Topics: Dietary experiments with a detail of soldiers from the United States army. General character of the army ration. Samples of the daily dietary adopted. Rate of nitrogen metabolism attained. Effect on body-weight. Nitrogen balance with lowered proteid consumption. Influence of low proteid on muscular strength of soldiers and athletes. Effect on fatigue. Effect on physical endurance. Fisher's experi merits on endurance. Dangers of underfeeding. Dietary observations on fruitarians. Observations on Japanese. Recent dietary changes in Japanese array and navy. Observations of Dr. Hunt on resistance of low proteid animals to poisons. Conclusions.

GENERAL acceptance of a new theory, or a new point of view, can be expected only when there is an adequate amount of scientific evidence on which the theory can safely rest. Facts cannot be ignored, and the larger the amount of supporting evidence the more certain becomes the general truth of the theory to which it points. Corroborative evidence, therefore, is always desirable, and be who would open up a new point of view must be zealous in accumulating facts to uphold his position. Critics there are without number who are ever ready to pick flaws in an argument or overturn a theory, especially if the one or thd other stands opposed to their own point of view. This, however, is highly advantageous for the advance of sound knowledge, since it necessarily prompts the advocate to search in all directions for added data, by which he can build a bulwark of fact sufficient to defy just criticism. Further, the true scientific spirit demands persistent and painstaking effort in the search after truth, that error and misconception may be avoided.

In harmony with these ideas, our attempt to ascertain the real needs of the body for proteid food led us to enlarge our evidence by a series of experiments with still another body of men, i. e., a detail of soldiers from the United States army.1 This was a somewhat more difficult and ambitious undertaking, since the number of subjects involved was larger, and because with this group of men we could not expect quite that high degree of intelligent co-operation afforded by the preceding subjects. Still, this very fact was in a sense an added inducement, since it offered the opportunity of experimenting with a body of men who naturally would not take kindly to anything that looked like deprivation, and whose continued co-operation could be expected only by satisfying their natural demands for food. If this could be accomplished by an intelligent prescription in their daily diet, and the experiment brought to a successful conclusion, with maintenance of body-weight, nitrogen equilibrium, health, strength, and general vigor; with an intake of proteid food essentially equal to that adopted by the preceding subjects, corroborative evidence of the highest value would be obtained.

The detail was composed of a detachment of twenty men from the Hospital Corps of the army, under the command of a first lieutenant and assistant surgeon. They were located in a convenient house near to the laboratory, where they lived during their six months' stay in New Haven, under military discipline, and subject to the constant surveillance of the commanding officer and the non-commissioned officers. Haying well-trained cooks and assistants,' with all necessary facilities for preparing and serving their food, with members of the laboratory staff to superintend the weighing of the food as it was placed before the men, and with intelligent clerks to attend to the many details connected with such an undertaking, a somewhat unique physiological experiment was started. Thirteen members of the detachment really took part in the experiment as subjects, and they represented a great variety of types: of different ages, nationalities, temperaments, and degrees of intelligence. They were men accustomed to living an active life under varying conditions, and they naturally had great liking for the pleasures of eating. Further, it should be remembered that, although the men had volunteered for the experiment, they had no personal interest whatever in the principles involved, and it could not be expected that they would willingly incommode themselves, or suffer any great amount of personal inconvenience. Again, there were necessary restrictions placed upon their movements, when relieved from duty, which constituted something of a hardship in the minds of many of the men and added to the irksomeness and monotony of their daily life. Regularity of life was insisted upon, and this was a condition which brought to some of the men a new experience. These facts are mentioned because their recital will help to make clear that, from the standpoint of the men, there were certain depressing influences connected with the experiment which would add to any personal discomfort caused by restriction of diet

1 In presenting the general results of these experiments, the writer has drawn freely from his book, " Physiological Economy in Nutrition" published by the Frederick A. Stokes Company, New York, 1904.

The ordinary army ration to which these men were accustomed was rich in proteid, especially in meat, and during the first few days they were allowed to follow their usual dietary habits, in order that data might be obtained bearing on their average food consumption. The details of one day's food intake will suffice to show the average character and amount of the food eaten per man:

Breakfast

Beefiteak 222 grama, gravy 68 grams, tried potatoea 234 gram*, onions 34 grams, bread 144 grams, coffee 679 grams, sugar 18 grams.

Dinner

Beef 171 grams, boiled potatoea 360 grams, oniom 56 grams, bread 234 grams, coffee 916 grama, sugar 27 grams.

Supper

Corned beef 195 grams. potatoea 170 grams, onions 21 grams. bread 168 grams, fruit jelly 107 grams, coffee 460 grams, sugar 21 grams.

It is not necessary to comment upon the large proportion of proteid matter in the day's ration; the three large portions of meat testify clearly enough to that fact, while the three equally large volumes of coffee indicate a natural disposition toward generous consumption of anything available. Habit, reinforced by inclination, had evidently placed these men on a high plane of food consumption.