Whatever the elusive factor may be which constitutes the freshness of a dietetic article, it is to be found in the juices not only of fresh fruit, but also of raw meat and uncooked vegetables. Raw meat juice separated from the solid proteins will not only prevent tuberculised dogs from succumbing to the disease, but will enable them to remain in robust health, whereas when fed on muscle fibre minus the juice, even to the extent of 2 or 3 pounds daily, they quickly collapse. A piece of raw cabbage inoculated with human faeces and placed in an incubator at the temperature of the body inhibits the growth of putrefactive organisms, whereas in a cooked cabbage in similar circumstances the number of putrefactive germs increases enormously. This would suggest that raw foods are capable of exercising a wholesome influence in the alimentary canal, by inhibiting the development of toxins readily generated there by the action of germs upon cooked foods.

On the other hand, on account of the large content of cellulose they are by no means easily digested, and probably in this reason lies the value of raw foods more than in the mysterious factor of vitality. In the nutrition of the carnivora and omnivora cellulose is of minor importance, whereas the herbivora obtain quite a considerable proportion of their carbohydrate in the form of cellulose. As it is believed that none of the digestive fluids are capable of dissolving cellulose, it is requisite for us to consider the mode in which it is likely to be prepared for utilisation by the body.