4 '28 HYPOTHESIS OF TWO FLUIDS. 



centrated into a spark or ball of fire. Much 

 also remains to be done before the theory of the 

 voltaic pile is thoroughly understood. 



If, however, it be true, that all the forms and 

 modifications of this mysterious agent are con- 

 vertible into caloric, the theory of both will be 

 greatly simplified, and must shortly be reduced 

 to a very few fundamental axioms. 



I have proved from the most elaborate series 

 of experiments on record, performed by De 

 Saussure and Read, that all atmospheric elec- 

 tricity, even that of the most serene weather, is 

 disengaged from aqueous vapour and by the 

 experiments of Dal ton, that caloric is the true 

 and only cause of evaporation. There is also a 

 perpetual flux and reflux of the electric fluid, 

 corresponding with the diurnal variations of 

 temperature, and fluctuations of the barometer. 

 According to De Saussure, it diminishes from 

 9 or 10 o'clock m the morning until 5 or 6 

 p. M., and increases until 8, when it again de- 

 creases until sunrise, when it is almost null 

 that is, it is most abundant when the vapour of 

 the air is undergoing condensation, (for the 

 same reason that it is plus or positive during 

 the formation of clouds, and during rain or 

 snow ;) but diminishes during the heat of the 

 day, while the vapour of the air is undergoing 

 expansion, by which it is connected with the 

 whole theory of evaporation, condensation, and 



