Intelligence and Miscellaneous Articles^ 297 



Have I not also proved, that in the friction of two similar bodies, 

 effected in such a manner that one of them becomes more heated 

 than the other, there is an evolution of electricity, and the body which 

 becomes most heated receives the negative electricity ? It has even 

 been inferred from this, that in the friction of two dissimilar bodies, 

 that which disengages the most heat generally has a negative tend- 

 ency. All these facts show an intimatS relation between the pi'o- 

 duction of heat and that of electricity, which I have always regarded 

 as concomitant, and which may be of such a nature that one becomes 

 annulled by the increase of the other. There would therefore be 

 nothing surprising if, in changes of condition, the electrical effects 

 disappeared in presence of the calorific effects. 



The considerations which I have just put forward support the 

 chemical theory of the evolution of electricity in the pile ; a theory 

 which I have always maintained for more than thirty years, namely, 

 that contact alone could not evolve electricity, and that for this pur- 

 pose some molecular work is necessary. 



But if the evaporation of water or of a solution in a platinum cap- 

 sule at or below the temperature of ebullition furnishes no electricity, 

 this is no longer the case if a few drops of the liquid be projected by 

 means of a pipette into the capsule, when this is sufficiently heated 

 to render the evaporation immediate ; there is instantly a production 

 of electricity ; the vessel becomes negative to such a degree that the 

 effect may be observed without the employment of the condenser : 

 this effect is due to the friction of the water at the instant when it 

 becomes converted into vapour on the inner wall of the capsule, and 

 is of the same kind as that observed in Armstrong's experiment. 



The gases are electrical at the moment "when they are evolved 

 abundantly from a liquid ; hydrogen and ammonia take an excess of 

 negative electricity ; carbonic acid and oxygen an excess of positive 

 electricity : these effects are due, not to a chemical decomposition, 

 for then the results would be reversed, but to the friction of the 

 gases against the liquids. 



Must we not infer from this, that, by an effect of the same kind, 

 the oxygen and carbonic acid gases exhaled from the leaves of plants 

 carry positive electricity with them into the air? 



Second Part. On the Electrical Effects produced by the contact of 

 Earth and Water. — The electrical effects produced by the contact of 

 soils with fresh and salt waters have been observed successively 

 with plates of gold or platinum, and with the same plates covered 

 with powdered charcoal of sugar-candy, to retard, as far as possible, 

 the polarization produced when the circuit is closed, so as to be able 

 to measure the effects ; the charcoal then acts upon the gases depo- 

 sited by its absorbent power. A sine compass was placed in the 

 circuit. 



Numerous experiments made in the Jura, in Lorraine, in the 

 Nivernais, and on the sea-coasts of Belgium and France, have proved 

 that vegetable mould is always positive in its contact with fresh or 

 sea water ; that the electrical effects arc very slight between waters 

 and the adjacent soils when the latter are permeable to the waters ; 



