The Book of Household Management by Mrs. Beeton

quart of mushrooms, 2 blades of pounded mace, 1 oz. of ground pepper, salt to taste. _Mode_.--Choose some nice young button mushrooms for pickling, and rub off the skin with a piece of flannel and salt, and cut off the stalks; if very large, take out the red inside, and reject the black ones, as they are too old. Put them in a stewpan, sprinkle salt over them, with pounded mace and pepper in the above proportion; shake them well over a clear fire until the liquor flows, and keep them there until it is all dried up again; then add as much vinegar as will cover them; just let it simmer for 1 minute, and store it away in stone jars for use. When cold, tie down with bladder and keep in a dry place; they will remain good for a length of time, and are generally considered delicious. _Seasonable_.--Make this the same time as ketchup, from the beginning of September to the middle of October. NATURE OF THE MUSHROOM.--Locality has evidently a considerable influence on the nature of the juices of the mushroom; for it has been discovered, after fatal experience, that some species, which are perfectly harmless when raised in open meadows and pasturelands, become virulently poisonous when they happen to grow in contact with stagnant water or putrescent animal and vegetable substances. What the precise nature of the poison in fungi may be, has not been accurately ascertained. A VERY RICH AND GOOD MUSHROOM SAUCE, to serve with Fowls or Rabbits.