'220 



of hail. Hail, whether in summer or winter, is almost, if 

 not invariably, accompanied with lightning. In the presence 

 of these facts, it seems not unreasonable to consider the 

 formation of hail as essential to great electrical storms; 

 although, as has been pointed out by Professor Thomson, 

 very considerable electrical effects might be expected from 

 the negatively charged air on the surface of the earth being 

 drawn up into columns, and although, as the same 

 philosopher has observed, every shower of rain gives the 

 phenomena of a thunderstorm in miniature. The physical 

 action of insulators and electrics in mutual friction must 

 certainly produce very marked effects on the grand scale of 

 nature. If we suppose that the falling hail is electrified by the 

 air it meets, the electrification of the cloud into which the 

 hail falls might thus be constantly increased until the balance 

 between it and the inductively electrified earth is restored by 

 a flash of lightning. If the hail is negatively electrified 

 by the dry air with which it comes in contact, the latter 

 will float off charged with positive electricity, which may 

 account for the normal positive condition of the atmosphere 

 in serene weather, as well as the electrification of the upper 

 strata evidenced by the aurora borealis. The friction of 

 wind has been supposed by Herschel to contribute to the 

 intense electrification of the cloud which overhangs volcanoes 

 during eruption. 



Dr. Thomas Alcock read a Paper " On the Tongues of 

 Mollusca." [An abstract of this Paper will be found in the 

 report of the Microscopical Section, Proceedings No. 12.] 



Dr. Grace Calvert stated that one of the difficulties 

 which Dr. Alcock had encountered in his extensive and 

 laborious researches, namely, that of preserving his specimens 

 from putrefaction, would be overcome by the use of a saturated 

 solution of pure carbolic acid, taking care that a small excess 

 of this powerful antiseptic should also remain at the bottom of 



