This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Take two ounces of pearl barley and wash well with cold water, rejecting the washings. Afterwards boil with a pint and a half of water for twenty minutes in a covered vessel, and strain. The product may be sweetened and flavoured with lemon peel, or lemon peel may be introduced while boiling is carried on. Lemon juice is also sometimes added to flavour. A bland, demulcent, and mildly nutritive beverage.
Wash two ounces of pearl barley with cold water. Then boil it for five minutes in some fresh water, and throw both waters away. Then pour on two quarts of boiling water, and boil it down to a quart. (Stir and skim occasionally.) Flavour with thinly cut lemon rind; add sugar to taste, but do not strain unless at the patient's request.
To a tablespoonful of pearl barley washed in cold water add two or three lumps of sugar, the rind of one lemon, and the juice of half a lemon. On these pour a quart of boiling water, and let the mixture stand for seven or eight hours. Strain. The barley water should never be used a second time. Half an ounce of isinglass may be boiled in the water. If not needed at once, these barley preparations should be kept in the refrigerator and warmed when required.
Thoroughly wash one ounce of rice with cold water. Then macerate for three hours in a quart of water kept at a tepid heat, and afterwards boil slowly for an hour, and strain. A useful drink in dysentery, diarrhoea, and irritable states of the alimentary canal. It may be sweetened and flavoured in the same way as barley water.
Take a pinch of isinglass, and boil it in half a pint of new milk with half a dozen bruised sweet almonds and three lumps of sugar.
Whole linseed, white sugar, each one ounce; licorice root, one half ounce; lemon juice, two ounces. Mix. An agreeable demulcent.
One half cupful of flaxseed to one quart of boiling water; boil thirty minutes and let stand a little while near the fire to thicken more. Strain, and add lemon juice and sugar.
Red or black currant jelly, dissolved in hot or cold water or strained tamarind tea, make excellent invalid beverages.