16 NEW HAMPSHIRE EXPERIMENT STATION [Bull. 261 



tions of the amounts of total wa^^te are, therefore, somewhat smaller 

 than the true amounts. The edible waste, as thus collected, was placed 

 in a previouslj^ weighed container. When single or mixed meals were to 

 be studied, an exact duplicate of the meal or meals eaten by the indi- 

 vidual was placed in the weighed container. These samples of meals in- 

 cluded all foods eaten except bread, butter, and the beverage served, 

 which was usually tea, coffee, milk, or cocoa. This mixture was then 

 dried at a temperature not above that of boiling water until it became 

 seemingly drJ^ In the case of fatty mixtures, stirring with a previously 

 weighed knife or rod was necessary' during the drying process. When 

 the material had practically ceased to lose weight, it was allowed to 

 stand in the air of the room for several days until moisture equilibrium 

 with the room air was established and the weight of the material re- 

 mained approximately constant. This so-called "air-drj^" material was 

 used in all the combustions with the oxy-calorimeter, and hence all the 

 derived energy calculations have been based upon weights of air-dry 

 material. The exact quantity of water contained in the different air- 

 dry samples is not known, but for our special purpose this knowledge is 

 not necessaiy. In general, the moisture content was probably between 

 5 and 10 per cent. 



DISCUSSION OF RESULTS 



In the tables to be discussed in the following pages we have given 

 the sample number, a general description of the nature of the food 

 analyzed, the air-dry weight of the sample, the total protein content in 

 grams, the energy content per gram of air-dry matter, and the total 

 calories in the samjile. The energy values were obtained as explained 

 in our earlier report.^ Thus, the measured volume of oxygen consumed 

 per gram of air-dr>- matter was reduced to standard conditions of tem- 

 perature and pressure and corrected for the amount of nitrogen liberated 

 per gram of air-dry matter during the combustion. This corrected oxy- 

 gen value was then multiplied in most instances by the factor 4.825, the 

 caloric value of a liter of oxygen when mixed foods are burned. At 

 times excessively fat samples were burned. These will be specially com- 

 mented upon in the tables. So far as the accuracy of the above calcu- 

 lations is concerned, the exact composition of the material burned plays 

 no role, however, except when residues of an obviously fatty nature are 

 found. In these instances we have felt it more justifiable to employ the 

 factor 4.7 to represent the caloric value of a liter of oxygen, rather than 

 the conventional value of 4.825 used for all mixed foods. 



STUDY OF EDIBLE WASTE IN A FRATERNITY HOUSE 



In Table 1 are presented the results of analyses of edible waste 

 collected at a fraternity house during a period of seven days. Samples 

 were collected at each meal and brought to the laboratory daily for 

 analysis. The foods listed in the second column represent those recog- 

 nizable portions of food included in the samples. No attempt was 



'JJentdict and Farr, loc. clt. 



