Source. - Made by (1) precipitating and rejecting the meconic acid and resins, by adding a solution of chloride of calcium to a concentrated cold watery infusion of opium; (2) evaporating the solution (containing hydro-chlorates of the alkaloids), pressing to remove colouring matter, exhausting with boiling water, filtering, and pressing again; (3) repeating process (2) until solution is nearly colourless; (4) completing decolorisation by digesting with charcoal and filtering; (5) precipitating morphia by ammonia, washing, diffusing in water, dissolving in hydrochloric acid and crystallising out.

Characters. - White acicular prisms of silky lustre; soluble in water and in spirit.

Incompatibles. - The alkaline carbonates, lime-water, salts of lead, iron, copper, mercury, and zinc, liquor arsenicalis, and all astringent vegetables. Dose. - 1/16 to 1/4 gr.

a. Liquor Morphise Hydrochloratis. - Solution of Hydrochlorate of Morphia. 4 gr. in 1 fl.oz. of a mixture of Spirit, Water, and Diluted Hydrochloric Acid. Dose, 10 to 60 min.

b. Suppositoria Morphiae, - 1/2 gr. in each.

c. Suppositoria Morphias cum Sapone. - 1/2 gr. in each.

d. Trochisci Morphiae. - 1/38 gr. in each.

e. Trochisci Morphiae et Ipecacuanhas. - 1/36 gr. with 1/12 gr.

Ipecacuanha in each.

From Morphia Hydrochloras is made:

Morphiae Acetas. - Acetate of Morphia. C17Hl9NO3. C2.H4O2.

Source. - Made by precipitating morphia from a solution of the hydrochlorate by means of ammonia, dis-solving in acetic acid and water, and evaporating.

Characters. - A white powder, soluble in water and in spirit.

Dose. - 1/8 to 1/2 gr.

a. Injectio Morphias Hypodermica. - Hypodermic Injection of Morphia. 1 gr. acetate in 12 min.. made by freshly pre-paring the acetate as above, but without evaporating. Dose, hypodermically, 1 to 6 min.

β. Liquor Morphias Acetatis - Solution of Acetate of Morphia. 4 gr. in 1 fl.oz. of Spirit. Water, and Diluted Acetic Acid. Dose, 10 to 60 nun.

Action And Uses. 1. Immediate Local Action And Uses

Externally. - Opium is very generally believed to be anaesthetic and anodyne when applied to the unbroken skin, and the emplastrum, linimentum, fomentations, and other pre-parations are used to relieve the pains of neuralgia, lumbago, abscess, etc. It is doubtful, however, whether morphia can bo absorbed by the unbroken skin, and the benefit derived from these applications may be referable to the spirit, resins, and heat. Wounds, ulcers, and exposed mucous surfaces readily absorb opium, which is used in painful ulcers, conjunctivitis, and similar diseases. It is occasionally given by the endermic method, especially in the epigastric region. Hypodermic in-jection is a most valuable means of administering morphia, when a specially rapid or local effect is desired, or when the stomach is irritable or inaccessible.

Internally. - Opium has a peculiar taste, is quickly ab-sorbed by the mucous membrane, and exerts an action upon the mouth, which, although in part specific and in part remote, is chiefly an immediate local one. A full medicinal dose renders the mouth dry and the tongue foul, from diminution of the secretions, with thickness of the voice and some thirst. On entering the stomach opium may cause sickness, from brief irritation of the nerves, but sensibility is quickly reduced, hunger and pain relieved or removed; appetite, gastric secretion, and digestive activity diminished; and the afferent impressions which give rise to vomiting arrested, so that direct emetics will no longer act. Anorexia, nausea, and sickness may occur as sequelae of the same or larger doses.

These effects of opium on the stomach have a double bearing in therapeutics. First, they indicate that it has a constant tendency to derange digestion. Secondly, it is a powerful means of relieving gastric pain and vomiting, whatever their cause, but especially in the acute catarrh which remains as the effect of irritant food, alcohol, or poison, after these have been removed; in ulcer, "chronic," or malignant; and in reflex sickness, due to disease, irritation, or operation, in some other part of the abdomen. In chronic dyspeptic pain it is manifestly contra-indicated.

The action of opium on the intestine is distinctly sedative, although very brief primary stimulation may sometimes be recognised. Both the sensible and insensible impressions from the mucous membrane are diminished or arrested by medicinal doses. Pain is prevented or relieved, the secretions are less abundant, and peristalsis is more feeble or arrested; the total result being anodyne and astringent. Opium is therefore a most valuable remedy for unnatural frequency of the bowels, as in simple diarrhoea, dysentery, the first stage of cholera, the ulceration of typhoid fever and tuberculosis, and irritant poisoning. In all such cases, however, it must be employed with the cautions to be afterwards insisted on, and in most instances it is best prescribed as an addition to other astringents such as chalk, lead, and tannic acid in its many forms; the amount of opium being a minimum, but still sufficient to assist the less powerful drugs. It has the further advantage of relieving abdominal pain. Even infants (see cautions, page 197) may thus be treated for diarrhoea with the greatest benefit.

Opium is of still greater service in paralysing the bowels in hernia, intestinal obstruction, peritonitis, and visceral perforations, ruptures, and wounds. The drug must be freely and continuously given in such cases, until nature or art can afford relief.

Given by the rectum, as the enema or suppository, opium relieves local pain, diairrhoea, dysentery, and spasm of the rectum or neighbouring parts, sets the pelvic organs at rest after operations, and prevents irritability of the rectum by nutrient enemata. The dose of opium by the rectum should be half as much more as by the mouth. A trace of morphia is excreted unabsorbed in the faeces.