4 86 Snow, [Book VII, 



cloud, where the electric matter has Been found by 

 experiment to be generally in equilibrium ; while very 

 little is di (charged from the edges, which are ufually 

 found to be electrified either pofitively or negatively. 



The wind has been fuppofed to have an effect in 

 producing rain, by driving the aqueous particles into 

 contact, and thus caufing them to unite into drops. 

 But, by experience, wind fecms to have the direct con- 

 trary influence, and frequently prevents rain. 



Befides rain, many other phenomena are produced 

 by the capacity which air has in different circumftances 

 pf taking up, fiifpending, and depofiting water; the 

 chief of thefe are fnow, hail, fogs, clouds, dew,, and 

 hoar froft. 



The cold of the higher regions of the atmofphere ' 

 js fometimes fo great, as to freeze the aqueous par- 

 tides which form clouds. If the particles become 

 frozen before they have had time to unite into drops, 

 many of the fmall icicles which are produced, uniting 

 together, and being connected only at a few points, 

 form fiocculent maifcs, which are called fnow. The 

 order and arrangement of the icicles is not always the 

 fame ; they vary greatly, and this produces the variety 

 which is obferved in fnow. It is remarkable, that 

 though fnow varies at different times, yet what falls 

 together is always the fame ; that is, the fnow which 

 falls at a particular time, confifts of flakes, which vary 

 only in fize, but are all formed of particles difpofed in 

 a fimilar manner. We are not fufficiently acquainted 

 with the laws by which the concretion or cryftalliza- 

 tion of bodies are regulated, to explain the caufe of 

 thefe phenomena. On account of the fmall quantity 

 pf matter contained in fnow, in proportion to the 

 furfaces expofed, it meets with great refiftance in 

 paffing through the atmofphere^ and confecjiienrly falls 

 * very. 



