NUTRITION LABORATORY. 221 



cultural Experiment Station, University of New Hampshire, have been 

 continued by Dr. Carpenter. Especial attention has been given to the rela- 

 tionships of three foi-ms of sulphur found in steers' urine, viz, inorganic and 

 ethereal sulphates and neutral sulphur, as affected by changes from fasting 

 to feeding and by various planes of nutrition. The daily urinary nitrogen 

 excretion of two steers for a period of 71 days has been determined and the 

 effect of storage upon the quantity of ammonia has been observed. The 

 analyses were done by Mr. Philip P. Saponaro. 



Reduction of potassium permanganate by urine. — Studies of transforma- 

 tions of energy in the animal body require a knowledge of the potential 

 energy of the urine in order to be complete. For a number of years the Nutri- 

 tion Laboratory has had the problem of finding some simple chemical deter- 

 mination for urine whose results would have a relation to the heat of combus- 

 tion of urine. During the past year the problem has been attacked by Dr. 

 Carpenter from the standpoint of the reduction of an oxidizing agent, viz, 

 potassium permanganate. An intensive study has been made of conditions 

 essential for consistent results in titrating urine with tenth-normal potassium- 

 permanganate solution, and the relations of this value to specific gravity, 

 total nitrogen, total solids, and organic matter have been found. The details 

 have been carried out by Mr. E. S. Mills. 



Temperature of the skin. — By means of the thermo-electric element and 

 special technique, skin temperatures of humans, both clothed and nude, were 

 observed in a large number of experiments. Special attention was given to 

 the rapidity of change in skin temperature when the skin is suddenly exposed 

 to cold. In many experiments temperatures taken deep in the body trunk 

 were recorded simultaneously with the surface temperature. 



Influence of environmental temperature upon metabolism. — In view of the 

 increasing importance of basal metabolism measurements in clinical medicine, 

 the exact conditions underlying the determination of basal metabolism need 

 closest inspection. The influence of environmental temperature plays a 

 significant role, and this factor has been studied under most diverse conditions 

 of temperature, clothing, and wind-velocity. 



The insensible perspiration of humans. — In continuance of previous in- 

 vestigations on the insensible perspiration of humans, observations were made 

 with a delicate balance and the rate of body-loss per hour was compared 

 in many instances with the metabolism measurements. The influence of 

 environmental temperature and clothing was a special feature of the investi- 

 gation. 



Development of a simple apparatus for determining gaseous metabolism. — 

 Mrs. Cornelia Golay Benedict worked for several months in developing a 

 new apparatus of extremely simple type for measuring accurately the oxygen 

 consumption of humans. A description of this apparatus, together with 

 the results of a research made with it, has been published and is subsequently 

 reviewed. 



The metabolism of steers as affected by environmental temperature. — With 

 the large respiration chamber at the Agricultural Experiment Station, Uni- 

 versity of New Hampshire, Professor E. G. Ritzman has cooperated in study- 

 ing the influence of marked temperature changes in the environment upon the 

 metabolism of large ruminants, specifically steers. The gas-analysis appa- 

 ratus of Dr. Carpenter and the technical skill of Mrs. L. A. Ritzman have 



