146 Biochcmical Proceedings, Hygienic Congress [Sept. 



A consideration of the unknown factors in the ill-effects of bad 



Ventilation 



YANDELL HENDERSON 



The facts regarding Ventilation present an extraordinary contra- 

 diction. Fresh air, sunlight and dry cool climates exert a decidedly 

 beneficial effect upon health. Ill-ventilated dwellings decrease 

 vitality. In some persons under certain conditions even a few min- 

 utes in a crowded room may produce acute ill-effects. As to how 

 these effects are produced physiology has up to the present time 

 afforded no satisfactory explanation. The evidence is almost en- 

 tirely negative. The ill-effects of bad Ventilation can not be due 

 to lack of oxygen. It is probable that they are not due in any con- 

 siderable degree to excess of CO2. The idea that they are due to 

 some poisonous substance contained in the expired air has in recent 

 years been regarded as untenable. Recently this conception has been 

 revived in a novel form by the brilliant work of Rosenau. Even 

 Rosenau's investigations do not appear, however, to afford the Solu- 

 tion of this problem. The recent investigation of Hill in England 

 and of Flügge and his pupils in Germany makes it highly probable 

 that the effects of fresh or vitiated air are brought about not by a 

 direct action upon the lungs but indirectly through the skin. It 

 appears probable that the temperature and moisture of the air sur- 

 rounding the body are the essential Clements. 



According to the explanation to be suggested in this paper the 

 condition of the skin exerts a potent influence upon the lungs. This 

 may be in part a vaso-motor reflex acting upon the pulmonary circu- 

 lation. More probably it is a chemical or hormone influence upon 

 certain pulmonary processes. The evidence accumulated during 

 recent years indicates that the lungs are not mere passive organs 

 through which gases diffuse as through non-living membranes. 

 The investigations of Bohr, of Haidane and his co-workers and of 

 the recent Pikes Peak expedition all tend to indicate that the lungs 

 are the seat of vital activities of great importance to health. Thus 

 under certain conditions the lungs secrete oxygen into the blood, and 

 it appears that considerable oxidation may take place in the blood 

 during its passage through the pulmonary vessels. The evidence 



