This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
C17H19No3 + H2O.
10 to 15 per cent. It is present in opium in combination with meconic acid, and the meconate of morphia is separated by repeated macerations with water, after which the salt is decomposed by alcohol and water of ammonia, the latter precipitating the morphine and the former taking up the coloring matter as soon as it is freed from the alkali. The crystals of morphine are then boiled in alcohol and the solution filtered through animal charcoal. Morphine is in the form of white, or colorless crystals, which are inflammable and freely soluble in boiling alcohol, scarcely soluble in cold water, and somewhat so in boiling water. The salts of morphine, however, are freely soluble in water. It is without odor, and has a very bitter taste. Morphine differs somewhat in its mode of action from opium, which may arise from the peculiar state of combination in which it exists in opium. Morphine is more insoluble than its salts, and for this reason the latter are preferred for administration.
Morphine is more powerful than opium ; but it causes less vascular and arterial excitement, less headache and vertigo, less subsequent depression, less constipation, and often it will be retained on an irritable stomach, when opium or its tincture (laudanum) would be rejected.
Morphine is indicated when the object is to relieve nervous irritability and induce tranquillity. The effects of morphine differ according to the peculiarities of nervous constitution. The hypnotic effect may be produced and the stimulant action be confined to the heart; in some cases the excitant effect prevails, or the two effects may be equal. The excitant effect may counteract the hypnotic effect to a greater or less degree, resulting in insomnia with restlessness, or even delirium. Females appear to be more liable to its excitant effects than males; and if there is present a highly emotional, excitable and energetic temperament, it causes great distress and dangerous effects when hypodermically administered.
Morphine, in the form of salts, is employed as an anodyne and hypnotic in neuralgic affections, diseases of the heart, painful uterine affections, and in all cases of painful affections. (See Opium.)
The principal salts of morphine are the acetate, the hydro-chlorate and the sulphate.