“Perhaps some discouraged reader may ask, What can I eat? Well, I don't pretend to direct people's diet. Ask your doctor, if you can't find out. But I will suggest that there are a few things that can't be adulterated. You can't adulterate an egg, nor an oyster, nor an apple, nor a potato, nor a salt codfish; and if they are spoiled they will notify you themselves! and when good, they are all good healthy food. In short, one good safeguard is, to use, as far as you can, things with their life in them when you buy them, whether vegetable or animal. The next best rule against these adulteration-humbugs is, to buy goods crude instead of manufactured; coffee, and pepper, and spices, etc., whole instead of ground, for instance. Thus, though you give more work, you buy purity with it. And lastly, there are various chemical processes, and the microscope, to detect adulterations; and milk, in particular, may always be tested by a lactometer,--a simple little instrument which the milkmen use, which costs a few shillings, and which tells the story in an instant. It is a glass bulb, with a stem above and a scale on it, and a weight below. In good average milk, at sixty degrees of heat, the lactometer floats at twenty on its scale; and in poorer milk, at from that figure down. If it floats at fifteen, the milk is one-fourth water; if at ten, one half.”
A cook of roughly the same moment, setting down the same dish.
Boil a dessert spoonful of ground coffee, in nearly a pint of milk, a quarter of an hour; then put into it a shaving or two of isinglass, and clear it. Let it boil a few minutes, and set it on the side of the fire to grow fine. This is a very fine breakfast. It should be sweetened with real Lisbon sugar of a good quality.
Sources: The passage is from P. T. (Phineas Taylor) Barnum, The Humbugs of the World: An Account of Humbugs, Delusions, Imposition, free to read in full at Project Gutenberg. The recipe is from Rundell, New system of domestic cookery, formed upon principles of of 1806, also free in full. Both are in the public domain in the United States. The binding above is ours — oxblood cloth, oyster stamp.