8 



The bill of fare was varied every day, but recurred regularly in seven- 

 day periods. This arrangement avoided the monotony of eating the 

 same character of food on successive days, and, at the same time,-! 

 favored simplicity by the regularly recurrent use of established rations! 

 This was convenient, both for the cook and for the steward, to guide in 

 the one case in the methods of the preparation of the food, and, in the 

 other, to determine the character of the supplies to be purchased. 



Two rooms in the basement of the laboratory building were equipped 

 as kitchen and dining room respectively. The kitchen was supplied with 

 two gas ranges and a full supply of culinary utensils. The dining 

 room was plainly, yet substantially, furnished with the necessary articles 

 for preparing a table in a neat, attractive, but not expensive manner. 



SERIES AND PERIODS OF OBSERVATION. 



Three divisions were made of each series of observations, namely, 

 fore period, preservative period, and after period. The time assigned 

 to each of these periods varied, and the total time of the three periods 

 varied from 30 to 70 days. 



During the entire time of observation the rations of each member of? 

 the table were carefully weighed or measured, and the excreta collected. 



The object of the " fore .period " was to determine as nearly as possi- 

 ble the quantity of food required to maintain the body weight at 

 nearly a constant figure, and to determine the normal metabolism as a 

 basis of comparison with that of the preservative period. Preceding 

 the fore period the quantities of food freely chosen by each individual 

 were noted, so that some idea might be formed of the proper amount 

 to be weighed or measured. If it was evident that too much food had 

 been habitually consumed, keeping the body in a plethoric state, the 

 rations were cut down somewhat in order that this condition might be 

 removed. The quantity of the ration was, therefore, varied either by 1 

 increase or decrease, until at the end of about ten days there was no, 

 very marked daily change in weight. It was found impracticable, howJ 

 ever, to secure an absolute constancy of body weight, since the climatic 

 conditions, slight differences in the amount of exercise, and variations 

 in the quantity of excreta all combined to produce Variations in weight 

 (as ascertained at any given period of the day), which are more or less 

 independent of the actual quantity of food consumed. In order that 

 these daily variations may be eliminated from consideration in the com- 

 parison of data, the average weight for the "fore period" is taken as 

 the initial point. 



The quantity of the ration having been thus determined by the 

 observations of the "fore period" the " preservative -period " is entered 

 upon. During this time the quantity of ration previously determined 

 is given without variation, except in case of sickness or some unavoid- 

 able condition, and to this ration a certain quantity of the preservative 

 to be studied is added. 



