PHYSIOLOGY: F. G. BENEDICT 
229 
food and drink other than distilled water, and finally a three-day reah- 
mentation period. In all save the last period the experiment was most 
successful. 
Measurements were made of the body-weight, insensible perspiration, 
rectal temperature fluctuations, pulse-rate, blood pressure, and the 
morphology of the blood. The mechanics of respiration and the alveolar 
air tension were also observed. A complete clinical examination was 
made every second day with a record of subjective impressions and 
psycho-physiological observations. The intestinal flora were studied 
and the skin excretion determined. A complete chemical examination 
was also made of the urine, including the partition of the nitrogen and 
the determinations of the chlorine, phosphorus, sulphur, total acidity, 
and B-oxybutyric acid. The mineral constituents, particularly the cal- 
cium, magnesium, sodium, and potassium excretion, were studied and 
the reducing power, the carbon, and the energy of the urine were de- 
termined. Throughout the fast the urine was examined daily with a 
microscope and tested for albumin. Of special significance was the 
study of the respiratory exchange, both with the universal respiration 
apparatus and with the large bed respiration calorimeter. 
In the respiration calorimeter it was possible to measure simultane- 
ously the carbon-dioxide excretion, the oxygen consumption, and the 
water vaporized from the lungs and skin. Direct heat measurements 
were Kkewise made which, when corrected for body temperature fluctua- 
tions, gave the exact heat production. From the results obtained with 
the respiration apparatus the effect of various factors upon the metabo- 
lism was studied, such as changes in the body position, the work of writ- 
ing, and breathing oxygen-rich atmospheres. The metaboHsm of the 
subject during sleep was also compared with his metabolism in the 
waking condition. The energy transformation per kilogram of body 
weight and per square meter of body surface was computed. From the 
numerous respiration experiments with both apparatus and a careful 
record of daily activity, the total balance of income and outgo for this 
man for the thirty-one days could be computed with great accuracy. 
Of special clinical importance are the records of the losses in Aveight; 
the studies of the rectal temperature, blood pressure and blood; the acid- 
osis induced by the fast; and the effect of the fasting upon the composi- 
tion of the urine and the respiratory exchange. The psychological stud- 
ies and the general observations of the man showed that for thirty-one 
days the subject was able to exist in a fairly normal mental condition, 
entirely out of proportion to the physical dechne in the body functions. 
The ill-advised insistence of the subject led to his breaking the fast by 
