The importance of the vitamines in nutrition has been very clearly demonstrated in experiments upon animals, and these experiments have been repeated a sufficient number of times to be conclusive. Animals have been fed upon pure protein, fat, carbohydrate, and salts, but with vitamine removed or destroyed; and although receiving calories enough, they fail to keep up their nutrition. With a simple change of dietary to include a small amount of food containing the vitamine, without any change in the total calories eaten, their nutrition improves quickly, and they come back to a normal state. Foods rich in vitamine are represented by milk, fresh vegetables, fresh fruits, and whole grain products. Foods poor in these substances are represented by sterilized and preserved milks, dried fruits, dried vegetables, white flour, and polished rice. Vitamines are reduced or lost by the following processes in the preparation of foods: taking off the coating of grain, overheating, washing out in cooking, and drying. _Importance of Water_ Water, although not a food in the sense of yielding fuel value to the body, is a most important agent in all the various chemical processes taking place in the tissues. Water is the universal solvent; and because of this property, it carries both food and waste to and from the tissues. The average person needs from three to five quarts a day, a part of which is taken as a portion of the food eaten. This leaves from three to five pints to be taken as a drink. Good drinking water should be colorless, odorless, and of an agreeable taste; should be free from organic matter, poisonous metals, and the bacteria of disease; and should be low in nonpoisonous mineral salts--that is, should be reasonably soft. There are three common classes of water that are used for drinking purposes; namely, rain water, surface water, and ground water. Rain water is the purest if properly collected. Surface water--water from lakes, streams, etc.--is most likely to be contaminated with organic matter and bacteria. Ground water--that is, water from springs and wells--is likely to be the hardest, but is usually free from bacteria of disease unless there is some contamination from the surface. To take a fairly good quantity of water between meals is better than to drink too freely at the meal hour. Great care should be taken in selecting the supply of drinking water, as when contaminated, it is a very fruitful means for the transmission of diseases, particularly such diseases as typhoid fever. If not certain of the purity of a water supply, one can be sure to destroy all the disease-producing bacteria by boiling the water for a few minutes, then cooling, and drinking as usual. _Simple Dietetic Principles_ 1. Food should be pleasant to the sight and the taste. 2. Eat slowly. Masticate thoroughly. 3. Do not wash down your food with water or any kind of beverage.