lee STORRS AGRICULTURAL EXPERIMENT STATION. 
the fats 9.3 calories of potential energy per gram. ‘These cor- 
respond to 1,860 calories for one pound of protein or carbohy- 
drates and 4,220 calories for one pound of fats. 
Waste.—The words ‘‘refuse’’ and ‘‘ waste”’ are used some- 
what indiscriminately. In general, refuse in animal food repre- 
sents inedible material, although bone, tendon, etc., which are 
classed as refuse, may be utilized for soup. The refuse of veg- 
etable foods, such as parings, seeds, etc., represent not only 
inedible material, but also more or less of edible material. The 
waste includes the edible portion of the food, as pieces of meat, 
bread, etc., which might be saved, but is actually thrown away 
with the refuse. 
In the studies here described the refuse and waste were sep- 
arated so far as practicable and the latter was collected, dried, 
and analyzed. No attempt has been made in these investiga- 
tions until recently to keep the animal wastes and the vegetable 
wastes separate, but rough calculations have been made of the 
nutrients of the waste which came from the animal and of 
those which came from the vegetable food.* Inasmuch, how- 
ever, as different families do not waste the same kinds of food 
in the same proportions, the plan has been adopted of separ- 
ating the animal and vegetable wastes wherever. practicable. 
But while this latter method gives the actual amount of 
animal and vegetable protein and carbohydrates wasted, it- 
does not necessarily show the relative amounts of animal and 
vegetable fat wasted, because of the use of animal fats such as 
those in suet, lard, butter, and milk, in the cooking of vege- 
table foods such as bread, cake, etc. It follows, therefore, 
that the vegetable waste may contain a considerable amount of 
animal fat. This was shown in an exaggerated form in dietary 
studies recently made at the Maine State Colleget where, in 
one instance, the fat in the vegetable waste, largely bread and 
pastry, was larger than the actual amount of fat in the raw 
material of the vegetable foods consumed. No attempt is here 
made to distinguish between animal and vegetable fat in the 
wastes, 
* See Report of this Station, 1895, PP. 131, 132. 
+ Bulletin No. 37, Office of Experiment Stations, U. S. Department of Agriculture. 

