manufacture, acquire a reddish tint on standing, and the origin of this disagreeable phenomenon is still a matter of question. Some claim that the nitrogen of the air acts on the phenol, forming one of the numerous dye-stuffs obtained from benzene. Others think it due to organic impurities, but Schneider furnishes strong proof that copper contamination is the cause. The removal of this color is a matter of considerable difficulty; the only perfect way is by the redistillation of the carbolic acid, an operation that is not safe for an ordinary pharmacist.

It must be borne in mind that the vapors of carbolic acid are inflammable, and, therefore, great care should be used in melting same by means of heat; in fact, the best way to melt the substance is to dip the bottle in heated water rather than to heat the mass direct, even on a water-bath.

Carbolic acid has a number of characteristic reactions, among which may be cited the violet-blue color it gives with a drop of ferric chloride solution, its coagulating action on albumin and collodion, and the yellow precipitate with bromine. The first two tests are of interest as distinguishing between itself and creosote, carbolic acid being a frequent substitute for the more costly wood-tar products. The bromine reaction is of interest as the basis of the volumetric estimate of carbolic acid (see Part V).

As mentioned above, carbolic acid can be liquefied by addition of 8 per cent. of water. This solution, however, is scarcely as desirable as one liquefied by an addition of a small quantity of alcohol although even that may be objectionable on account of possible irritating qualities of the alcohol. This solution, the so-called 95 per cent. carbolic acid, is what is generally dispensed in answer to calls for pure carbolic acid instead of the crystals themselves. The extended use of this 95 per cent. carbolic acid by suicides, and the almost invariable fatal results from use in this way, render it necessary for pharmacists to use great caution in selling same. In the city of Cleveland the pharmacists have attempted to introduce for general dispensing purposes a 33 per cent. carbolic acid, made by mixing the crystals with a sufficient quantity of glycerin. This solution serves all the legitimate purposes of carbolic acid, is freely miscible with water in all proportions, and is of sufficient strength for any real needs for this antiseptic; while, on the other hand, if the would-be suicide administers same, corrosive action is scarcely likely to occur, and this is usually the cause of death. Such carbolic acid is sold in Cleveland under the name of "carbolic acid No. 33."

Carbolic acid is one of the most valuable of all antiseptics, its germicidal action being due to the fact that it coagulates albumin. In full strength it is, as mentioned above, a very caustic poison, the antidote for which is sodium sulphate, followed by mucilaginous drinks. Recent investigation shows that oil should never be used for an antidote for carbolic acid, for while oil lessens the caustic effect by dissolving the carbolic acid, it then brings it to a form best adapted to assimilation by the system; in other words, while being an antidote for the caustic effect of the poison, it opens the way for it to exert its physiologic influence.

Sodium sulphate is suggested as an antidote because it forms

with carbolic acid the harmless sodium sulphocarbolate, and this being produced, the escharotic action of the acid is relieved by mucilaginous liquids, such as mucilage of flax-seed. Alcohol has also been suggested as an antidote for carbolic acid. The official preparations of carbolic acid are a 5 per cent. ointment and the glycerite, which contains 20 per cent. of the phenol. In some sections carbolic oil, made by combining phenol with either olive oil or cotton seed oil, in proportions from one to eight, is a favorite remedy for cuts and sores. Dose.-65 milligrammes (1 grain).

PHENOL LIQUEFACTUM. Liquefied Phenol.

A liquid composed of not less than 86.4 per cent., by weight, of absolute Phenol [C2H2OH=93.34] and about 13.6 per cent., by weight, of water.

Recipe.-Phenol, a convenient quantity.

Distilled Water, a sufficient quantity.

Liquefy the Phenol by placing the unstoppered container in a water-bath, and apply heat gradually until the crystals have melted; transfer the liquid to a tared vessel and weigh; then add for each nine grammes of Phenol one gramme of Distilled Water and mix thoroughly. It should be kept in dark amber-colored, well-stoppered bottles.

A colorless liquid, which may develop a slight reddish tint upon keeping, having a characteristic, somewhat aromatic odor, and when copiously diluted with water, a sweetish taste with a slightly burning after-taste, and, when undiluted, cauterizing and whitening the skin and mucous membrane.

Specific gravity: about 1.065 at 25° C. (77° F.).

Soluble in 12 parts of water at 25° C. (77° F.). Miscible with alcohol, ether, and glycerin in all proportions.

One part of Liquefied Phenol acquires a permanent cloudiness when mixed respectively with 2 parts of chloroform, 1.5 parts of benzene, 2.5 parts of carbon disulphide, 2 parts of turpentine, or 2.5 parts of olive oil.

