White Decoction.
Take of the purest chalk, in powder, two ounces; gum arabic half an ounce; water, three pints. Boil to one quart, and strain the decoction.
This is a proper drink in acute diseases, attended with, or inclining to, a looseness, and where acidities abound in the stomach or bowels. It is peculiarly proper for children when afflicted with sourness of the stomach, and for persons who are subject to the heartburn. It may be sweetened with sugar, as it is used, and two or three ounces of simple cinnamon-water added to it.
An ounce of powdered chalk, mixed with two pints of water, will occasionally supply the place of this decoction, and also of the chalk julep.
William Buchan
Domestic Medicine 2nd edition 1785