14 THE ATMOSPHERE. 



are throwing off oxigen. So that these two great king- 

 doms of nature are mutually and constantly performing 

 these kind offices to promote the growth and prosperity 

 of each, while they prevent the destruction of both, and 

 of every living existence which animates, enriches, and 

 dignifies this lower creation. For carbonic acid is not 

 only essential to the growth of vegetables, but is certainly 

 and instantly fatal to animals, one full inhalation of which 

 produces death, unless a supply of oxigen is instantly 

 provided. The moment a person enters an atmosphere 

 of this gas, as has frequently occurred in wells, and the 

 fermenting vats of breweries and distilleries, he drops 

 lifeless, and past recovering, except the supply of vital air 

 is immediate. 



Carbonic acid is no less fatal to combustion than to 

 animal life. If a burning candle or coal be immersed 

 in it, every appearance of combustion is instantly de- 

 stroyed ; but it may be again relighted, by letting it into 

 a vessel filled with pure oxigen. 



The sparkling appearance and agreeable taste of the 

 best cider, beer, wine, and soda water, are produced by 

 this active substance. By the loss of it, they become 

 dead, as we say, and are not only unpleasant to the taste, 

 but injurious to health. So that the same substance 

 which is distressing and fatal if taken into the lungs, 

 gratifies the taste and promotes health when received by 

 the stomach. 



By three classes of operations in nature and the arts, 

 carbonic acid is constantly formed, and oxigen destroyed. 

 These are respiration, combustion, and fermentation. 

 It has already been remarked, that the whole animal 

 kingdom are constantly consuming oxigen ; they are also 

 forming carbonic acid. The same double result is pro- 

 duced in most instances of combustion, and in every 

 instance of fermentation, in all its stages. It seems, then, 

 that the vital principle of the atmosphere is constantly 

 destroyed in vast quantities, and that a substance in- 

 stantly fatal, both to life and combustion, is constantly 

 forming, and yet the atmosphere continues to answer this 

 great purpose for which it was designed, and without a 

 sensible change in its character. 



