As already mentioned, magnesia carbonate forms nearly insoluble compounds with arsenic and cobalt, and besides being used as an antidote to those poisons, it has been given with more or less success in cases of poisoning by corrosive sublimate, mercurial oxide, and salts of copper. It is perhaps best suited to neutralize the action of the strong acids, whether mineral or vegetable, and acts well when mixed with charcoal. When used for oxalic acid poisoning, large quantities must be given to form a basic insoluble salt (Husemann).

Preparations And Dose

Magnesia - magnesia levis: dose, as an antacid, 10 to 20 gr.; as a purgative or adjunct, 20 to 60 gr. or more- 4 to 8 gr. will purge an infant at the breast; children of about ten years require 30 to 40 gr. The pulvis rhei compositus (Gregory's powder) contains 6 parts with every 2 of rhurbarb and 1 of ginger. Magnesias car-bonas - magnesioe carbonas levis: dose, 10 to 60 gr.; 10 to 20 gr. as antacid, 20 to 60 gr. or more as a purgative. Liquor magnesias carbonatis should contain nearly 13 gr. in the ounce, but does not well retain this amount. The solutions of Henry, of Dinneford, and of Murray are original preparations of the same active ingredient (about 10 gr. to the ounce), and a convenient "double strength" preparation has been introduced by Kinmond. The bismuth lozenges B. P. contain about 2 gr. of the carbonate of magnesia. Liquor magnesias citratis, the "limonade purgative" of the French codex, may be taken in doses of 5 to 10 fl. oz. A "granular effervescent citrate of magnesia" is in popular demand, but was proved at a trial under the Adulteration Act a few years ago to be in reality a citro-tartrate of soda (Pharmaceutical Journal, 1873). I believe that an article containing at least some citrate of magnesia is now supplied. Magnesilyne is another form of the same remedy. Rochelle salt has also been found as an adulteration of it (Pharmaceutical Journal, February, 1873). In consequence of the high price of citric acid, a formula for producing a meta-tartrate of magnesia has been published (Bulletin, i., 1873). In the same journal, M. Martin records the rather important observation that even carefully prepared citrate, which is perfectly soluble when fresh, is apt to change with age into a subsalt, and to become insoluble. A "boro-citrate," made by dissolving a borate of magnesia in citric acid, has been recommended by Kohler for acid urinary deposits (Medical Times, ii., 1879). Magnesioe sulphas: dose, 10 to 20 gr. for irritable conditions of the stomach, or in combination with astringents or tonics; when given with senna or other purgatives 30 to 60 or 120 gr., according to the frequency of repetition. For diuretic effects 20 to 60 gr., as a purgative in a single dose 2 dr. to 1/2 oz., according to the habit of the patient. Coffee and infusions containing tannin disguise the nauseous taste. Enema magnesioe sulphatis (contains 1 oz. of the salt with 1 of olive oil, and 15 of mucilage starch). The mist. sennoe com-posita contains somewhat more than a drachm in each fluid ounce combined with senna and aromatics.

[Preparations,U. S. P. - Magnesia; Trochisci magnesioe: magnesia 3 troyounces, nutmeg 60 gr., sugar 9 troyounces, mucilage of tragacanth sufficient; make 480 troches; Magnesii carbonas; Liquor magnesii cit-ratis; Magnesii sulphas.]

MANGANESIUM - MANGANESE, Mn, = 55.

Manganese is found in many ores, and generally associated with iron; the most common one is the black oxide, or per-oxide (pyrolusite), which is found abundantly in Great Britain and in various parts of Europe.

Characters

Manganese is a grayish-white metal, hard and brittle, of sp. gr. 8. It emits a peculiar odor in a moist atmosphere, or if handled. When pure it oxidizes readily in the air, and hence is kept under naphtha, or in sealed glass tubes; it is dissolved by dilute sulphuric acid.