containing acetic, formic, butyric, crotonic, capronic, propionic acids, acetone, methylic alcohol, furfurol, methylamine, pyrocatechin, and small quantities of empyreumatic oils and resins. 2. Tarry liquid, containing toluol, xylol, cumol, methol, mesitylene, pseudocumol, phenol, cresol, guaiacol, creasol, phlorol, and methylereasol, naphthalene, paraffin, pyrene, chrysene, retene, mesit. GASES.-Carbon dioxide, carbon monoxide, marsh gas, acetylene, ethylene, propene, and others.

Which are the most important of these? Charcoal, tar, acetic acid, acetone, methylic alcohol, and creosote.

ACIDUM ACETICUM, U. S.-Acetic Acid. HC,H,O,; 59.86. -A clear, colorless liquid, with a strong vinegar-like odor, purely acid taste, strongly acid reaction, composed of 36 per cent. absolute acetic acid and 64 per cent. water. Made by distilling oak wood at a temperature much less than that necessary to produce charcoal.

Acetic acid is also made by distilling vinegar, which, in turn, is made by oxidizing dilute alcoholic liquids. In Germany it is made by oxidizing alcohol, by pouring a very dilute alcoholic solution on beech wood shavings, which exposes a large surface to the air.

What two strengths of acetic acid are found in commerce? The official acid and No. 8 acid. The former has a sp. gr. of 1.048, the latter 1.040, and is 20 per cent. weaker. It is called No. 8 acid because it was formerly used in the proportion of 1 to 8, to make dilute acetic acid or distilled vinegar.

ACIDUM ACETICUM DILUTUM, U. S.-Diluted Acetic Acid. The liquid used as the menstruum for the official vinegars, containing 6 per cent. absolute HC2H2O2; sp. gr. 1.008. Made by diluting 100 Gm. acetic acid with 500 Gm. distilled water, to make 600 Gm.

ACIDUM ACETICUM GLACIALE, U. S.-Glacial Acetic Acid. HC,H,O2; 59.86.—A clear, colorless liquid, of a strong, vinegarlike odor, and a very pungent, purely acid taste. Somewhat below 15° C. (59° F.), a crystalline solid; nearly or quite absolute acetic acid; sp. gr., not higher than 1.058, at 15° C. (59° F.). Made by heating sodium acetate until the water of crystallization has been driven off, powdering the residue, and distilling it with concentrated sulphuric acid. The reaction is as follows:

PIX LIQUIDA, U. S.-Tar.-An empyreumatic oleoresin, obtained by the destructive distillation of the wood of Pinus Palustris and of other species of pinus. It is usually obtained as a by-product in the manufacture of charcoal or acetic acid. A thick, viscid semi-fluid, blackish-brown, heavier than water, transparent in thin layers, becoming granular or opaque by age; having an acid reaction, an empyreumatic terebinthinate odor, and a sharp, empyreumatic taste; slightly soluble in water, soluble in alcohol, in fixed or volatile oils, and in solution of potassa or of soda. Official Preparations.-Syrupus Picis Liquida, Unguentum Picis Liquida.

OLEUM PICIS LIQUIDÆ, U. S.—Oil of Tar.-- An almost color

less liquid, distilled from tar, soon acquiring a dark, reddish-brown color when exposed to the air; having a strong, tarry odor and taste and acid reaction; sp. gr. about 0.970.

Black Pitch.The residue left after the distillation of tar.

OLEUM CADINUM, U.S.-Oil of Cade. (Oleum Juniperi Empyreumaticum.)—A product of the dry distillation of the wood of Juniperus Oxycedrus. A dark brown, clear, thick liquid, having an empyreumatic odor and burning taste. Sp. gr. about 0.990.

CREOSOTUM, U. S.-Creosote.-An almost colorless or yellowishpinkish, highly refractive, oily liquid, turning to reddish-yellow or brown by exposure to light; penetrating, smoky odor; burning, caustic taste; neutral reaction; sp. gr. not below 1.070 at 15° C (59° F.).

Creosote is a production of the distillation of wood-tar, consisting, mainly, of the following phenols; guaiacol or oxycresol, CHO2, boiling at 200° C. (392° F.); creosol, CH10O2, boiling at 217° C. (422.6° F.); methylcreosol, CH12O2, boiling at 214° C. (417° F.) to 218° C. (424.4° F.); phlorol, CHO, boiling at 219° C. (426.2° F.).

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When wood tar is distilled, a solution of several layers is formed. The lower, oily layer is treated with K,CO,, to neutralize the acid present. Fractional distillation, with alternate treatment of the distillate with H2SO and KHO, to separate impurities, and final distillation, yields the product called creosote, which comes over between 205° and 220° C. (401o and 428° F.).

Nearly all of the liquid sold for creosote in the market is impure carbolic acid or coal tar creosote. It is distinguished from true wood creosote in the following manner: Creosote does not coagulate albumen or collodion. (For other tests, see U. S. P.)

Official Preparation.—Aqua Creosoti.

Products Resulting from the Natural Decomposition of Cellulin and Lignin and their Derivatives.

