Potatoes.—Take a sound-looking potato of any variety; pay but little attention to its outward appearance; cut or break it in two, crosswise, and examine the cut surface. If it appears watery to such a degree that a slight pressure would cause water to fall off in drops, reject it, as it would be of little use for the table. A good potato should be of a light cream-color, and when rubbed together a white froth should appear round the edges and surface of the cut, which indicates the presence of starch. The more starch in the potato, the more it will froth; consequently the more froth on the potato the better it will be when cooked. The strength of its starchy properties may be tested by releasing the hold of one end, and if it clings to the other, the potato is a good one. These are the general principles followed by potato-buyers, and they are usually to be fully relied upon. About one seventh part of the potato is nutritious, and this is chiefly farinaceous, and is accompanied by no inconsiderable portion of saline matter, more especially of potassa, which renders it highly antiscorbutic, and a powerful corrective of the grossness of animal food. When forming part of a mixed diet, no substance is more wholesome than the potato. Even the wild potato found in the Yellowstone Country is thought one of the best of edible wild roots.Boiled Potatoes.—To retain the highest amount of nourishment, potatoes should be boiled with their skins on. When so treated, they are twice as rich in potassa salts as those which have first been peeled. It is a good plan to place them in the oven or on top of the range after boiling them, thereby allowing all surplus moisture to escape. Before sending to table they should be peeled, and, if convenient, thoroughly mashed, as they are more easily digested, and when they are lumpy or watery they escape proper mastication, and in this way cause serious derangement of the system. Under no circumstances allow the aged, dyspeptic, or those in delicate health to eat them except when mashed. The so-called potato "with a bone in it," a favorite dish of the Irish peasant, is a potato only half cooked, being raw in the centre; and a more indigestible thing cannot well be imagined.Lyonnaise Potatoes.—The same as sautÉed, except that a little onion is fried brown and the potato then added.Potatoes au Cochon.—Slice two hot, mealy potatoes; cut the slices into squares; put them in a saucepan, and add scalded cream enough to cover them, salt, and white pepper. Cut into very small pieces half an ounce of fat, boiled, salt pork; add a tablespoonful to the potato; simmer until thoroughly blended together; pour the contents of the dish into a small au gratin dish (or vegetable baker); grate a little Parmesan cheese over it; add a small bit of butter; place in the oven a moment to brown, and serve in the same dish.Potatoes au Gratin.—Nearly fill the gratin pan with hot boiled potatoes, cut into small pieces; cover with milk; strew over them grated cheese or part cheese and grated crumbs; add a little butter, and bake brown in a quick oven.Potatoes SautÉed are cold boiled potatoes cut into small slices and slightly browned in a frying-pan, shaped, and turned out on a hot dish (as you would an omelet), and seasoned with parsley, salt, and pepper.