Properties and Uses. - Like amyl nitrite (or any nitrite), except that its action is not quite so prompt, but is more persistent. Angina pectoris, asthma, convulsions, tetanus, collapse, illuminating-gas, strychnine- and chloroform-poisoning, cardiac stimulant. If taken early, often wards off attacks of cardiac pain and epileptic seizures. It is thought that in undergoing alkaline decomposition in the system the nitrite is formed, which yields nascent nitrous acid.

III. Aldehydes.

1. Halogen Derivatives.

Aldehydes are obtained from alcohol by removing 2 atoms of hydrogen, hence name al(cohol) + dehyd (rogenstus) - de, from, + hydrogen - i. e., alcohol deprived of hydrogen. They are chemically between alcohols and acids, and may be considered unsaturated hydrocarbons attached to COH, thus:

The hydrogen may be removed by oxidation, when 1 atom of outside oxygen combines with 2 atoms of alcoholic hydrogen, forming 1 molecule of water and the aldehyde, which by further oxidation forms its corresponding acid.

Liquor Formaldehydi. Solution of Formaldehyde. - (Syn., Liq. Formaldehyd., Formalin, Formal, Formol; Fr. Solute d'Aldehyde de formique; Ger. Formaldehyd solutus, Formaldehydlosung.)

Manvfacture: Pass heated vapors of methyl alcohol mixed with air over glowing coke or copper spirals, or pass methane (marsh gas) over a heated mixture of copper, pumice, and asbestos fibres, and the resulting products of oxidation into water, removing any unde-composed methyl alcohol by subsequent distillation, and adjusting proper strength by dilution or concentration. It is a clear, colorless or nearly colorless aqueous liquid (solution), pungent odor, caustic taste, vapor an irritant to mucous membrane, miscible with water or alcohol, sometimes cloudy on long standing, especially in the cold, from separation of paraformaldehyde; evaporate over sulphuric acid, or in vacuum, have formed rapidly solid paraformaldehyde; heat above 100° C. (212° F.) sublimes; at 153-172° C. (307-342° F.) melts, evolving gaseous formaldehyde; contains 37 p. c. by weight of formaldehyde, CH2O, with varying amounts of methyl alcohol to prevent polymerization. Tests: 1. Dilute 5 Ml. (Cc.) with distilled water 25 Ml. (Cc), + 3 Ml. (Cc.) of silver ammonium nitrate T. S. - metallic silver produced either as finely divided gray precipitate or bright metallic mirror on sides of test-tube. 2. Add 2 drops to 5 Ml. (Cc.) of sulphuric acid containing a little salicylic acid, warm gently - permanent deep red color. Impurities: Free acids, etc. Should be kept dark, moderately warm.

Properties and Uses. - Antiseptic, disinfectant, germicide, irritant, preservative; about equal to corrosive mercuric chloride in power. A room containing 500 cubic feet can be disinfected by 1 pint (.5 L.) when converted into vapor, within an hour, or 2 pints (1 L.) will suffice for an ordinary-sized room. Has been employed largely but unlawfully for preserving milk, food, beer, wine, etc.; used also intravenously for combating septicaemia; diluted with 2-10 parts water claimed to retard growth of uterine cancer.

Veroform Germicide and Veroform Antiseptic are solutions of soap containing formaldehyde gas, the former 20 p. c, the latter 6 p. c, useful in sterilizing hands, etc.

Paraformaldehydum. Paraformaldehyde, (CH2O)3. - (Syn., Para-form, Trioxymethylene, Triformol; Fr. Paraldehyde formique; Ger. Paraformaldehyd.)

Manufacture: This polymeric form of formaldehyde is obtained by evaporating formaldehyde solution (40 p. c. aqueous solution), when a portion of the gas volatilizes and another portion polymerizes and becomes insoluble, separating as white flocculent mass, which upon drying has the composition (CH2O)3. It is in white, friable masses, powder, slight odor of formaldehyde, on heating partly converted into formaldehyde and partly sublimed unchanged; slowly soluble in water, more readily in hot water with the formation of formaldehyde, insoluble in alcohol, ether, soluble in fixed alkali solutions; contains 95 p. c. of (CH2O)3. Tests: 1. Mix .01 Gm. with morphine sulphate .01 Gm. + 10 drops of sulphuric acid - violet-red color, changing to blue. 2. Incinerate 2 Gm. - ash .1 p. c; shake .5 Gm., finely powdered, with 10 Ml. (Cc.) of distilled water - latter remains neutral. Incompatibles: Bases, oxidizing agents, gelatin, tannin, etc. Should be kept cool, dark, in well-closed containers.

Properties and Uses. - Antiseptic (internally and externally), escharotic, disinfectant by heating (preferably compressed tablets); inhalations; warts, etc. Dose, gr. 5-15 (.3-1 Gm.); externally 10 p. c. suspension in collodion.

Hexamethylenamina. Hexamethylenamine, C6H12N4. - (Syn., Hexam., Hexamethylene-tetramine, Urotropinum, Urotropine, Uri-tone, Formin, Aminoform, Cystogen; Br. Hexamina, Hexamine; Ger. Hexamethylentetramin(um). A condensation product of ammonia and formaldehyde.)

Manufacture: Add stronger ammonia water (80), in successive portions, to a 40 p. c. solution of formaldehyde (100), keep well cooled, set aside 12-24 hours to crystallize. It is in colorless, lustrous, odorless crystals, white crystalline powder, soluble in water (1.5), alcohol (12.5), ether (320), chloroform; aqueous solution alkaline; at 263° C. (506° F.) sublimes without melting, but with partial decomposition, emitting disagreeable odor. Tests: 1. Heat aqueous solution (1 in 10) with diluted sulphuric acid - decomposes with liberation of formaldehyde (odor; and darkens silver ammonium nitrate T. S. paper). 2. Heat aqueous solution (1 in 10) with diluted sulphuric acid, supersaturate with sodium hydroxide solution - ammonia evolved; incinerate 2 Gm. - residue .05 p. c. Impurities: Heavy metals, ammonium salts, chloride, sulphate. Should be kept in well-closed containers. Dose, gr. 5-15 (.3-1 Gm.).