©N ATMOSPHERIC PHENOMENA. JO? 



it is sufficiently concentrated to assume the requisite elas- 

 ticity, and then it is in the state of light. Light, though 

 little concentrated, produces this effect, because it has only 

 to lose a little of its elasticity to become electricity, or sub- 

 electricity, the fourth modification of calorie; which excess 

 of elasticity it transmits however to the caloric, with which 

 the bases abovementioiied are fixed, and which has lost 

 much of its natural elasticity in that fixation. Thus more 

 or less elasticity constitutes all the difference between light, 

 the electric fluid, sublight, and subelectricity, if indeed 

 this exist, and heat. We cannot take a single step in na- Their ready"* 

 tural philosophy or chemistry, without perceiving the faci- ^"h^^erthe 

 lity with which the>e agents are metamorphosed one into cause .f many 

 another; a metamorphosis on which depends a very great p " enoaieua " 

 number of phenomena. 



It is the heat alone that separates in great abundance, Heat partway 



and in a distinct part of the atmosphere, which can thus ail ° C 'V* mt ? 



r . l . separated only 



transform itself into electric fluid. That which is produced becomes eleo 



by the general loosening \re achemetit] of the air, or a cer- tnt &¥' 



tain de> omposition of this fluid in its aqueous combination, 



and which heats the atmosphere, has no occasion to diffuse 



itself, being generally separated, and it remains heat. Every Heat of the 



increase or diminution of the temperature ot the air is ai r »otcomnnK 



, . -. i i , t nicatedbut 



spontaneous, and not communicated, or conducted by the spontaneous. 



winds, which are themselves the eflects, and not the causes, 



of changes of temperature, and other alterations that take 



place in the atmosphere. 



At every increase of the temperature of the air, the baro- With the rise 



meter sinks, because the precipitation of water diminishes of tlie lilerma " 



v . .... , metei the ba- 



the elasticity of this fluid: as every diminution of temper- rometer falls, 



ature, which always results from the combination of water and vice versa » 

 with air, with fixation of caloric, and the transformation of 

 heat into electricity, causes the barometer to rise by the in- 

 crease of elasticity which the air acquires. This last effect 

 frequently takes place during rain, when this rain is the 

 •xcess of water which the air deposits, to be enabled to re- 

 sume, constantly under the influence of some sidereal 

 cause, that state of serenity, which constitutes fair weather. 

 This rain, or that which fails with a rising of the barometer 

 and a falling of the thermometer, is a rain of recomposition 



of 