Liquefied Phenol begins to crystallize when the temperature of the liquid is lowered to about 13.5° C. (56.3° F.).

When heated, Liquefied Phenol begins to boil at about 115° C. (239° F.), and upon continuing the heat the boiling-point rises; it should not exceed 188° C. (370.4° F.). When thus deprived of water, it should respond to the tests given under Phenol.

Remarks. As mentioned under Phenol, that chemical forms a permanent liquid by the addition of from 8 to 10 per cent. water, and this liquid has been given pharmacopoeial recognition. Its use is, of course, the same as phenol.

Dose.-0.05 Cc. (1 minim).

Acidum Carbolicum Crudum (U. S. P. 1890).-Crude carbolic acid is a liquid consisting of various constituents of coal-tar obtained by fractional distillation. The official crude carbolic acid is a nearly colorless or reddish or brownish-red liquid, and possesses a characteristic odor. The true carbolic acid ordinarily sold in stores represents a very dirty black liquid, which has but little value, as it is notoriously weakened by addition of water. Crude carbolic acid is used entirely as a disinfectant, for which purpose it is better than the crystals, because it contains a large quantity of cresol in addition to its chief constituent, phenol.

Anisol, CHOCH,, as mentioned above, is phenylmethyl-ether. We have already learned that if methyl alcohol and ethyl alcohol are combined in the presence of sulphuric acid, there will be yielded methyl-ethyl-ether, and in the same way if methyl alcohol and phenol are mixed in the presence of sulphuric acid, methylphenylether, or anisol, is produced. As its name suggests, it is the chief constituent of oil of anise.

As the consideration of methyl salicylate was deferred until we had discussed

salicylic acid, it is consistent to refer the official phenyl salicylate, or salol, to the same heading.

Picric acid, C,H,(NO,),OH, is a trinitrophenol; that is, it is phenol in which three of the hydrogen atoms of the benzene nucleus are replaced by NO, groups, these groups replacing the hydrogen attached to carbon atoms one, two, and four respectively.

At this place it might be stated that, for purposes of convenience, chemists have numbered the carbon atoms of the benzene ring as shown below:

Picric acid is made by treating trinitrobenzene with potassium ferricyanide. It appears in bright yellow crystals, soluble in water, having a strong acid character, and very explosive, hence should be handled by the pharmacist with the utmost It is not used much in pharmacy, its chief value being as a dye for silk; in certain countries it is used as an explosive, and in chemistry it is used as a reagent for alkaloids, and also for albumin and sugar in urinalysis.

care.

Sulphocarbolic acid (or phenol sulphonic acid) is a body prepared by treating carbolic acid with sulphuric acid. Its composition is best understood from the graphic formula:

The official sodium salt of this acid is made by treating mixture of sulphuric acid and carbolic acid with barium carbonate, whereby solution of barium sulphocarbolate is produced, and this solution, on being treated with a molecular quantity of sodium carbonate, produces sodium sulphocarbolate, while the barium is precipitated as barium carbonate. (See Sodium Compounds, p. 469.)

Soziodol represents sulphocarbolic acid in which two of the hydrogen atoms of the benzene nucleus have been replaced by iodine, and, indeed, those hydrogens attached to the carbon atoms numbers two and six.

This is used as an antiseptic in the form of ammonium, barium, lead, and other metallic salts.

Sozol is a trade name for aluminum sulphocarbolate.

Aseptol is an aqueous solution of orthosulphocarbolic acid, This body differs from sulphocarbolic acid, mentioned above, in having the hydroxyl and sulphonic acid (SO,H) groups on adjoining carbon atoms, this distinction between ortho-, meta-, and para-compounds being reserved for discussion later.

DIATOMIC PHENOLS

As we already learned when considering the fatty series, besides alcohols containing one hydroxyl, similar bodies have been found containing two, three, and even more hydroxyls, these being examples of polyatomic alcohols. Thus, glycerin, which, it will be recalled, has

the formula C,H,(OH),, is a polyatomic alcohol. In the same way we can have polyatomic phenols.

The simplest of these phenols are the diatomic-those possessing two hydroxyl groups. The direct benzene derivatives of this class have the formula CH,(OH)2, and with this, as with all di-derivatives of benzene, we have three types, based on the relative positions of the two substituted radicles. Taking C,H,(OH), as example, we can best explain the three modifications by the graphic formulas given below:

It will be seen that the ortho-body is one in which the two hydroxyl groups are on adjoining carbon atoms; the meta- is the one in which one carbon atom intervenes between the two hydroxyl groups on one side, and three on the other, whereas the para-compounds have two carbon atoms intervening between the hydroxyl groups.

