12 Additional Remarks on the 



of perfect solution ; 2d, In a state of beginning pre- 

 cipitation ; or 3d, Completely precipitated, and falling 

 in drops of rain. 



In the first instance, where the water is in a state 

 of perfect solution, the air is clear, dry, heavy, and 

 its powers of solution still active, though it already 

 contains a considerable portion of water. In the se- 

 cond, the air becomes moist, foggy, its powers of 

 solution are diminished, and it becomes lighter in 

 proportion as its water is deposited. It is a singular 

 and well-attested fact, that it never rains in the region 

 of Peru ; but that, during part of the year, the atmo- 

 sphere is constantly obscured with vapours, and the 

 whole country involved in what they call ganias^ or 

 thick fogs*. 



'&" 



It is not necessary to point out the causes which 

 thus dispose the air to deposit its dissolved water ; 

 nor to consider with what bodies air hath a stronger 

 affinity than vi^ith water ; neither to enquire how far 

 the electrical fluid is engaged in the process. It is 

 sufficient to observe, that so long as these causes 

 have a general action on the air, they diminish its 

 power of solution, and, when they operate for a con- 

 siderable proportion of the year, they produce a foggy 

 atmosphere, or a moist climate ; and that, when the 

 air retains its humidity in a perfect state of solution, 

 the climate is dry : consequently, that the moisture 

 or dryness of a climate do not so much depend upon 



• D'Ulloa's Voyage to South-America. Vol. 11. p. 67. 



