In this particular period of six days, the body was really gaining a little nitrogen, i. e., storing away a small amount of proteid for future use, although it may be granted that the amount was too small to have any special significance. During this period, the average daily intake of nitrogen was 6.4 grams, equal to 40 grams of proteid food. The average daily output of nitrogen through kidneys and excrement was 6.24 grams. The average daily output of metabolized nitrogen, through the kidneys, was 5.44 grams, corresponding to the breaking down of 34 grams of proteid material. Further, it should be stated that the total calorific value of the daily food during this period was less than 2000 calories. Let me add now a final balance period taken at the close of the nine months' trial:

In this period of five days, the average daily intake of nitrogen was 5.86 grams, corresponding to 86.6 grams of proteid food. The average daily output of metabolized nitrogen was 4.92 grams, implying the breaking down in the body of only 80.7 grams of proteid material per day. The fuel value of the daily food, calculated as closely as possible, was less than 2000 calories. The body was essentially in nitrogen equilibrium, the minus balance being too small to have any special significance.

It will be instructive to consider next the actual character and amount of the diet made use of on several of these balance days:

March 21. Breakfast

Coffee 119 grami, cream 90 grams, sugar 9 grama.

Lunch

One shredded wheat biscuit 31 grams, cream 116 grams, wheat gem 83 grama, butter 7 grams, tea 135 grams, sugar 10 grama, cream cake 63 grams.

Dinner

Pea soup 114 grams, lamb chop 24 grams, boiled sweet potato 47 grams, wheat gems 76 grams, butter 18 grams, cream cake 62 grama, coffee 61 grams, sugar 10 grams, cheese crackers 16 grams.

Total nitrogen content of the day's food = 6.621 grams.

June 24. Breakfast

Coffee 96 grams, cream 82 grams, sugar 8 grams.

Lunch

Creamed codfish 89 grams, baked potato 95 grams, butter 10 grama, hominy gems 68 grams, strawberries 86 grams, sugar 26 grams, ginger snaps 47 grams, water.

Dinner

Cold tongue 14 grams, fried potato 48 grams, peas 60 grams, wheat gems 30 grams, butter 11 grams, lettuce-orange salad with mayonnaise dressing 166 grams, crackers 22 grams, cream cheese 14 grams, ginger snaps 22 grams, coffee 68 grams, sugar 10 grams.

Total nitrogen content of the day's food = 6.331 grama.

June 25. Breakfast

Coffee 101 grams, cream 86 grams, sugar 13 grams.

Lunch

Omelette 60 grams, bacon 9 grams, French fried potato 23 grams, biscuit 29 grams, butter 8 grams, ginger snaps 42 grams, cream cheese 17 grams, iced tea 160 grams, sugar 16 grams.

Dinner

Wheat popovers 67 grams, butter 10 grams, lettuce-orange salad with mayonnaise dressing 147 grams, crackers 22 grams, cream cheese

21 grams, cottage pudding 82 grams, coffee 48 grams, sugar 11 grams.

Total nitrogen content of the day's food = 4.941 grams.

June 27. Breakfast

Coffee 112 grams, cream 22 grams, sugar 10 grams.

Lunch

Raul lamb 9 grams, baked potato 90 grams, wheat genu 47 grama, butter 12 grams, iced tea 250 grams, sugar 25 grama, vanilla eclair 47

Dinner

Lamb chop 32 grams, creamed potato 107 grams, aiparagus 49 grams, bread 35 grams, butter 17 grams, lettuce-orange salad with mayonnaise drening 160 grams, crackers 21 grams, cream cheese 12 grama, Coffee 63 grams, sugar 9 grams.

Total nitrogen content of the day'a food = 5.486 grams

It can be seen that there was nothing especially peculiar in these dietaries, aside from their simplicity, except that the quantities were small, Meat was not excluded; there Was do approach to a cereal diet; there were no fads involved, nothing but simple moderation in the amounts of nitrogen-containing foods. Further, there was perfect freedom of choice; full latitude to consider personal likes and dislikes in the selection of foods; anything that appealed to the appetite could be eaten, with the simple restriction that the amount taken must be small. Duriug the balance days, naturally, every article of food had to be carefully weighed and analyzed, which fact undoubtedly tended to limit in some degree the variety of foods chosen, since increase in the number of articles meant increased labor in analysis. Quite noticeable, however, was the extreme constancy in the nitrogen-content of the daily diet, even on those days when the food was not weighed. In other words, there had been gradually acquired a new habit of food consumption, and the individual, unconsciously perhaps, rarely overstepped the limits fixed by the new level of proteid metabolism. This is a fact that has been conspicuous in nearly all of our experiments, where freedom of choice in the taking of food has been followed; and is in harmony with the view that after a lower level of proteid metabolism bas once been established, and the body has become accustomed to the new conditions, there is little tendency for any marked deviation from the new standards of food consumption.

With maintenance of body-weight, together with nitrogen equilibrium through all these months; and with health, strength, and mental and physical vigor unimpaired, there is certainly ground for the belief that the real needs of the body were as fully met by the lowered consumption of proteid food as by the quantities called for by the customary standards. Finally, it should be noted that this particular subject was small in weight, and hence did not need so much proteid as a man of heavier body-weight would require. In recognizing this principle, we may for future comparison calculate the nitrogen requirement of the body, on the basis of the present results, per kilo of body-weight With the weight of the subject placed at 57 kilos, and with an average daily excretion of nitrogen amounting to practically 5.7 grams, it is plain that this individual was quite able to maintain a condition of equilibrium with a metabolism of 0.1 gram of nitrogen per kilo of body-weight. Translated into terms of proteid matter, this would mean a utilization by the body of 0.625 gram of proteid daily per kilo of body-weight Regarding the fuel value of. the daily food, we need not be more precise than to emphasize the fact that so far as could be determined, on the basis of chemical composition, the heat value of the food rarely exceeded 1900 calories per day. If we make a liberal allowance, for the sake of precaution, it would seem quite safe to say that this particular individual, under the conditions of life and bodily activity prevailing, did not apparently need of fuel value more than 2000 calories per day, which would correspond to 35 calories per kilo of body-weighty