292 HUMAN PHYSIOLOGY 



the air chemically but it favors the removal of heat from 

 the bodies of the inmates and braces up their vasomotor 

 systems. An English writer, adopting a novel but sug- 

 gestive point of view, has said the real difficulty with a 

 stuffy room is that there is a lack of stimulation for the 

 nervous system. One becomes relaxed and indolent 

 because the receptors are not being played upon as they 

 would be by a breeze or even by a decidedly chilling 

 air. This is consistent with the recognized fact that the 

 most comfortable climates do not make for the greatest 

 efficiency. 



We may ask in passing what are the causes of death 

 when people are huddled in narrow quarters. The classic 

 illustration is that of the Black Hole of Calcutta. About 

 150 English soldiers were confined through a tropic night 

 in a room 20 feet square. There were but two windows, 

 both on the same side of the room. Only twenty-three 

 men survived. Perhaps in a case as extreme as this 

 actual shortage of oxygen and damaging excess of carbon 

 dioxid might have been realized. There might also have 

 been definite poisoning from volatile excretions. But 

 another factor which we cannot overlook must have been 

 the collective rise of temperature resulting from the 

 crowding together of so many bodies. This was made 

 more acute by the struggle which went on among the 

 agonized prisoners. 



