34 
DIGESTION EXPERIMENTS. 
The object of conducting' the experiments here recorded was to 
gather data relative to the digestibility of fruit and nuts, not only for 
the purpose of ascertaining the quantities of nutriment utilized by the 
vegetarian and fruitarian, which is of course of great physiological 
interest, but also in order to learn whether fruit and nuts should be 
considered as sources of nourishment in any consideiable degree and 
not merely as luxuries or as articles of supposed hygienic or medical 
value. 
Thirty-one digestion experiments, which included also determina- 
tions of the nitrogen balance, were made with four different men. 
Two of them, W. S. M. and C. P. EL, subjects of dietary studies Nos. 
355 and 356, respectively, were upw 7 ard of 60 years old. They had 
been, as already noted, accustomed to the fruitarian and vegetarian diet 
for man) years. Subject C. P. H. was in excellent health throughout 
the entire experimental period. Subject W . S. M. complained at differ- 
ent times of numbness in the feet and lingers, which had been troubling 
him for several years." 
The other two men were university students in good health. J. E. R. , 
subject of dietaries Nos. 360, 361, and 362, was accustomed to a mixed 
diet and was placed on the fruitarian diet for purposes of comparison. 
A. V., the subject of dietary No. 363, had been experimenting with 
the fruitarian diet for several years. 
The usual method was followed in conducting these experiments, 
which, with two exceptions, lasted four days each. All the food eaten 
and the resulting urine and feces were carefully weighed and analyzed. 
The energy of the urine was computed by assuming that for every 
gram of protein in the digested material there would be 1.25 calories 
of energy lost in the organic matter of the urine. 6 The separation of 
the feces was made by means of charcoal, taken either in the form of 
compressed tablets or in gelatin capsules. It w r as somewhat difficult 
at times to make an accurate separation, but in the majority of the 
tests the line of demarcation between the feces colored by the char- 
coal and those not so marked was clear and distinct. In nineteen of 
the experiments the feces were examined for the so-called metabolic 
nitrogen. 
It was planned to make tests with single fruits and then combine 
them in succession with the different nuts ordinarily used, as it was 
thought that in this way the digestion coefficients of the different nuts 
alone could be obtained by making the usual calculations and that 
their comparative digestibility would also be shown. In all, ten 
a Six months after the conclusion of the experiment the subject became ill, and the 
physician diagnosed the case as ocomotor ataxia, which later terminated fatally. 
&U. S. Dept. Agr., Office of Experiment Stations Bui. 53, p. 27; Bui. 121, p 21. 
