78 STORRS AGRICULTURAL EXPERIMENT STATION, 
proportions of proteids and non-proteids as well as upon the 
percentages of nitrogen in each. In the animal foods and in 
the cereal grains the difference between the amounts of true 
proteids and the amounts of protein, which include in addition 
the non-proteids, is so small that little error is introduced in 
multiplying the total nitrogen by the factor for the proteids 
in estimating the total protein. In considering the nutritive 
value of the nitrogenous matter of the vegetables and the 
fruits, however, the case is quite different, since the non- 
proteids appear to form something like one-fourth of the total 
nitrogenous matter. Indeed, in view of the fact that the pro- 
tein is commonly taken as the measure of the tissue forming 
material of the food, it might be more nearly correct to consider 
simply the proteids in the vegetables and fruits, either leaving 
the non-proteids out of .account entirely or including them 
with the fats and carbohydrates as fuel ingredients. But since 
some of the non-proteids occurring in vegetables may have a 
special value as protectors of the protein of the body or of food 
from consumption there is a partial excuse for including them 
in the estimates for protein of these foods until more exact 
information regarding their Composition and nutritive values 
shall accumulate. 
The nitrogen factor for vegetables and fruits, however, will 
be quite different from that for animal foods or for cereal 
products. If we suppose that 60 per cent. of the nitrogen of 
the vegetables is in proteid combination and 40 per. centiin 
non-proteid combination we may calculate the nitrogen factor 
in the following manner: One gram of nitrogen may be con- 
sidered as representing .6 gram in proteid and .4 in non-pro- 
teid combination. /The proteids corresponding to the .6 gram 
of nitrogen would be found by multiplying .6 by 6.25 and would 
amount to 3.75 “rams. The .4 gram of non-proteid nitrogen 
may be assumed to exist in forms equivalent to asparagin 
containing 21 per cent. of nitrogen, corresponding to a protein 
factor of 4.7. This would give (.4 X 4.7 =) 1.88 grams of 
non-proteids. The 1 gram of nitrogen would thus correspond 
to*(3.75 + 1.88=) 5.63 grams of protein. For the present 
purpose we may assume that one gram of nitrogen in vegeta- 
bles corresponds to approximately 5.65 grams of protein. This 
makes the nitrogen factor 5.65. Ina similar way the factor 

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