288 HISTORY OF 



so as to be intimately blended with it. It finds 

 a much easier admission into wine, or any fer- 

 mented liquor; and an easier still into spirits 

 of wine. Some salts suck up the air in such 

 quantities, that they are made sensibly heavier 

 thereby, and often are melted by its moisture. 

 In this manner, most bodies being found either 

 capable of receiving or affording it, we are not 

 to be surprised at those streams of air that are 

 continually fleeting round the globe. Minerals, 

 vegetables, and animals, contribute to increase 

 the current, and are sending off their constant 

 supplies. These, as they are differently affected 

 by cold or heat, by mixture or putrefaction, all 

 yield different quantities of air at different times ; 

 and the loudest tempests, and most rapid whirl- 

 winds, are formed from their united contribu- 

 tions. 



The sun is the principal instrument in rarify- 

 ing the juices of plants, so as to give an escape 

 to their imprisoned air ; it is also equally opera- 

 tive in promoting the putrefaction of animals. 

 Mineral exhalations are more frequently raised 

 by subterranean heat. The moon, the other 

 planets, the seasons, are all combined in produc- 

 ing these effects in a smaller degree. Mountains 

 give a direction to the courses of the air. Fires 

 carry a current of air along their body. Night 

 and day alternately chill and warm the earth, 

 and produce an alternate current of its vapours. 

 These, and many other causes, may be assigned 

 for the variety and the activity of the winds, 

 their continual change, and uncertain duration. 



