2^58 IXFIX'KXCK OF COOLIXU POWKIIS OF ATMOSPIIEUE. 



the weather was cool owing to rains. The daily cooling power 

 of the atnicjisphere averaged. 5".3 units dry kata at noon. The 

 average da,ily consumption by the animal under observation was 

 239"5 grammes of nulk and 45"4 grammes of oats and bran. 

 From the 15th to the 24th (jf February the weather was hot, the 

 coolLng power averaging 3*7 units dry kata at noon. The animal 

 consumed on an average 116 grammes of milk and 40"9 grammeo 

 of oats and bran. Apart from the variations in the atmosphere, 

 these animals were kept under uniform conditions. The nature 

 of the diet was constant. Further, one may assume that these 

 lowly animals are not much influenced by affective states, plea- 

 surable or otherwise. Since the animals were not stimulated to 

 eat more because of increased tastiness of the food, nor less 

 because of depressed mental conditions as might occur in human 

 beings, one appears to be justified in assuming that the amount 

 eaten is a direct criterion of the metabolic activity of the animal. 

 Under these circumstances the onlj' stimulus for increasing eating 

 rt'ould be increased tissue hunger. 



Hill and Campbell showed the stimulating effect of high 

 cooling powere on the metabolism of children exposed more or 

 less nude to the conditions obtaining during the Alpine winter.* 

 This influence on the meta,bolism would be expected to reveal 

 itself in an increased rate of growth of infants in cool weather. 

 The summer of the Transvaal contrasts markedly with the 

 winter, and as the latter is seldom excessively cold, a comparison 

 of the rate of growth of infants in the two seasons should reveal 

 whether or not growth of infa,nts is more rapid diu-ing a season 

 of comparntively high atmospheric cooling power. 



At the Infant Clinic conducted by the Municipal Council of 

 Johannesburg the infants are systematically weighed. The records 

 of nineteen normal infants under one year in age were tabulated 

 as shown in Table II, the increase in weight dvu'ing the summer 

 months. October to March, being compared with that during the 

 winter months, April to September. It is seen that for these 

 infants the average monthly increase in weight was 0"79 pounds 

 in summer and 1"46 pounds in winter. These infants all came 

 from the poorei" quartei^s of the town, where it is probable that 

 exposure to cooling is greater than in the more comfortable homes 

 of the wealthy. This has an important clinical bearing. It would 

 appear that in Johannesburg the conditions to which infants are 

 normall}^ exposed in summer are not ideally suited for growth. 

 The growth impulse is hampered by the warm sumixier condi- 

 tions, being much more effective under the cooler winter condi- 

 tions. In Johannesburg, and more so in towns such as TiOureneo 

 Marques, which have very warm summem, every effort should 

 be made to expose the infants to high cooling powers, if ideal 

 conditions for the growth impulse are to be obtained. The 

 minimum of clothing, the maximum ventilation of buildings, and 

 outdoor sleeping are of extreme importance. 



