PHYSICAL PROBLEMS WHICH ARISE IN STUDYING THE 

 INFLUENCE OF ATMOSPHERIC CONDITIONS UPON 



HEALTH 



By a. Norman Shaw, D.Sc. 



(Presented by Dr. A. S. Eve, C.B.E., F.R.S., F.R.S.C.) 

 (Read May Meeting, 1920.) 



This article is written in order to plead for an increased interest and 

 for a larger number of workers in the subject under discussion. The 

 field of investigation has, indeed, such an important bearing on the 

 health of the community, it contains so many unsolved but yet not too 

 formidable problems, and there have remained almost undisturbed in 

 the customary treatments of the matter, so many fallacies that it was 

 considered of importance to call further attention to the whole question, 

 to enumerate some of the simpler problems, and to discuss briefly a few 

 of the difficulties which have been responsible for lack of progress in the 

 past. 



The study of the atmospheric conditions which determine human 

 health and comfort, involves physiological, bacteriological, chemical 

 and physical problems. The most general and practically inclusive 

 physical problem which arises, is to determine the influence of variable 

 surroundings upon the loss of energy from a heated thermo-regulating 

 mechanism which possesses an outer hygroscopic surface of variable 

 quality. It is thus closely allied to many other familiar problems which 

 involve questions of radiation, convection, conduction and evaporation. 



The reactions of the different types of external changes on the internal 

 animal mechanism are varied in character; and it is very important to 

 note that the operation of the regulating mechanisms requires the 

 special stimulus of a certain amount of continuous variation in the exter- 

 nal conditions, without which the performance of their proper functions 

 seriously deteriorates. It is evident therefore that a part of the main 

 physical problem must be considered with reference to the physiological 

 processes which are involved in the internal thermo-regulation. The 

 influence of the chemical constitution of the air, and of the bacterial 

 content likewise must be considered in conjunction with physiological 

 data, but on the other hand although obviously affected by the physical 

 conditions, they may quite logically be considered and investigated as 



