The centesimal composition of maize is as follows:—Flesh formers (albumenoid bodies), 9·9; heat and fat formers (starch, dextrin, and fat), 71·2, fibre, 4·0; ash, 1·4; water, 13·5.
Letheby says of maize: “The grain is said to cause disease when eaten for a long time, and without other meal—the symptoms being a scaly eruption upon the hands, great prostration of the vital powers, and death after a year or so, with extreme emaciation.
These effects have been frequently observed amongst the peasants of Italy, who use the meal as their chief food, but I am not aware of any such effects having been seen in Ireland, where it is often the only article of diet for months together.”
Millions of bushels are grown every year in the United States of America, and large quantities are continually imported into England, where it is held in high esteem by cattle breeders, it being much cheaper than many of our home-grown productions. It is occasionally given to horses as a substitute for oats.
MALAG′MA. In pharmacy, a poultice or emollient application.
MA′LIC ACID. H3C4H3O5. Syn. Acidum malicum, L. This acid exists in the juice of many fruits and plants, either alone or associated with other acids, or with potassa or lime. In the juice of the garden rhubarb it exists in great abundance, being associated with acid oxalate of potassa.
Prep. (Everitt.) The stalks of common garden rhubarb are peeled, and ground or grated to a pulp, which is subjected to pressure; the juice is heated to the boiling point, neutralised with carbonate of potassa, mixed with acetate of lime, and the insoluble oxalate of lime which falls is removed by filtration; to the clear and nearly colourless liquid, solution of acetate of lead is next added as long as a precipitate (‘malate of lead’) continues to form; this is collected on a filter, washed, diffused through water, and decomposed by sulphuric acid, avoiding excess, the last portion of lead being thrown down by a stream of sulphuretted hydrogen; the filtered liquid is, lastly, carefully evaporated to the consistence of a syrup, and left in a dry atmosphere until it becomes converted into a solid and somewhat crystalline mass of malic acid. If perfectly pure malic acid is required, the malate of lead must be crystallised before decomposing it with sulphuretted hydrogen. Prod. 20,000 gr. of the peeled stalks yield 12,500 gr. of juice, of which one imperial gallon contains 11,1391⁄4 gr. of dry malic acid.
Obs. By a similar process malic acid may be
prepared from the juice of thee berries of the mountain ash (Sorbus aucuparia), just when they commence to ripen, or from the juice of apples, pears, &c.
Prop., &c. Malic acid is slightly deliquescent, very soluble in water, soluble in alcohol, and has a pleasant acidulous taste. The aqueous infusion soon gets mouldy by keeping. When kept fused for some time at a low heat, it is converted into fumaric acid; and when quickly distilled, it yields maleic acid, while fumaric acid is left in the retort. With the bases malic acid forms salts called malates. Of these the acid malate of ammonia is in large, beautiful crystals; malate of lead is insoluble in cold water, but dissolves in warm dilute acid, from which it separates on cooling in brilliant silvery crystals; acid malate of lime also forms very beautiful crystals, freely soluble in water; neutral malate of lime is only sparingly soluble in water; the first is obtained by dissolving the latter in hot dilute nitric acid, and allowing the solution to cool very slowly.