I have taken this energy-producing power of food as the best basis for measurement and comparison. The nitrogen could have been taken as a unit, and the energy figured by a table, but it is simpler to use energy as a unit (as given in column 3, p. [655]), and figure the nitrogen in the various foods by means of a table which gives the amount of nitrogen per unit of energy. (Column 4, p. [655].)
Multiplication of units of energy (column 3) by the nitrogen factor (column 4) is necessary because the ratio of nitrogen to energy is different in each food.
EXPLANATION OF TABLE
In the table that follows, I have attempted to give in the simplest way the amount of each particular food that one vieno equals.
The second column shows, in the plainest language possible, what one vieno of food equals—as, one vieno of barley equals one ounce; or, one vieno of nuts equals one rounded tablespoonful, etc. This method is, of course, only approximate, as in some foods it is impossible to find a simple term to express the amount of one vieno. This is especially true of cooked foods because of the varied amounts of water contained. In such cases the way for the student to become familiar with a vieno is to weigh one pound of the raw material, and, after it is cooked, weigh it again, and then calculate the water content.
The definition given in the second column in the case of milk, butter, eggs, and cheese is fairly accurate. The description given in the case of cereals and bread is also fairly accurate. In the list of fresh vegetables, no attempt has been made to describe one vieno by volume, as, vegetables being loose and bulky, it is practical to measure them only by weight.
Only the edible portion of food considered
In the case of fresh fruits, one vieno has been defined as "one large orange" or "six plums," etc. In such cases allowance for the non-edible portion has been made; all weights given in the table consider only the edible portion.