260 Banal Metabolism of Sivine 



before being put in the caloiimeter again. This proved to be long 

 enough to keep him in good health. 



The heat given off by the hog was measured in the usual way by 

 observing the rise of temperature of a stream of water circulating round 

 the calorimeter, additions being made for the latent heat of the water 

 vapour brought out in the ventilating air, for the sensible heat brought 

 away by the ventilating air and for leakage of heat through the walls 

 of the calorimeter. 



Details of the apparatus and the methods of measurement are given 

 in the paper quoted above. It is sufficient to say here that the rise of 

 temperature of the circulating water is measured by a thermoelectric 

 couple which traces a continuous record on a Cambridge and Paul Thread 

 Recording Galvanometer. This continuous record has proved to be a 

 very valuable feature of the apparatus. The writers consider that it has 

 enabled them to obtain more accurate measurements of the true Resting 

 Metabolism than have been obtained hitherto. 



The curve shows at a glance whether the hog is asleep or nul, how 

 long he has been asleep and whether his metabolism is rising or falling. 

 The slightest movement of the hog is recorded at once and the nature 

 of the hump on the curve often reveals its cause. An instance of this is 

 given in Fig. 1. 



Moreover there are occasional lapses in the apparatus. An electric 

 current may fail through a bad contact or other cause. The thermostat 

 may strike work through a heater burning out, dirty mercury causing 

 the relay to go out of action, etc. After some experience it has been 

 found that all these have their ch.iracteristic effects on the curve, so that 

 an observer watching the galvanometer can go at once to the source of 

 the trouble and remove it before any harm is done. 



In the earlier experiments the hog was very regular in his habits. 

 He seldom slept in the day-time but kept in continual motion, his 

 metabolism being very irregular and mounting gradually higher until 

 about 5.30 or 6 p.m. when he went to sleep, and usually did not stir 

 antil about 6 o'clock on the following morning, except that at some 

 time in the earlier part of the night he stood up to empty his bladder. 



Fig. 1 is the curve obtained on the second day of the experiment 

 which began on January 5. It has been chosen as showing several of the 

 characteristic features of these curves. The irregularity of the curve in 

 the day-time is much the same as is found in most of the curves, except 

 on the first day of the fast when the hog often slept a part of the day. 



The small hump at lO.oO p.m. is due to the hog's rising to empty 