Coal. A fossil formation found in the earth, formed by the decomposition of cellulin, lignin, etc., under the changing influence of moisture, temperature, and pressure.

Coal Tar.-A residue left after the dry distillation of bituminous coal in the process of making illuminating gas. It consists of a large number of products in the forms of solids, liquids, and gases, a number of which form very valuable products in the arts.

NAPHTALINUM, U. S.-Naphtalin. C10Hg; 127.7. (Naphtalene.)-A hydrocarbon obtained from coal tar. Colorless, shining, transparent laminæ, having a strong, characteristic odor resembling that of coaltar, and a burning, aromatic taste; slowly volatilized on exposure to the air. Insoluble in water, but when boiled with the latter imparting to it a faint odor and taste. Soluble in 15 parts of alcohol at 15° C. (59° F.), and very soluble in boiling alcohol; also very soluble in ether, chloroform, carbon disulphide, and fixed or volatile oils. May be obtained by subjecting coal-tar to distillation, when it passes over after the coal naphtha. Frequently produced by dry distillation of organic bodies. Also known as coal-tar camphor, and employed to prevent the ravages of moth in woolen clothing.

NAPHTOL, U.S.—Naphtol. CoH,OH; 143.66. ( Beta-Naphtol.) A phenol occurring in coal-tar, but usually prepared artifically from naph talin. Colorless, or pale buff-colored, shining, crystalline lamina, or a white, or yellowish white, crystalline powder, having a faint, phenol-like odor and a sharp and pungent, but not persistent, taste. Permanent in the air. Soluble at 15° C. (59° F.), in about 1000 parts of water, and in 0.75 part of alcohol; in about 75 parts of boiling water, and very soluble in boiling alcohol. Also very soluble in ether, chloroform, or solution of caustic alkalies. Prepared by digesting p. naphtalin with 3 p. H2SO at 80° C. by which a- and B-naphtalin-sulphonic acids are produced; formula CHSO,H. These may be separated by Ba or Pb salts. When treated with H2SO, the a-acid passes into the ẞ, therefore, the latter acid is produced exclusively at high temperatures (160° C.). When fused with alkaline hydrates both of the acids yield their corresponding naphtols, known as a- and B-naphtols, respectively.

When naphtalin is digested with H2SO, two acids are formed, one of them being known as alpha-naphtalin-sulphonic acid. When this acid is heated with H2SO,, beta-naphtalin-sulphonic acid results. By fusing the latter acid with an alkaline hydrate, beta-naphtol (the official naphtol) is produced.

ACETANILIDUM, U. S.-Acetanilid. CH5NH.C2H2O; 134.73. (Phenylacetamide.)—An acetyl derivative of aniline, occurring in white, shining, micaceous, crystalline laminæ, or a crystalline powder, odorless, having a faintly burning taste, and permanent in the air. Soluble at

15° C. (59° F.), in 194 parts of water, and in 5 parts of alcohol; in 18 parts of boiling water, and in 0.4 part of boiling alcohol; also soluble in 18 parts of ether, and easily soluble in chloroform, melting at 113° C. (235.4° F.), and consumed without residue when ignited.

Acetanilidum, also known as antifebrin, is made by heating a mixture of aniline and glacial acetic acid to the boiling point; the cooled, congealed residue is purified by sublimation or recrystallization.

ACIDUM CARBOLICUM CRUDUM, U. S.-Crude Carbolic Acid.-A liquid consisting of various constituents of coal-tar, chiefly cresol and phenol, obtained during the fractional distillation of coal-tar. The portion coming over between 165° C., and 190° C. (329°-374°F.) is known as "dead oil because once deemed valueless. When dead oil is redistilled the product is Crude Carbolic Acid. If the latter is redistilled, water (principally) comes over, but when distillation is carried on between 165° to 185° C. (329°-365° F.) nearly pure and crystallizable phenol (carbolic acid) results; above this temperature 185° C. to 195° C. (365°-383° F.) the distillate consists mainly of cresol and other phenols, (uncrystallizable). At temperatures from 195° C. to 211° C. (383°-411.8° F.), cresol, CHO, and xylenol, CH1O, are obtained. A nearly colorless or reddish-brown liquid, of a strongly empyreumatic and creosote-like odor, having a benumbing, blanching, and caustic effect on the skin or mucous membrane, and a slightly acid reaction.

ACIDUM CARBOLICUM, U. S.-Carbolic Acid. C,H,HO; 93.78. (Phnol.)-Colorless, separate or interlaced, needle-shaped crystals, or a white, crystalline mass, sometimes acquiring a reddish tint; de

liquescent on exposure to moist air. It produces a benumbing, blanching, and caustic effect on the skin. It has a distinctive, slightly aromatic odor, resembling creosote; when diluted, a sweetish taste, with a slightly burning after-taste; faintly acid reaction; and is a product of the distillation of coal-tar between the temperatures of 180° C. and 190° C. (356°–374° F.).

Official Preparations.-Glyceritum Acidi Carbolici, Unguentum Acidi Carbolici.

