Acid Elixir of Vitriol.
Take of the aromatic tincture, one pint; oil of vitriol, three ounces. Mix them gradually, and after the faeces have subsided, filter the elixir through paper, in a glass funnel.
This is one of the best medicines which I know for hysteric and hypochondriac patients, afflicted with flatulencies arising from relaxation or debility of the stomach and intestines. It will succeed where the most celebrated stomachic bitters have no effect. The dose is from ten to forty drops, in a glass of wine or water, or a cup of any bitter infusion, twice or thrice a-day. It should be taken when the stomach is most empty.
William Buchan
Domestic Medicine 2nd edition 1785