THE ATMOSPHERE. 17 



habitants living upon the four quarters of the globe, a 

 portion of its genial influence. 



Every particle of the atmosphere contains a portion of 

 heat as well as moisture. To this substance, no less than 

 to water, it is the general and all powerful vehicle. It 

 is constantly transporting heat from the equator to the 

 poles, from land to sea, and from sea to land, from the 

 valley to the mountain, and from hill to hill. By this 

 office, performed by the air in these great operations 

 of nature, the heat upon the earth is in a measure 

 equalized. The deficiency in one country is supplied 

 from the excess of another. The intense cold of one 

 climate is softened by tempering the scorching heat of 

 another ; and by the equilibrium thus produced, both are 

 rendered productive of more life and more happiness. 



The connexion of the atmosphere with heat is the 

 source of every current and motion it receives, from the 

 gentle breeze to the raging hurricane. The theory and 

 the different kinds of winds, all of which are nothing 

 more nor less than the atmosphere in motion, and aJl 

 produced by the same cause, might seem to deserve a 

 full explanation in this place. But from the space 

 allotted to the present number, this subject must be de- 

 ferred to another. It is difficult in this connexion, how- 

 ever, to avoid the remark, that the expansibility of the at- 

 mosphere by heat, and its compressibility by cold and 

 pressure, are among its most remarkable and important 

 features, and distinguishes this and other airs from mat- 

 ter of every kind, either in a solid or liquid state. Air of 

 every kind appears to be capable of expansion and com- 

 pression to an indefinite degree. This property belongs 

 to each gas separate, and to several combined. 



In the manufactory of soda water, one hundred and 

 thirty gallons of carbonic acid is forced, by the means 

 of a condensing pump, into a cask, of the contents of ten 

 gallons, six of which are occupied by water. In the 

 fine syringe, the atmosphere is suddenly compressed into 

 so small a space, as to cause the oxigen it contains to 

 ignite a piece of cotton, previously prepared by moisten- 

 ing it with water highly charged with saltpetre, and then 

 thoroughly dried. When ninetynine hundredths of the 



VOL. i. NO. i. 2 * 



