May, 1929] FOODS IN A COLLEGE COMMUNITY 7 



A large number of calories are obtained each day by college stu- 

 dents and by other individuals in "extra foods," such as candies and 

 ice cream, taken apart from the regular meals. 1 Some of these 

 foods are highly standardized, particularly the candies wrapped in 

 packages and sold for five or ten cents. Because of the wide use of 

 these extra foods, our study also included as comprehensive analyses 

 of them as possible. 



The foods analyzed are characteristic of those eaten by many 

 individuals other than college students; for in American urban life 

 the old-fashioned kitchen is being superseded by the modern kitchen- 

 ette, the cafeteria, and the quick lunch, and the use of delicatessen 

 and drug-store foods and the so-called "extra foods" is now wide- 

 spread. The results of our research, therefore, although secured in 

 essentially one locality, are believed to be representative of the 

 •energy values of many of the present-day, somewhat standardized 

 foods, regardless of locality. 



APPARATUS USED IN THIS RESEARCH 



The apparatus which we have used for measurement of the 

 oxygen consumption during food combustions is called the "oxy- 

 calorimeter." It has already been described elsewhere in detail, 2 

 but inasmuch as it was first put to practical and extensive use in this 

 particular research, we will give here a brief outline of its general 

 principle and an account of such modifications in the technique as 

 have seemed desirable since the publication of the detailed description. 



The principle of the oxy-calorimeter is based upon the fact that 

 dry organic material burns freely in an atmosphere of pure or 

 nearly pure oxygen at oi'dinary atmospheric pressure, provided the 

 chief product of combustion (carbon dioxide) is removed rapidly and 

 the flame is fed with air relatively rich in oxygen. The oxy-calori- 

 meter (See Fig. 1) consists of a small combustion chamber, A, a heat- 

 resistant glass (pyrex) lamp chimney with its lower end in a water 

 seal. A current of oxygen-rich air enters this combustion chamber at 

 the top, leaves at the bottom, and passes through two bottles, B, B, 

 containing soda-lime where the carbon dioxide produced by the com- 

 bustion is completely absorbed. The air then enters a small rotary 

 (suction) blower, C, from which it is discharged into the top of the 

 chamber, thus making a complete circuit. A delicately counterpoised 

 spirometer, D, is connected to the pipe leading from the blower to 



(1) See Benedict, C. G., and P. G. Benedict, Boston Med. and Surg. 

 Journ., 1918, 179, p. 153; ibid., 1919, 181, p. 415; ibid., 1921, 184, p. 436. 



(2) Benedict, F. G., and B. L. Fox, Indus, and Eng. Chem., 1925, 17, p. 

 912; Benedict, F. G., and E. L. Fox, Journ. Biol. Chem., 1925, 66, p. 783; 

 Benedict, F. G., Abderhalden's Handb. d. biolog. Arbeitsmethoden. Abt. IV, 

 Teil 13, 1929, p. 51. 



