10 THE WOODLANDS. 



But when we come to the road from Arang, which 

 runs for about ninety miles through a barren treeless 

 plain, cholera appears every year in its worst form, 

 the dead and dying lying by the wayside, and trains 

 of vehicles, half of whose conductors are dead. 

 Similar testimony is given by medical officers of 

 barracks surrounded by trees, in which the inmates 

 were almost exempt from sickness, whilst in those ex- 

 posed to the full influence of the wind, without any 

 trees, cholera was prevalent. Dr. Bryden states that 

 in the villages of the almost treeless district of Raj poor 

 sixty or seventy per cent, of the inhabitants are some- 

 times swept away by cholera in three or four days, 

 while the wooded district of Sambalpoor is often free 

 from it, or it is not there severe. These facts, it is true, 

 "relate to a tropical country, remote from home, but they 

 serve to illustrate the theory here advanced that the 

 presence of trees is important to the well-being of 

 man, and that the destruction of forests is in many 

 ways detrimental. 



In connection with this subject it may be remarked 

 that Ebermeyer has shown that the " temperature of 

 the trees in a forest, and even in the tops of them, is 

 always lower than the air in the forest. The shade of 

 a single tree, therefore, cools, not only by intercepting 

 the sun's rays, but also by the effect of gentle fan- 

 ning. The shelter of a thick wood, however, is much 

 more agreeable than that of a single tree. The air in 

 a wood is cooler than that of an open space exposed 

 to the sun. The air from outside is drawn into the 

 wood, is cooled by it, and cools us again. And it is 

 not only the air that cools us, but the trees them- 



