IIO STORRS AGRICULTURAL EXPERIMENT STATION. 
In the third experiment the diet was considerably smaller in 
protein and energy than in the two preceding. ‘The subject, a 
chemist, was accustomed to rather less muscular labor than the 
person in the first experiment. He was also rather lighter in 
weight and the diet which he chose was smaller in both nutri- 
ents and energy. There was a slight gain of protein and loss 
of fat during the experiment, but on the whole the organism 
was very nearly in equilibrium in respect to both nitrogen and 
carbon. The fuel value of the material actually consumed in 
the body was larger than either of the two preceding experi- 
ments, though somewhat smaller than that in the fourth 
experiment under similar conditions. 
In the fourth experiment the subject was a physicist. He 
was taller than the subject of the third and heavier than either 
of the subjects in the preceding experiments. ‘The diet, which 
was of his own selection, as in the previous cases, was the 
smallest of all in protein, though it was very nearly the same 
in energy as that of the third experiment. Nevertheless, the 
figures indicate a slight gain rather than loss of protein during 
all of the periods of the experiment when there was no espec- 
lally large muscular activity, though there was constant loss 
of fat from the organism. In the period of muscular activity 
the loss of fat was very much larger, and there was apparently 
a slight loss rather than gain of protein in the organism as 
shown in tables 13 and 14, where allowance is made for a lag 
of 30 hours in the urine. The loss of carbon during the hard 
muscular work amounted to 148 grams per day. 
It has been stated above (p. 102), that in experiment No. 4 
six hours was allowed for the lag of the urine. ‘That this time 
was insufficient was also pointed out, and 30 hours was sug- 
gested as the more probable period of lag. ‘Tables 1 3 and 14 
give the nitrogen and carbon balance in this experiment, 
together with the calculated protein and energy, allowing for 
both 6 hours’ lag and 30 hours’ lag. It will be seen that the 
results are much more uniform under the latter supposition 
than under the former. ‘Thus when we allow 6 hours’ lag the 
protein consumed during the three periods of mental work, 
rest, and muscular work are 82, 78, and 88 grams per day, 
respectively, while with a 30 hours’ lag the corresponding 
values would be 79, 78, and 98 grams. 

