370 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



remainino; eight hours of the day were devoted to gomg to and from 

 work, eating, sitting, etc., corresponding, say, to six hours of rest and 

 two hours at Hght muscular exercise, the carbon dioxid output will 

 be six times the average amount eliminated per hour at rest, that is, 

 6 by 35 = 210 grams, and two times the amount given off at light 

 work, 2 by 55=110 grams. The total for the twentj^-four hours 

 would obviously be the sum of the quantities mentioned above, or 

 2,200 grams. The heat eliminated in the twenty-four hours b}^ men 

 at very severe work may be likewise calculated by multiplying the 

 time devoted to sleep, work, etc., by the average hourly output. In 

 eight hours at sleep he would eliminate 520 calories (8 by 65 = 520); 

 in eight hours at work, 4,800 calories (8 by 600 = 4,800) ; in six hours 

 of rest, 600 calories (6 by 100 = 600); and in two hours at light exer- 

 cise, 340 calories (2 by 170 = 340); making a total for the twenty-four 

 hours of 6,260 calories. 



The investigations made in connection with the respiration calorim- 

 eter have furnished the most accurate records jet available of the 

 normal diurnal variations in body temperature. A summary of this 

 work and a discussion of the results which apply to problems of 

 ventilation and other topics have been included in a recent publica- 

 tion of the Department." 



SPECIAL STUDIES OF CEREALS, LEGUMES, MEAT, FRUIT, AND 



NUTS. 



As regards the results of special investigations, particular interest 

 attaches to the studies of the digestibility and nutritive value of cereal 

 products. The extensive investigations which have been made with 

 different grades of flour have slK)\\'n that when gromid from the same 

 lot of wheat the standard patent flour furnishes slightly less protein 

 and mineral matter than the coarser flours but surpasses them in 

 digestibility, and so may be fairly said to have a somewhat higher 

 nutritive value pound for pound. The coarser flours have a somewhat 

 laxative effect, which is commonly attributed to their bran content, 

 and are useful in the diet in this way and for the v^iriety which they 

 give. In general, it may be said that flours of all soris are nutritious 

 and wholesome and among the most important constituents of the 

 diet. 



The investigations with cereal breakfast fooils have shown that 

 this class of goods so much used at the present tiin*^ may constitute 

 an important source of nutritive material, and that althougii the 

 individual products difl"er less among themselves in nutritive material 

 than is conunonly supposed, as a whole they are nutritious and 

 directly comparable with flours of various typos. The breakfast 

 foods in which the coarser part of the grain has been removed have 



"U. S. Dcpt. Agr. Yearbook, 1904, p. 205. 



