THE ATMOSPHERE. 15 



Chemists have not yet discovered any other process, 

 by which this uniform and healthful state of the atmo- 

 sphere is preserved, but the reciprocal and mutual 

 action of the animal and vegetable kingdoms ; the 

 former, as has already been observed, by constantly con- 

 suming oxigen and producing carbonic acid, the latter 

 by taking up this substance so fatal to life, and giving in 

 exchange the ingredient which supports it. 



What a striking instance is this, of economy displayed 

 by the great Architect of the universe, in the work of 

 his material creation, and how much more striking and 

 wonderful is its fitness to answer the purposes to pro- 

 mote the ceaseless advancement of his intellectual and 

 moral creation, which constitutes the worth, the dignity, 

 and happiness of his boundless dominions. 



Carbonic acid is not only found in small quantities in 

 every part of the atmosphere, but is extensively diffused 

 through the mineral kingdom, especially in quarries and 

 mountains of limestone, every particle of which contains 

 a portion of it safely laid up for the use of the chemist 

 and artist, whenever he needs its use, or wishes to prove 

 its existence. 



Besides the air last mentioned as existing in the at- 

 mosphere at all times and in all places, several others 

 are occasionally found, and in some places they are con- 

 stantly forming in great abundance, among which is one 

 resembling the gas used for lighting cities. 



This gas is produced in large quantities in marshes, 

 masses of stagnant water, and in large cities, where a 

 due regard to cleanliness is not observed ; and is the 

 cause of sickness, and perhaps of malignant fevers. By 

 moving the earth in the bed of any pond, and even in 

 most streams of water, bubbles will be disengaged, and 

 rise to the surface, where they may be collected in bottles, 

 and by applying a lighted candle, they will be found to 

 be combustible. 



It is much lighter than common air, and consequently 

 rises into the higher regions of the atmosphere, where 

 it is frequently exploded by electricity, and is perhaps 

 the cause of shooting stars sometimes observed in the 

 heavens. 



