CHAP. 9. AND PRESSURE. 247 



We have usually a warm and agreeable sen- 

 sation of the atmosphere with such Rain, which 

 is strikingly contrasted to the cold and raw 

 sensation occasioned by the fall of thick wet 

 mists, or Rain which happens when, even with 

 a Northern or Easterly Wind, the Barometer and 

 Thermometer sink together, and when the air 

 has previously been found to be either nega- 

 tively, or nonelectrified. 



As far as we can determine, the air appears 

 capable of holding more water in solution, in 

 proportion as its temperature and pressure is 

 greater ; and yet the Thermometer often rises 

 when Rain is coming on, particularly in winter. 

 This circumstance is not wholly irreconcilable 

 with what has been laid down, since the Rain 

 may be occasioned by a diminution of pressure, 

 as is often manifestly the case, the Barometer 

 falling, or else by a supervening current of 

 colder or supersaturated air ; and the rise of 

 the Thermometer, which accompanies the fall of 

 the Barometer in this case, may be owing to the 

 increase of temperature produced by the con- 

 produces this smell the strongest ; and it is weakest with the 

 cold, and, perhaps, nonelectric Rain, which sometimes falls 

 after the condensation of a spreading sheet of cirrostratus into 

 nimbus, with a cold atmosphere. 



