Mustard Whey.
Take milk and water, of each a pint; bruised mustard seed, an ounce and a half. Boil them together till the curd is perfectly separated; afterwards strain the whey through a cloth.
This is the most elegant, and by no means the least efficacious method of exhibiting mustard. It warms and invigorates the habit, and promotes the different secretions. Hence, in the low state of nervous fevers, it will often supply the place of wine. It is also of use in the chronic rheumatism, palsy, dropsy, &c. The addition of a little sugar will render it more agreeable.
The dose is an ordinary tea-cupful four or five times a-day.
William Buchan
Domestic Medicine 2nd edition 1785