate.-(Manufacture) Hofmann, Ph. Jl., [2], 11, 1870, 720; Kraemer and Pinner, A., 158, 1871, 37. (Properties) Mason, A.J.P., 46, 1874, 150. (Uses) Liebreich, Ph. Jl., [3], 6, 1876, 666. Butyric Ether-Rice, Am. Dr., 16, 1887, 9. Banana Oil.-Anon., Merck's Rep., 15, 1906, 22. Succinic Acid.-(History) Agricola (1550) through Kopp, 4, 1847, 361. (Structure) Schmitt, A., 114, 1860, 106. Malic Acid.-(History) Scheele (1785), Thorpe's Dict., 3, 1912, 380. Schmitt, A., 114, 1860, 106. (Structure) Asparagin. (History) Boutron-Chalard and Pelouze, Jl. de ph., 19, 1833, 208. (Structure) Dessaignes, A.J.P., 22, 1850, 245. Tartaric Acid.—(History) Wootton, 1, 1910, 371; Arny, Am. Dr., 38, 1901, 3; X-rayser, Am. Dr., 58, 1911, 36. (Structure) Liebig, A.J.P., 32, 1860, 347; Schmitt, A., 114, 1860, 106; Kolbe, A., 113, 1860, 317; Van t'Hoff, Bull soc. chim., [2], 23, 1875, 298. (Manufacture) Hölbing, J. Soc. Ch. Ind., 15, 1896, 712; Pasteur, A.J.P., 25, 1853, 250. (Properties) Pasteur, A.J.P., 26, 1854, 55. Amyl Alcohols.-Cahours, A.J.P., 11, 1839, 260; Pasteur, A., 96, 1855, 255. Amyl Nitrite.-(Manufacture) Maisch, A.J.P., 43, 1871, 146; Nietsch, A. Ph.A., 29, 1881, 299. (Properties) Taylor, Jl. A.Ph.A., 3, 1914, 1327. (Uses) Guthrie, A.J.P., 42, 1870, 468. Valeric Acids.-(History) Trommsdorf, A.J.P., 6, 1834, 351. (Manufacture) Dumas and Stass, A., 35, 1840, 145; Duclaux, Am. Dr., 16, 1887, 169; Mossler, Ph. Jl., 86, 1911, 175; Stahlmann, A.Ph.A., 17, 1869, 248. (Properties) Erlenmeyer and Hell, A., 160, 1871, 264, Schmitt and Sachleben, A., 193, 1878, 87; Hager, A.J.P., 52, 1880, 134. Valine.-Clark and Fittig, A., 139, 1866, 199. Tricarballylic and Aconitic Acids.-Pawolleck, A., 178, 1875, 153 and 167. Citric Acid.—(History) Grimaux and Adam, Comp. rend., 90, 1880, 1252, (Manufacture) Flückiger, Arch. d. Pharm., 227, 1899, 1065; Buchner and Wüsterfeld, C. A., 3, 1909, 1994. Rhus Glabra.-Rogers, A.J.P., 7, 1835, 56; Watson, A.J.P., 25, 1853, 193. CHAPTER XXXIX DERIVATIVES OF HEXANE THE following derivatives of hexane (C6H14) are of interest: Of the hexyl alcohols, seventeen are possible, but since none is of pharmaceutic value, they will not be noticed. By the oxidation of one of these alcohols, capronic acid, CH,(CH2)r COOH, is obtained. This capronic acid is a fatty acid discovered by Chevreul in 1824, and is found as an ester in coconut oil, Limburger cheese, and goat butter, and is cited merely because it is the only monobasic acid of hexane of pharmaceutic interest. Mannitol, C&Hs(OH) 6, is the hexatomic alcohol of hexane. It was isolated by Proust from manna in 1806, and is also found in minute traces in other drugs. The chief source of commercial mannite is manna, from which it is obtained by treating with boiling alcohol. From the alcoholic solution the mannite separates on cooling in small white crystals of sweetish taste. By careful oxidation it yields mannose, a variety of sugar, while oxidation with nitric acid yields saccharic acid. Dulcite and sorbite are isomeres of mannite, the former obtained by reduction of lactose (milk-sugar) and the latter by reduction of glucose. These three hexatomic alcohols yield ketone and aldehyde derivatives, which are of great importance, such as glucose, mannose, cane-sugar, starch, and cellulose. The formula of the first two is C6H12O6. Starch and cellulose (C6H1005) x. On examining these formulas it will be noticed that the hydrogen and oxygen atoms attached to the carbon atoms are present in exactly the same proportion as in water, viz., there are always twice as many hydrogen atoms as oxygen atoms. For this reason to this class of bodies was assigned the name "carbohydrates," although at present but little stress is laid on this characteristic. Carbohydrates.-While most carbohydrates are derivatives of hexane, some are found containing more or less carbon than six. Thus, arabinose is CH10O5. On the other hand, some contain seven carbon atoms, some eight carbon atoms, and some nine; but practically all the carbohydrates are derivatives of hexane. The hexane carbohydrates can be roughly grouped into three classes, the first having the form C6H12O6, which have representatives in glucose and dextrose; the second, being of double formula, C12H22O11, is found in cane-sugar; while the group C6H10Os has representatives in such wellknown bodies as starch, gum, and cellulose. The first examination of these bodies shows that one should be derived from the other, thus: The transition of starch or sugar into glucose is really performed by the adding of water (by chemical means). The reverse operation is not so simple a one, and has not been performed. On the other hand, one molecule of glucose minus one molecule of water gives the empiric formula of one molecule of starch or gum. As in the case cited above, the transformation of glucose into starch has not been accomplished, but the reverse operation, the conversion of starch into glucose, is performed by the very simple act of heating the starch with dilute sulphuric acid. It may be as well to state right here that the agent used for the molecular addition of water is usually diluted sulphuric acid, and the process of chemically combining water is called "hydrolyzing." On the other hand, if it is desired to remove water from the molecule of an organic substance, concentrated sulphuric acid is usually the agent employed, when it is said to act as a "dehydrator." The formula, C6H12O6, it will be noticed, differs from the formula of mannitol, CH1406, by containing two atoms of hydrogen less. It will be also noticed that this is the difference between the formula of an ordinary alcohol and its aldehyde or ketone, and it is really true that C6H12O is an aldehyde or ketone derivative of the hexatomic alcohol, CH(OH). The carbohydrates are called aldoses, or ketoses, according as the alcohol group has been changed to an aldehyde or a ketone, though some are of more intricate composition. The carbohydrates can best be studied by taking up three groups in their regular order, viz.: Those having formula C6H12O6, or monosaccharides (monoses) C12H22O11, or bisaccharides (bioses). THE MONOSACCHARIDES (C6H12O6) These are bodies of more or less sweetness, and all possess optical activity, that is, all deviate the ray of polarized light either to right or left, except the synthetic inactive varieties. According to Van t'Hoff's rule, each active substance should contain at least one asymmetric carbon atom, and investigation has shown that this is true in every case. Several syntheses of these bodies have been accomplished; thus paraformaldehyde cooked with milk of lime gives acrose; formaldehyde cooked with milk of lime gives a mixture of formose and acrose (p. 585). Likewise dibromide |