Apkil 30, 1915] 



SCIENCE 



629 



plished even under unfavorable conditions, 

 but as a matter of common experience we 

 find that the children in overheated school- 

 rooms and the workers in overheated fac- 

 tories are listless and inactive. 



Fig. 5. Eelation between Boom Temperature 

 and Average Crampton Value for all subjects at 

 end of day. 



Experiments are now under way in re- 

 gard to the influence of overheated rooms 

 upon susceptibility to respiratory disease 

 which promise to confirm the observations 

 of Leonard Hill as to the changes in the 

 mucous membranes which follow exposure 

 to hot and dry air, while we find that the 

 resistance of animals to artificial infection 

 is very definitely lowered by chill follow- 

 ing exposure to a hot atmosphere. 



As to the effect of stagnant breathed air, 

 contaminated by a group of subjects so as 

 to contain on an average from 20 to 60 

 parts of carbon dioxide per 10,000, our ob- 



servations are entirely negative, so far as 

 the physiological and psychological and effi- 

 ciency tests above mentioned are concerned. 

 So long as the room temperature was the 

 same it seemed to make not the slightest 



/fOOM CoMOir/OH 



Fig. 6. Eelation between Eoom Temperature 

 and Average Amount of Physical Work accom- 

 plished during the day, in summer and fall ex- 

 periments. 



difference to our subjects whether the air 

 in the chamber was stagnant or was re- 

 newed at the rate of 45 cubic feet per min- 

 ute per capita — except in one particular 

 respect to be discussed more fully below. 



It is perhaps not unnatural that these 

 results, like the similar results of earlier 

 investigators, should be popularly misin- 

 terpreted as meaning that ventilation of 

 any kind is a needless luxury. When the 

 first progress report of the commission was 

 discussed in a New York paper under the 

 headline, "Commission put its 0. K. on 