RESORCINUM, U. S.-Resorcin. CH(OH)2; 109.74 (Resorci nol. Metadioxybenzol.)—A diatomic phenol, colorless, or faintly reddish, needle-shaped crystals or rhombic plates, having a faint, peculiar odor, and disagreeable, sweetish, and afterward pungent taste. Resorcin acquires a reddish or brownish tint by exposure to light and air. Soluble at 15° C. (59° F.), in 0.6 part of water, and in 0.5 part of alcohol; very soluble in boiling water or in boiling alcohol; also readily soluble in ether or glycerin; very slightly soluble in chloroform. Usually prepared by fusing sodium benzol disulphonate with caustic soda, but may be made in several other ways. It is a diatomic phenol isomeric with pyrocatechin and hydroquinone.

ACIDUM SALICYLICUM, U. S.—Salicylic Acid. HC,H ̧O; 137.67.-Fine, white, light, prismatic, needle-shaped crystals, permanent in the air.; free from odor of carbolic acid; having sometimes, a slight aromatic odor; sweetish and slightly acrid taste; acid reaction. Prepared by treating sodium phenol (or carbolate) with carbon dioxide. The sodium phenol is prepared by evaporating to dryness equal amounts of concentrated caustic soda solution and phenol; this is then heated to 100° C. (212° F.), while a stream of dry CO2 is passed over it. The temperature is gradually raised as soon as the phenol distills over, until it reaches 250° C. (482° F.), until no more phenol distills. Half of the phenol used remains in the retort, as sodium salicylate, while the other half distills over unchanged. The reaction is as follows:

The normal sodium salicylate thus obtained is then decomposed by HCl, and the salicylic acid is filtered out, washed and crystallized, or purified by sublimation and superheated steam or by dialysis.

SALOL, U. S.-Salol. CH¿C,H2O; 213.49. (Phenyl Salicylate.) -The salicylic ether of phenol. A white, crystalline powder, odorless, or having a faintly aromatic odor, and almost tasteless. Permanent in the

air.

Almost insoluble in water; soluble in 10 parts of alcohol at 15° C. (59° F.); very soluble in boiling alcohol; also soluble in 0.3 part of ether, and readily in chloroform, and in fixed and volatile oils. Prepared by heating salicylic acid with phenol in the presence of phosphorus pentachloride or phosphorus oxychloride; the elements of water are withdrawn by this action, and the phenol group is caused to unite with the salicylic radical.

AMYLACEOUS AND MUCILAGINOUS PRIN. CIPLES AND THEIR PRODUCTS.

AMYLUM, U. S.-Starch.-The fecula of the seed of Zea Mays, occurring in irregular, angular masses, which are easily reduced to powder of a white color; under the microscope appearing as granules, mostly very minute, more or less angular in form, and indistinctly striated, but with a distinct hilum near the centre. Inodorous and tasteless.

Starch is present in many drugs and is an important constituent of many vegetable foods. It is usually made from potatoes by separating the cellular substance from the starch, by grating and pressing the soft mass upon a sieve, the starch granules falling through. It may be, also, prepared from wheat or corn, by allowing the grain to ferment, which disintegrates it, and stopping the fermentation before the starch is affected. The quality of starch depends largely upon the quality and purity of the water used in washing it.

Chemical Composition of Starch.-It has the same chemical composition as cellulose, CH10O5, and is closely allied to it and its properties.

Office of Starch in the Vegetable Kingdom.-It is stored up in plants as a food, in anticipation of future usefulness in the formation of plant tissues.

Description of the Starch Granule.-In young plants the starch granule is always spherical, but it subsequently becomes ovoid, lenticular, polyhedral, or irregular in shape. Various plants exhibit characteristic starch granules peculiar to each, which may be identified by the microscope. The granule occurs in concentrically arranged layers of different densities, arranged around a central point, usually situated at one end of the granule, and called the hilum.

GLYCERITUM AMYLI, U. S.—Glycerite of Starch. (Starch Jelly.)-10 p. starch; 90 p. glycerin.

CETRARIA, U. S.—Cetraria. (Iceland Moss.)—A lichen found in northern latitudes, on both continents, named cetraria islandica, containing 70 per cent. lichenin, C12H20O10 (strongly allied to starch, which swells up in water); about 3 per cent. cetraric acid, C1HO (crystalline and very bitter); lichenstearic acid, C14H34O3; sugar, oxalic acid, fumaric acid, and cellulin.

DECOCTUM CETRARIÆ, U. S.—Decoction of Cetraria. (See Decocta, Part II.)

In the official process for this preparation, the cetraria is first macerated with water, and expressed before it is finally boiled with water, to separate the bitter principle, cetraric acid.

CHONDRUS, U. S.-Chondrus (Irish Moss.)—An alga growing i the Atlantic Ocean, named Chondrus crispus, containing 70 per cent. carrageenin, a mucilaginous principle, differing from gum by not precipitating with alcohol; from starch, by not becoming blue with iodine; and from pectin, by not precipitating with subacetate of lead.