NATURE DOES THE WORK. 49 



which within the sultry region of the tropics sweep and 



cleanse 



' ' The swampy fens, 

 Where putrefaction in life ferments 

 And breathes destructive myriads ; " 



or nearer home, within the temperate zone, the cold " north 

 east," and those circling waves of air, the rough and noisy 

 Boreas and the " ever fanning breeze " or soft warm zephyr 

 of a summer day, constitute Nature's grand system of 

 ventilation, without which the fair world would be a 

 pestilential waste. 



By arresting the natural circulation of the air within the 

 walls of rooms, by artificial heat, by exhalations from the 

 lungs and body, by fumes from burning gas or oil, by subtle 

 poisons escaping from the sewers and other sources of 

 impurity, we repudiate the immutable laws of Nature, and 

 are punished by enfeebled health, disease, and death. 



It is evident we cannot do better than render the interior 

 of houses and public buildings as healthy, so far as purity of 

 the air is concerned, as the open fields. Is this possible ? 

 This is a question which Robert Boyle answered for us in 

 the affirmative. 



The inventor knew perfectly well that if people could 

 be persuaded to have appliances for the extraction of the 



hot, poisoned air from their houses, they would never 



D 



