On the Tlieory of Mixed Gases, 815 



hail, as Well as violent hurricanes. I do not 

 pretend to assign the refrigerating cause, or the 

 agent that produces precipitation in this case ; 

 I only have to observe, that the portion of air 

 must lose much of its elasticity, which is sud- 

 denly cooled to 70 or 72 degrees, and at the same 

 time parts with the water it held in solution. 

 This partial diminution of spring will destroy 

 the equilibrium of the adjacent parts of the 

 atmosphere, and may be supposed to produce 

 the tornadoes of the tropical regions. The 

 same cause probably gives rise to the fluc- 

 tuations of the barometer in milder climates : 

 for though the changes of temperature are less 

 n the milder than in the hottest parts of the 

 globe, the agents that precipitate the water of 

 the atmosphere, appear to act on a more ex- 

 tensive scale, and through a longer duration in 

 the former situations than they do in the latter. 

 Wet weather is neither momentary nor local in 

 Europe ; provinces, and even kingdoms are 

 deluged with rain for weeks together. The 

 air, which discharges such an abundance of 

 water will lose part of its spring, according to 

 Mr. Schmidt's experiments, even when it 

 suffers no change of temperature : now it is 

 evident that the equilibrium cannot be restored 

 in au instant ? because the diminished elasticity- 

 must be augmented *in this case by currents of 

 R r 



