(Open-chain Compounds.)

I. Hydrocarbons. Pental. Pentalum. - Tri-methyl-ethylene, Iso-amylene.

Manufacture: This is from the fifth member of the series, amylene. The amyl hydride (hydroxide) or amylic alcohol is digested with zinc chloride for 24 hours, or preferably the two are shaken occasionally together for some time with diluted sulphuric acid, thereby producing amyl sulphuric acid, which when diluted with water yields tertiary amyl alcohol and pure pental, the latter being separated by fractional distillation. It is a colorless. liquid, very inflammable and volatile, not affected by light or air, insoluble in water, miscible in all proportions with alcohol, chloroform, and ether, sp. gr. 0.620, boils at 38° C. (100.4° F.).

Properties and Uses. - Anaesthetic; when inhaled acts as rapidly and safely as nitrous oxide gas, and superior to it in having a longer action and no unpleasant after-effect; acts more promptly than chloroform (1-3 minutes). Consciousness is not lost when the stage of pain-insensibility is reached; stage of exhilaration is seldom present; and drug does not lose effect by repetition; used for minor surgical operations, tooth-extraction, etc., being administered like chloroform. Dose, ev-10 (.3-6 Ml. (Cc.)) internally, but for inhalation 3ij - 4 (8-15 Ml. (Cc.)).

1. Halogen Derivatives. Methyl Chloride. Mono-chlor-methane.

Manufacture: Methyl alcohol, hydrochloric acid (gas), and zinc chloride are heated together under pressure in a steam digester - CH3OH + HC1=CH3C1 + H2O; the zinc chloride simply facilitates the process; the methyl chloride has now to be purified by washing with water, acid, and alkali. It is a colorless gas, burning with a green flame, having an ether and chloroform-like odor, 1 vol. water dissolves 4 vols., while 1 vol. methyl or ethyl alcohol dissolves 35 vols.; it is also freely soluble in ether and chloroform. When cooled to - 23° C. (- 11.4° F.), under normal pressure, becomes a liquid which boils at - 21° C. (- 5.8° F.); a pressure of 5 atmospheres at normal temperature also condenses it.

Properties and Uses. - Local anaesthetic. It is kept usually in pointed glass pearls; the point being broken off, the heat of the hand is sufficient to volatilize the contents, and thus force it out as a fine spray upon the desired location. Before applying, it is well to wash the skin with soap and water to remove all fat, and to hold spray-nozzle 10 inches from the spot to be frozen. The skin soon becomes white and parchment-like, when minor surgical operations, as opening abscesses, boils, etc., may be performed painlessly. The spray should not be continued longer than 2-4 minutes, as death of tissue may result.

Methylene Bichloride. Di-chlor-methane.

Manufacture: Pass chlorine into methyl chloride (CH3C1), or reduce chloroform (CHC13) with zinc and hydrochloric acid. It is a colorless liquid, chloroform-like odor, insoluble in water, soluble in alcohol or ether, sp. gr. 1.354, boils at 40° C. (104° F.). It should be kept in well-stoppered bottles, in the dark, to prevent decomposition, which may also be obviated by the addition of 1 p. c. alcohol. Dose, ex-30 (.6-2 Ml. (Cc.)), but mostly inhaled.

Properties and Uses. - Anaesthetic; for minor operations use 3j-2 (4-8 Ml. (Cc.)), for major ones, should not employ more than 3iij-6 (12-24 Ml. (Cc.)).

Methylthionine Chloride. Methylthioninae Chloridum, C16H18N3SCl. - (Official.) See page 826.

Methyl Tri-chloride. Chloroformum. Chloroform. - Tri-chlor-methane, CHCl3. - (Official.) See page 826.

Methyl Tri-bromide. Bromoformum. Bromoform. - Tri-brom-methane, CHBr3. - (Official.) See page 829.

Methyl Tri-iodide. Iodoformum. Iodoform. - Tri-iodo-methane, CHI3. - (Official.) See page 830.

Ethyl Chloride, AEthylis Chloridum. Mono-chlor-ethane, C2H5C1. - (Official.) See page 832.

Ethylene Bichloride. AEthyleni Bichloridum. - Ethene Chloride, Dutch Liquid.

Manufacture: Combine equal volumes of the unsaturated hydrocarbon ethylene (C2H4) and chlorine (Cl2). It is a colorless, thin, oily, volatile liquid, sweet taste, chloroform-like odor, sp. gr. 1.26, boils at 85° C. (185° F.), soluble in alcohol, ether, sparingly in water.

Properties and Uses. - Anaesthetic. Much safer than chloroform (no collapse), also more pleasant and rapid in action, causes no excitement like ether, and recovery is more rapid. It is, however, more expensive than chloroform, and irritates the throat so much that it is used with difficulty; efficacious locally in neuralgia.

Ethylidene Chloride. Di-chlor-ethane. - Mono-chlorinated Hydrochloric Ether.

This is isomeric with ethylene bichloride, which it resembles in odor; has a density of 1.198, boils at 57.5° C. (135.5° F.), and is. decomposed by sulphuric acid; it is a colorless, hot, sweet, volatile liquid of chloroformic odor.

Properties and Uses. - Anaesthetic for inhalation. Acts similarly to chloroform, but is possibly a better preparation.

Ethyl Bromide. AEthylis Bromidum. - Mono-bromo-ethane, Ether Bromatus, Hydrobromic Ether.

Manufacture: Distil alcohol (12) and sulphuric acid (7), gradually adding potassium bromide (12):