RICE AS FOOD. 



373 



the body material containing phosphorus takes place in ordinary Filipinos, as 

 shown by an increased excretion of phosphorus in the urine, during periods of 

 mental work and control periods, in which the subjects are left entirely to 

 themselves, the diet being the "same. With three prisoners (D, E, H) we divided 

 the entire period into three sub-periods, during which on the one hand the men 

 were either quiet, bj' themselves or, on the other hand, performed mental work. 

 It was very easy to obtain "mental rest," but much more difficult to secure 

 "mental work." The men were asked to study arithmetic or history, or to read 

 poems either in Tagalog, English, or Spanish, but it was almost impossible to 

 make them do this for more than two or three hours a day, and we are sure 

 that when we were not present there was very little work done. One experiment, 

 number 9, apparently gave a decidedly positive result; experiment number 15 was 

 practicallj' indecisive; and experiments numbered 12 and 1.3, which seemed to be 

 the most successful of all, apparently gave exactly the opposite result, if differ- 

 ences could be considered to be present at all. 



Table VIII shows the influence of mental work and mental rest on the 

 phosphorus excretion in the urine, so far as our experiments go. We do not 

 believe that any definite conclusion can be drawn from them. 



Table Vm. — Xitrogen and phosphoric anhydride exc^'etion in the urine during 

 periods of rest and mental work. 



Bxpei'iment 9, Prisoner D. 



Condition. 



Nitrogen, 



P,05. ! 



Rest 2 days _ _ _ __. 



Grams. 

 11.01 

 12. 96 

 11.41 



1 

 Grams. 

 1.42 



Mental work 2 days 1 ^ 



Rest2davs __ _ 



1.85 

 1.56 







Experiment 15, Prisoner H. 





Condition. 



Nitrogen. 



PsOr,. 



Rest 2 days _ 



Grains. 

 13.75 

 13.77 



Grams. 

 2.14 j 

 2.42 



Mental work 2 davs .__ 









Experiments 12-lS, Prisoner E. 



Condition. 



Nitrogen. 



P.O5. 



Rest 3 day.s: 



First day 



t?rams. 

 9.09 

 8.80 

 9.01 



S.66 

 8.41 

 9.13 



8.45 

 8.76 



Grams. 

 1.65 

 1.13 ' 

 0.91 



1 



1.08 

 0.98 

 1.28 ; 



1.29 

 1.25 



Second dav.. _ ..I. _ _ 



Third day 



Mental work 3 days: 

 First dav „_ 



.Second dav... 



Third dav 



Rest 2 days: 



First day. _ _ _. 



Second dav... 



1 



