This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Malt. (Not official.) Synonym. - Byne. The seed of common barley, Hordeum distichum (nat. ord. Graminaceae), caused to enter the incipient state of germination by artificial means, and dried. It contains the ferment Diastase, which can convert starch into Dextrin and Maltose. Thus io(C6H10O5)+4H2O=4C12H22O11, Maltose +(C12H20O10), Dextrin.
This varies very much. The chief constituent is Maltose (C12H22O11); there is also some Dextrin (C12H20O10), some Diastase (unless destroyed by boiling), Albumin, Inorganic sails contained in barley, and sometimes Alcohol.
Dose, 1 to 4 fl. dr.; 4. to 15. c.c
Maltose is a very valuable food, especially for persons who are suffering from wasting diseases, and have a feeble digestion. It is easily retained by the stomach, even when, as often is the case in phthisis, other food, especially cod-liver oil, is rejected. In such a case a malt extract is an excellent substitute for cod liver oil. Maltose as a food leads to the formation of fat. The diastase contained in the malt extract, acting upon the starch in farinaceous food, converts it into dextrin and maltose, and thus, if the secretion of saliva and pancreatic juice is feeble, the malt extract to some extent supplies their place. Like the ferments in pancreatic juice and saliva, diastase can only act in an alkaline medium, and therefore should not be given until, at least, two hours after a meal. Inasmuch as diastase is a most important constituent, all malts should be rejected which do not contain at least 4 per cent. of diastase. The liquid malts containing alcohol, which destroys this ferment, are worthless for assisting starch digestion and are usually only beers of an inferior quality. Malt extract, to which a suitable amount of fluid extract of rhamus purshiana has been added, is an excellent laxative. Emulsions of cod-liver oil in it are frequently useful. Bynol is an example of these. They should contain 1 part of oil to 4 of malt. A mixture of extract of malt and iron is also valuable (ferric pyrophosphate, 2; water, 3; dissolve and add extract of malt, 95. Dose, 1 to 4 fl. dr. 4. to 15. c.c.).