Essence of peppermint (peppermint oil) by means of a little white sugar, readily mixed with water, and, in the proportion of thirty drops to a pint, makes a pleasanter and better simple water than that distilled from the recent herb; which, from not retaining its flavour in perfection long, is seldom to be procured good in the winter season. The spirituous peppermint-water may be made, by employing brandy in lieu of water, which will prove less pernicious to the organs of digestion than that sold under the name of peppermint cordial, made with spirit of wine*. Essence of peppermint is chiefly employed to correct the griping quality of purgatives, and render nauseous medicines more palatable and pleasant to the stomach. It is, however, often taken alone on sugar, or in a little brandy or water, for flatulence, colicky pains in the stomach and intestines, and fits of spasmodic asthma, in which it generally affords speedy but temporary relief.
Medical Guide, 1808