1046 
bination, the highly flavored fruit product 
whetting the appetite for the needed quan- 
tity of rather flavorless bread. 
Digestibility of Fruit 
In addition to the dietary studies, a 
large number of digestion experiments 
were made at the California Experiment 
Station for the purpose of learning how 
thoroughly a diet made up of various com- 
binations of fruits and nuts was as- 
similated. In such an experiment cover- 
ing ten days, made with a child seven 
years old, on an average 82 per cent of 
the protein, 87 per cent of the fat, 96 per 
cent of the nitrogen-free extract (sugar, 
starches, etc.), 80 per cent of the crude 
fiber, and 54 per cent of the ash of the 
food eaten were digested, and 87 per cent 
of the energy of the diet was available to 
the body. In 80 experiments with men, 
75 per cent of the protein, 86 per cent of 
the fat, 95 per cent of the nitrogen-free 
extract, 79 per cent of the crude fiber, 
and 55 per cent of the ash of the fruit 
and nut diet were digested, and 86 per 
cent of the energy was available. These 
values are comparable with those obtained 
from an ordinary mixed diet, as is shown 
by the fact that in 93 experiments with 
young men 93 per cent of the protein, 95 
per cent of the fat, and 98 per cent of the 
total carbohydrates supplied were assim- 
ilated. The average coefficients of digest- 
ibility which have been calculated for 
fruits in connection with the nutrition in- 
vestigations carried on under the auspices 
of the Office of Experiment Stations are 
protein 85 per cent, fat 90 per cent, and 
carbohydrates 90 per cent, and those for 
fresh vegetables, protein 83 per cent, fat 
90 per cent, and carbohydrates 95 per 
cent. 
The feces excreted per person per day 
on the fruit and nut diet in the California 
experiments were less in amount than 
has been the case in some experiments 
with a mixed diet or a ration of bread 
and milk. This is contrary to what has 
been commonly found with a vegetarian 
diet made up of bread and other cereal 
foods, garden vegetables, etc., and con- 
taining little if any fruit or nuts. The 
percentage of so-called metabolic nitrogen 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
in the feces from the fruit and nut diet 
did not exceed that reported by other in- 
vestigators in tests with a bread and milk 
diet. In other words, if the amount of 
metabolic products can be looked upon as 
a measure of the work of digestion, no 
more effort is required to digest the fruit 
and nuts than is needed for bread and 
milk. Although, as Professor Jaffa points 
out, itis undoubtedly advisable to wait un- 
til more data have been obtained before 
making definite statements regarding the 
digestibility of fruits and nuts, enough has 
been done to show that they are almost 
completely digested and have a higher 
nutritive value than is popularly attribut- 
ed to them. In view of this it is certain- 
ly an error to regard fruit as something 
of value only for its pleasant flavor or for 
its hygienic or medicinal properties, or to 
consider nuts simply as an accessory to 
an already hearty meal. As shown by the 
composition and digestibility of both fruit 
and nuts, they can be favorably compared 
with other and more common food. 
So far as can be learned, comparatively 
few investigations have been made to as- 
certain the digestibility of particular 
fruits, raw or cooked. In a series of in- 
vestigations by Bryant and Milner the di- 
gestibility of apple sauce was determined 
when eaten with a simple basal ration. 
The coefficients of digestibility for apple 
sauce alone were calculated in the usual 
way and were, protein 28 per cent, nitro- 
gen-free extract 99.6 per cent, crude fiber 
96 per cent, and ash 100 per cent, while 
all the energy supplied by the apple sauce 
was considered to be available to the body. 
The coefficient of digestibility of protein 
is low, but, as the authors pointed out, the 
total amount of this constituent present 
was so small that it may be disregarded. 
This investigation, like those at the Cali- 
fornia Experiment Station, indicates that 
the fruit carbohydrates (sugar, starches, 
etc.), that is, the principal nutritive ma- 
terials which fruits supply, are very 
thoroughly assimilated. 
Few studies seem to have been made to 
determine the ease or rapidity of digestion 
of different fruits in the stomach, but a 
comparison of available data indicates 
that fruits compare favorably with other 
