In reference to chocolate, much difference of opinion has hitherto existed as to its nutritious properties; but we know by experience that it is easy of digestion, and eminently suited to such as are subject to great mental exertion. Some dietists have held that chocolate has a tendency to prevent any augmentation of corpulency. When made with water, it is decidedly preferable to coffee made with milk, the latter being productive of fat. Milk, by virtue of its composition, combines all the elements which are fitted for the development and nutrition of the body; casein containing nitrogen, a fatty matter (butter), and a saccharine substance (sugar of milk). Chemistry reveals the remarkable fact, that the composition of casein or the cheesy portion of milk, is identical with that of the fibrin and albumen of the blood. Under this aspect, therefore, milk is very nutritious. The sugar and butter which exist in milk, have no analogy with flesh; according to analysis, they are composed of carbon and the elements of water. When, therefore, we partake of milk, we obtain in one and the same substance all the elements which are necessary for the growth and nutrition of the body, and such is the case in infant life. Since, however, both carbon and hydrogen, in very large proportion, enter into the composition of milk, it is advisable, whenever there is a manifest tendency to corpulence, that the use of it as an article of diet should be avoided. Infants are usually fat, owing to the elements of adipose matter forming so large a proportion of their food, whether that consist of milk alone, or in combination with starchy or farinaceous and saccharine substances. CHAPTER VIII.