Possibly a clearer explanation of this is by numbering the carbon atoms as above, and saying that in the ortho-body the hydroxyl groups are attached to carbon atoms number one and two; in the meta-, the hydroxyl groups are attached to carbon atoms number one and three; and in the para-bodies, the hydroxyl groups are attached to carbon atoms number one and four.

It is hardly necessary to note that this numbering is purely arbitrary, and that a benzene in which two radicles are attached to carbon atoms four and five would be as much ortho- as is that attached to one and two as given above.

Of the three diatomic phenols having the formula C.H(OH)2, the ortho-compound is called pyrocatechin; the meta-, resorcin, and the para-, hydroquinone.

Pyrocatechin, obtained by destructive distillation of catechin, is a constituent of catechu, U. S. P. 1890. It is of no pharmaceutic value. The methyl ether of same, however, is guaiacol.

GUAIACOL. Guaiacol.

C,H,O2 = 123.13

One of the chief constituents [C,H,(OH)(OCH,) 1:2] of creosote, the product from beechwood tar, obtained by collecting and purifying the fraction of creosote boiling between 200° and 205° C. (392° and 401° F.); or prepared synthetically from either catechol by methylating, or from ortho-anisidin by diazotizing and boiling. Guaiacol should be preserved in amber-colored bottles, protected from light. A colorless, crystalline solid, melting at 28.5° C. (83.3° F.), or a colorless, refractive liquid, boiling at 205° C. (401° F.), having an agreeable aromatic odor. Specific gravity of liquid: 1.140 at 25° C. (77° F.).

Soluble in 53 parts of water at 25° C. (77° F.) and in alcohol and ether in all proportions; soluble in acetic acid and in 1 part of glycerin.

The addition of ferric chloride T.S. to an alcoholic solution of Guaiacol (1 in 100) causes an immediate blue color, changing to emerald-green, and finally becoming yellowish.

If 2 Cc. of Guaiacol be shaken with 4 Cc. of petroleum benzin, the mixture should separate, on standing, into two distinct layers. Turbidity or failure to separate into layers indicates the presence of impurities.

One Cc. of Guaiacol should dissolve in 2 Cc. of sodium hydroxide T.S., when heated, and, on cooling, the mixture should congeal to a white mass. Coloration or failure to congeal indicates the presence of impurities. The white mass thus obtained should form a clear solution with 20 volumes of water (turbidity indicates oily hydrocarbons).

One Cc. of Guaiacol, when added to 10 Cc. of concentrated sulphuric acid, should develop a pure yellowish color in the liquid (a reddish color indicating creosote).

Tests for Identity.-Given above.

Impurities.—Oily hydrocarbons and creosote. Details above. This substance can be made synthetically by cooking pyrocatechin with a mixture of potassa and potassium methyl sulphate, although it is usually prepared commercially by the rectification of creosote.

Guaiacol is one of our most valuable internal antiseptics, and for this purpose is used both in tuberculosis and also in intestinal troubles. Dose.-0.5 Cc. (8 minims).

GUAIACOLIS CARBONAS. Guaiacol Carbonate.

(C,H,O),CO,

=

272.05

A guaiacol derivative [(C,H,(OCH,)O),.CO], obtained by the action of carbonyl chloride upon sodium guaiacolate.

White, crystalline powder, of neutral reaction, almost tasteless and odorless. Insoluble in water; soluble in 48 parts of alcohol, 1.5 parts of chloroform, and 13 parts of ether at 25° C. (77° F.); readily soluble in hot alcohol and benzene; slightly soluble in glycerin and fatty oils.

When heated between 84° and 87° C. (183.2° and 188.6° F.) it fuses.

Guaiacol Carbonate is at once decomposed when treated with alcoholic potassium hydroxide T.S., and from the solution so obtained guaiacol may be separated on the addition of an acid.

An alcoholic solution of Guaiacol Carbonate should not yield a bluish-green color on the addition of ferric chloride T.S. (absence of free guaiacol).

Tests for Identity.-Given above.

Impurities. Free guaiacol. Details above.

Remarks. This solid derivative of guaiacol is known as duotal. Its use is similar to guaiacol, over which it possesses the advantage of being less irritating.

Dose.-1 Gm. (15 grains).

LOCH, is the benzoic acid ester of guaiacol, and is used

Benzozol, CHOCOCH,

A diatomic phenol [metadihydroxybenzene, C,H,(OH), 1:3], obtained usually by the reaction of fused sodium hydroxide upon sodium metabenzenedisulphonate. Resorcinol should be kept in dark amber-colored vials.