In Chittenden's experiments there was no analysis of the expired air, and conclusions are drawn from the maintenance of body weight.

Several of the larger-sized soldiers (those who weighed 70 kilograms) lost between 3.5 and 8.5 kilograms of body weight during the experiments. Fritz, weighing 76.0 kilograms, lost 3.6 kilograms in five months. Had this all been fat, one can estimate that its heat value would have been 33,480 calories, or an available daily combustion of body substance equal to 223 calories. Conclusions drawn from weight alone can be of only the roughest character (see p. 273).

For ordinary laborers, working eight to ten hours a day, such as mechanics, porters, joiners, soldiers in garrison, and farmers, 3000 calories does not seem an excessive quantity.

Rubner's diet calls for 2868 calories. Chittenden's allowance (2500-2600) is too low, while Atwater's (3400) approximates that required by a farmer.

A third class are men at hard labor, such as soldiers in the field, shoemakers, blacksmiths, etc. For these Voit allows a dietary containing 3574 calories; Rubner, 3362 calories; and Atwater, 4150 calories. The differences in these figures are merely differences in the quantity of work alone.

In almost all the rations given carbohydrates do not exceed 500 grams. The remainder is made up of fat.

Atwater1 reports the following dietaries for farmers:

To this list may be added for farmers in Finland 3474 calories, as found in the exhaustive studies of Sundstrom.2 He states that the diet of the average Finnish peasant contains 136 grams of protein, 83 grams of fat, and 580 grams of carbohydrates, which corresponds to a division of calories so that protein furnishes 15 per cent., fat 21 per cent., and carbohydrates 64 per cent, of the total. He notes that if the peasant's requirement of energy were taken in rye bread alone 124 grams of protein would be ingested with it, whereas if a milk diet covered the requirement 195 grams of protein would be taken. He, therefore, sees no outlook for a low protein dietary among the poorer classes, that have hard work to do and must ingest large quantities of food fuel.

Woods and Mansfield3 report a dietary study of a camp of fifty Maine lumbermen actively engaged in chopping and yarding logs. The investigation continued for six days. The daily average ration per man was as follows: Protein, 164.1 grams; fat, 387.8 grams; carbohydrates, 982.0 grams; calories, 8083 This dietary would appear almost fabulous were it not for the fact that Atwater has actually shown that a metabolism equivalent to 9300 calories a day may be produced by a man riding a stationary bicycle for sixteen hours.

Becker and Hamalainen4 in Finland have shown how much energy is needed by people in various occupations. The women may be first considered. The work day was of eight hours:

1 Atwater: Report of Starr's Agricultural Station, 1902-03, p. 135. 2 Sundstrom: "Untersuchungen uber die Ernahrung der Landbevolkerung in Finland," 1908. 3 Woods and Mansfield, Lot. oil.

4 Becker and Hamalainen: "Skan. Archiv fur Physiologie," 1914, xxxi, 198.

A seamstress sewing with a needle required 1800 calories.

Two seamstresses, using a sewing machine, required 1900 and 2100 calories, respectively.

Two bookbinders required 1900 and 2100 calories.

Two household servants, employed in such occupations as cleaning windows and floors, scouring knives, forks, and spoons, scouring copper and iron pots, required 2300 to 2900 calories.

Two washerwomen, the same servants as the last named, required 2600 and 3400 calories in the fulfilment of their daily work.

Concerning the fuel requirement for the occupations of men:

Two tailors required 2400 to 2500 calories.

A bookbinder required 2700 and a shoemaker 2800.

Two metal workers, filing and hammering metals, required 3100 and 3200 calories.

Two painters, occupied in painting furniture, required 3200 and 3300 calories, and two carpenters engaged in making tables required the same amount of energy.

Two stonemasons chiseling a tombstone needed 4,300 and 4700 calories.

Two men sawing wood required 5000 and 5400 calories.

The proverbial reputation of sawing wood as a strenuous occupation has here its scientific verification and explains the disinclination of the hungry to engage in this useful occupation, as well as the unpopularity of charitable wood yards.

Carpenter1 has investigated the energy required for typewriting. He finds that the increase in oxygen absorption, above the amount when the typist is sitting and reading, amounts to about 2.47 grams, or the equivalent of 8 calories per thousand words when the speed is fifty words per minute. This would aggregate 24 calories per hour or 192 calories for eight hours. This quantity of energy is about the equivalent of that necessary for the forward progression of an average man walking horizontally for one hour and ten minutes at a speed of 2.7 miles an hour; the expenditure of energy in typing is therefore slight.

1 Carpenter: "Journal of Biological Chemistry," 1911, ix, 231.

A lower ration than the lowest here mentioned may be allowed to one who is confined to his bed (p. no). In many hospitals, however, it has been found that liberal feeding of the very poor is often better than medicine.

The "standard" dietaries are given below, not because they are inflexible requirements in any sense of the word, but merely for the convenience of the reader. The individual standard will ever be controlled by climate, the amount and kind of mechanical effort; by appetite, purse and dietetic prejudice.

Standard Dietaries For A Man Of 70 Kilograms

*Carbohydrates and fats to make up the fuel value.