According to Mattieu Williams, scurvy prevailed in Norway to a very serious extent until the introduction of the potato; and Lang, with other good authorities, testifies that its disappearance is due to the use of potatoes by a people who formerly were insufficiently supplied with salts-giving vegetable food. The salts of the potato are most abundant in or near the skin, and the decision of the question as to whether potatoes shall be pared or not before cooking is somewhat aided by this fact. For persons who eat but few other fresh vegetables by all means leave the skins on, but for those who have access to a good kitchen garden and have plenty of other vegetables and fruits from which to get their salts, it makes no important difference whether the skins are removed. The potato is eminently a starch food, and this knowledge indicates the method of treatment in cooking. Since starch is its principal ingredient (the amount of nitrogenous matter being very small), if it is cooked with reference to that alone, it will be done in the best possible manner. Starch, in order to be rendered most digestible and acceptable to the human system, must be subjected to a high temperature in the presence of some liquid. At 401° Fahr. (see pages 33 and 34) it is converted into dextrine. This change, if not performed outside the body, will be done in the ordinary processes of digestion after the starch is eaten; therefore the nearer we approach to it in cooking, the more perfectly is the food prepared which contains it. Usually the first vegetable prescribed by the physician for a sick person who is beginning to use solids, is a baked potato. A baked potato, however, may be no better than a boiled potato unless it is cooked in so high a temperature that the starch is affected. Boiled potatoes cannot be subjected to a higher temperature than 212° Fahr. Baked potatoes may be done in such a way that they are but little better than boiled--for instance, done in a slow oven. On the other hand, if they are put into a temperature of 380° or 400° Fahr., or a hot oven, they will be done in such a manner that the conversion of starch will in a degree take place, and they will be consequently both palatable and easily digested.