This section is from the book "The Complete Cook", by J. M. Sanderson. Also available from Amazon: The Complete Cook.
Wash in cold water four ounces of Scotch barley, and put into five quarts of water, with four ounces of sliced onions; boil gently one hour, and pour it into a pan; then put into a saucepan from one to two ounces of fresh beef or mutton dripping. Dripping for this purpose should be taken out of the pan as fast as it drips from the meat; if suffered to remain in the pan it is apt to become rancid. If no dripping is at hand, melted suet will do, or two or three ounces of fat bacon minced fine. When melted in the saucepan, stir into it four ounces of oatmeal, and rub them together until they become a soft paste. Then add, by degrees, a spoonful at a time, the barley broth, stirring it well together till it boils. For seasoning, put in a tea-cup or basin a drachm of celery or cress seed, or half a drachm of each, and a quarter of a drachm of cayenne, finely powdered, or a drachm and a half of black pepper finely powdered, or half allspice; mix them smooth with a little of the soup; then stir it into the rest; simmer it gently another quarter of an hour, season with salt, and it is ready. The flavour may be varied by any variety of herbs, or thickening with garlic or eschalot instead of celery; a larger portion of onions, or carrots and turnips, or rice, or paste, instead of oatmeal or barley.
 
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