The vegetable kingdom greatly exceeds the animal in the number and variety of the aliments which it furnishes to man. It is well known that the four essential elements, carbon, oxygen, hydrogen and nitrogen, which form an important part of all animal compounds, are also to be found in great abundance in all vegetable compounds; it is owing to this fact that different animals are nourished equally well on an exclusive diet of either. The lion, tiger and other animals which live exclusively on animal food, give no evidence of being better nourished than the deer, the ox, and animals which subsist wholly on vegetable food; but the apparatus for digestion in each class is constructed with an evident adaptation to the kind of diet on which the different animals subsist. In man the digestive apparatus is more extensive than in flesh-eating animals, but is less complicated than in those which are confined to vegetable food alone. Man is therefore omnivorous, both in his structure and in his habits. But the universal tendency of mankind gives preference to a mixed diet. The most perfect development and the greatest individual vigor are to be found among those races in which a mixed diet is the prevalent habit. During the warm season vegetables and fruits may be made the means of great mischief or of great good. Perfectly ripe fruits or vegetables are highly useful and well adapted to the wants of the system at that season of the year; yet they may become, and often are, a prolific source of disease. So frequently is this kind of food a cause of bowel complaint that city physicians discard it wholly from the diet of children not under their immediate supervision. Vegetables and early fruits that have been long exposed, in a malarious or filthy market, or in transportation, are unquestionably dangerous articles of food for all persons. But the injurious consequences which follow the use of ripe and wholesome vegetables and fruit are, in almost all cases, the results of imprudence. They are either in an improper condition to be used as food, or the quantity is too great, or they are taken at improper hours. In either case there is a great change in the usual diet. Instead of a lack of refrigerant food, there is now an excess of it. Active fermentation takes place in the process of digestion, and results in serious derangement in the alimentary canal, which leads to cholera morbus, diarrhœa or dysentery. During warm weather vegetables and fruit are to be regarded as safe only when used as an accompaniment to other food; they are not adapted to meet all the wants of the system, and therefore should not constitute a full meal at any time. In the country, where this kind of food is enjoyed daily in a proper condition to be eaten, injurious consequences are quite rare, and then they are the result of an excess, or of an indulgence of an appetite at irregular hours.