300 CARNEGIE INSTITUTION OF WASHINGTON. 



fitness of a series of diabetics at the Deaconess Hospital. Accompany- 

 ing these measurements were a number of psychological observations 

 in which the subjects were tested both in groups and individually, 

 for diabetics frequently complain of loss of memory and inability to 

 concentrate attention. The results are compared with like measure- 

 ments of normal subjects and also with those for the group of young 

 men in the large undernutrition study conducted by the Nutrition 

 Laboratory in 1917-18. 



Changes of muscle tonus with exposure to cold. — The changes in oxygen 

 consumption noted under different conditions of temperature environ- 

 ment might be accounted for by variations in muscle tonus. Dr. 

 Miles has cooperated in this phase of a research on temperature 

 environment and, by using the patellar reflex and certain other means, 

 has objectively recorded the changes in muscle tonus which occur when 

 the subject disrobes and sits in a cool room for 2 hours or so, during 

 which time measurements are made on the portable respiration appa- 

 ratus. 



The metabolism of young girls. — The series of observations on Girl 

 Scouts, referred to in previous reports, has been supplemented during 

 the past year by a study of two groups of Girl Scouts, one of 14 years 

 and one of 18 years of age. Special arrangements were made for secur- 

 ing the pulse-rate throughout the entire night by the attachment of a 

 stethoscope over the apex of the heart of each subject. The insensible 

 perspiration was most carefully recorded, as well as the basal metabo- 

 lism. This study supplements admirably the former year's work with 

 younger children. The research was carried out with the cooperation 

 of Miss Mary F. Hendry and Miss Marion L. Baker, and the extra- 

 ordinary cooperative spirit of the Massachusetts Girl Scouts made the 

 selection of groups of girls of these ages most satisfactory. 



Temperature of the skin. — One of the factors contributing to loss of 

 heat from the body is the relation of the temperature of the skin to the 

 environmental temperature. Studies on this subject were continued 

 with the special technique developed at the Laboratory, attention 

 being given primarily to observations in which a nude subject was 

 exposed to blasts of air from an electric fan at different velocities and 

 different environmental temperatures. The details of the measure- 

 ments were chiefly in the hands of Miss Alice Johnson and Miss 

 Marion L. Baker. 



Influence of environmental temperature upon metabolism. — This 

 research, which has been in progress for several years, was continued 

 with the same subject, special emphasis being laid upon the heat-losses 

 and the metabolism under different conditions of environmental 

 temperature and wind velocity. 



Radiation from the human body. — The great changes in skin-tempera- 

 ture with exposure to low environmental temperatures and the great 



