Carbonate of Magnesia 3 (MgO, Co2, +HO) + MgO, 2 HO. MagnesiAe Carbonas Pondero-sum (Ph. Dub.). Sub-carbonate or Hydrated Carbonate of Magnesia. A mixture of Carbonate and Hydrate of Magnesia.

MagnesAe Carbonas Levis. Light Carbonate of Magnesia. Identical in chemical composition with the Carbonate of Magnesia.

Med. Prop. and Action. Purgative, in doses of gr. xx. - gr. lx.; antacid from gr. v. - gr. xx. It is particularly adapted as a purgative for children, in doses of gr. ij. - v., and may be given in Aq. Anethi, or combined with Rhubarb. Milk is also a good vehicle for it. Its purgative action is supposed, in a great measure, to arise from the Magnesia combining with the acids of the alimentary canal, forming with them soluble compounds; "For," observes Dr. A-T. Thompson,* "if no acid be present, Magnesia does not appear to increase in any degree the peristaltic motion of the bowels." If given in large and continuous doses, it may prove hurtful by accumulating in the intestines. Sir B. Brodiet mentions a case in which, after death, many pounds of Magnesia were found collected in the colon, above a contracted part of the rectum.

Dose of the Carbonate or Light Carbonate, gr. v. - gr. xx., as an antacid; as an aperient, gr. xx. - gr. lx.

Incompatible*, the same as Magnesia Usta; also Lime Water.

1756. Therapeutic Uses

In Acidity of the Prima Via, gr. xx. of MagnesiAe Carb. in some aromatic water or milk, proves eminently serviceable. In Sympathetic Vo?niting, particularly in that of Pregnancy, attended with acidity, it also occasionally affords complete relief; and in Cardialgia arising from the same cause, Dr. Symonds states that he has found it successful when a great variety of other means had been unavailing. It is best taken immediately after a meal. In Pyrosis, it is occasionally effectual.

1757. In The Diarrha Of Children, It Proves Valuable As An Antacid And Absorbent

It is best combined with a few grains of Rhubarb and an aromatic. In Aphtha and Aphthous Ulceration, it may also be given with advantage.

1758. In Calculous Diseases, when lithic or uric deposits in the urine indicate the exhibition of alkalies, Sir B. Brodie§; prefers the use of Magnesia to other remedies of the same class. He considers that it does not possess the same attenuating action on the fluids of the body, as that which is rendered soluble, by its combination with the acid in the stomach, can alone enter into the circulation. He advises the following formula, which is generally found to agree well with the stomach, and to produce a very immediate effect on the urine: - ft Magnesias Carb. gr. vj., Potass. Bicarb. gr. xij., PotassAe Tart. gr. xv., M. ft. pulv. ves-pere sumend.

* Dispensatory, p. 1076.

Dis. of the Urinary Organs, p. 204.

Lib. of Med., vol. iv. p. 79. § Op. cit.

1759. In Gout, antacids are often of remarkable service in correcting the morbid state of the urine. " Magnesia, both Calcined and Carbonated," observes Dr. Copland,* "has been generally employed, and is preferable, on the whole, to any other absorbent, inasmuch as it acts gently upon the bowels and kidneys without weakening the digestive mucous surface. Its effects are often very remarkable."

1760. In the Flatulence of Childhood, a few grains of Magnesia in any aromatic water, particularly in Aq. Anethi, are generally very effectual.

1761. In Poisoning by Oxalic and the strong Mineral Acids, it is a valuable antidote, but not superior to Chalk.

1762. In Diabetes, Dr

Willis speaks in the highest terms of the value of Magnesia. In addition to his own testimony, he adduces that of Hufeland, who speaks favourably of it, and mentions two cases treated by Mr. B. Phillips, in which, under the use of this remedy, the sugar disappeared from the urine, and the thirst and all the other symptoms of the disease were immediately relieved. Subsequent experience has shown, that though occasionally useful as a palliative, it is of no value as a curative agent.

1763. In Herpes Zoster, To Relieve The Deep-Seated Pain In The Chest, Dr

A. T. Thompson advises the following formula: - ℞Magnes. Carb. j., Vin. Colchici, T. Opii aa f3ss., Mist. Camph. fj., M. ft. haust.