ON THUNDER STORMS. /^IJ 



cal fluid, the doctor naturally concludes that thunder is the 

 sound caused by the discharge of a cloud containing an im- 

 mense quantity of electrical fluid accumulated together, and 

 says, " if two gun-barrels electrified, will strike at two inches 

 " asunder, and make a loud report, what would be the cflFect 

 " of perhaps ten thousand acres of electrified cloud." 



If the discharge of an electrified cloud were the sole cause Remark, that 

 of thunder, and the clouds were charged to so large an ex- thunder'is not 

 tent, it is probable that the effects would be much more tre- Si'idtyT 

 mendous, and that fatal accidents would more frequently occur 

 than they do at present ; but it appears almost impossible that 

 so large a quantity of the electrical fluid could be accumula- 

 ted, particularly after the first discharge, when the equilibriun^ 

 is restored, and the clouds, being full of wet vapour, are 

 consequently become good conductors. 



It seems more probable, that thunder is caused by the -but from the 

 explosion of hydrogenous and oxigenous gas fired by the elec- explosion of 

 trical fluid. It is well known that both these gases are ox'S" "' 

 constantly produced on the surface of the earth ; that stag- 

 nated ponds, swamps, &c. emit carbonated hydrogen ga^; 

 and that plants are continually decomposing the air of the 

 atmosphere, by imbibing the nitrogen, and emitting the oxi> 

 genous gas. This decomposition, and the formation of these 

 gases, goes on more rapidly in warm than in cold weather. 



On the commencement of a thunder storm, it is observ- Observations 

 able that the clouds are not very dark, but that after one "'' thunder 

 "I- two explosions they become very black, owing to the ''"'"''" 

 gases being converted into water: the rain then becomes 

 heavy, and small detached clouds fly towards the storm in 

 every direction, not, I imagine, by the attraction of the electri- 

 cul flmd, but to restore the equihbrium, and to fill up the 

 vacuum caused by the gases having exploded and formed wa- 

 ter and consequently occupying a much less space than they 

 d.d when in the state of gas. These clouds, by containing the 

 mixed gases, may serve to feed the storm, or the moisture in 

 them may become decomposed by the electrical fluid,* and 



« * " ^77" f-^^ ^^ ^vell as electrical fire, gives repulsion to 

 the particles of water, and destroys their attracdon of cohesion ; 

 hence eommon fire, as well us electrical fire, assists in raisni^ 

 vapours. -Iranklio's Works, vol. i. page 206. 

 Vol. XIV.-Supplemext, H h h niay 



