J. W. Capstick and T. B. Wood 259 



Experimental. 



The experiments described below were carried out in the large calori- 

 meter described by one of the writers (J. W. C.) in a previous number 

 of this Journal'. As the method of working is fully described in that 

 paper nothing need be said here as to the details of the manipulation. 



The exjjeriments were made on a Large White pedigree hog bred by 

 Mr K. J. J. Mackenzie on the Cambridge University Farm. The hog 

 was born on January 2(jth, 1921, and was castrated on April 1st. The 

 experiments began at the end of November when the hog was 10 months 

 old and continued to the following April. 



The food given to the hog was of the .same general character through- 

 out the experiments and was gradually increased so as to be roughly 

 proportional to the two-thirds power of his weight. As an indication of 

 the nature and amount of his food, he received when his weiffht was 



o 



300 lbs. the following daily ration in two meals : 



2 lbs. sharps, 2 lbs. barley meal, 



1^ lbs. bean meal, 1 lb. maize meal, 



1 lb. fish meal. 



In the intervals between the fasting periods, which lasted from four 

 to six days, he was kept in a small paddock in the open air with a shelter 

 of wattle hurdles. In severe weather he was put in a sty in the labora- 

 tory. As he stripped his paddock bare of vegetation very quickly he was 

 given a little green food each day. 



The care of the hog was in the hands of Capt. J. S. Morgan who kept 

 him in excellent condition throughout. The fact that the hog gained 

 157 lbs. in weight in the course of the experiments, which lasted 140 

 days, in spite of his being without food for about a quarter of that time, 

 is sufficient indication that the fasts had no ill-effect on his health. 



The hog was put in the calorimeter about 9 a.m. and remained 

 there in darkness and without food, usually for five days. Regular sup- 

 plies of water were introduced from outside. During this period readings 

 were taken whenever the galvanometer curve showed that he had been 

 asleep for a sufficiently long time to get rid of the effects of muscular 

 activity. From these readings the heat evolution was calculated. No 

 analyses were made of the excreta nor was the respiratory exchange 

 observed. 



After each fasting period he was given about a fortnight to recover 



1 This Journal, 11. 1921, 408. 



