CHAP. 2. 9. OP CLOUDS. 67 



two clouds in this case being more nearly of a 

 size when the communication of their electricities 

 took place, neither of them drew the other into 

 itself, while both, losing their electric state, 

 went on to become separate nimbi, and united 

 merely upon the principle of attraction by 

 which a nimbus is held compact. 



SECTION IX. 



Of what has been called Spontaneous Nimbifi- 

 cation. 



BY what has been said above, it appears that 

 the cause of such a union between two differently 

 electrified strata of cloud, is the humidity of the 

 interjacent atmosphere: and this humidity, it 

 seems, may take place either in consequence of 

 the dispersion of some cloud from a cessation of 

 the electric actions which keep it together in 

 a mass, or by a more general deposition of 

 haze from the oversaturated air. Either of 

 these causes, by affording a communication of 

 electricity between the differently electrified 

 clouds, might cause their union, and the pro- 

 duction of nimbus. I think this will explain 



F 2 



