Direct oxidation or combustion of the carbon and hydrogen contained in the food, or in the tissues themselves; the division of alimentary substances into respiratory, or non-azotized, and azotized, these doctrines are familiar even to the classes in our high-schools. But this simple statement is boldly questioned. Such is the well-grounded statement of Robin and Verdeil.

The last group consists also of nitrogenized substances, which resemble gelatine in many of their characteristics. The first two groups are called non-azotized, as they contain no nitrogen; the last two, azotized, containing nitrogen.

The division of food into azotized and non-azotized is no doubt important, but the attempt to show that the first only is plastic or nutritive, while the second is simply calorifacient, or heat-producing, fails entirely in the face of the facts revealed by the study of man in different climates, and of numerous experiments in the feeding of animals.

The division of food into azotized and non-azotized is no doubt important, but the attempt to show that the first only is plastic or nutritive, while the second is simply calorifacient, or heat-producing, fails entirely in the face of the facts revealed by the study of man in different climates, and of numerous experiments in the feeding of animals.

Direct oxidation or combustion of the carbon and hydrogen contained in the food, or in the tissues themselves; the division of alimentary substances into respiratory, or non-azotized, and azotized, these doctrines are familiar even to the classes in our high-schools. But this simple statement is boldly questioned. Such is the well-grounded statement of Robin and Verdeil.