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ANALYSIS OF THE GALVANIC VllZ. 



next to it. A negative body produces also an effect analo- 

 gous to a piece of ice : for as this absorb-; a part of the free 

 fire in the parts of the mass of air next to it; so the nega- 

 tive bovy absorbs a part of the vector f.om the electric Jiuid 

 on the nearest part of the conductor. Now, all these changes 

 in tne degree of expansive power in both fluids are attended 

 with inverse changes in their density. 

 This proved by Nobody will doubt of the above statement, who has re- 

 expenments p ea ted the experiments described in my works; and 1 may 

 say, that every one of the great number of persons, in whose 

 presence 1 have made these experiments, with the set of 

 small electric instruments described in my Traiteelementaire 

 svr ie Fluide Electro-galvanique, has been convinced of this 

 important distinction between the density and expansive 

 power of the electric jiuid. It is not therefore for want of 

 progress in the science itself, that such variety of systems 

 subsists concerning the electric phenomena ; it is for want of at- 

 tention, in most experimental philosophers, by whom, though 

 writing on electricity, my published experiments are never 

 mentioned, not so much as to criticise them, or their con- 

 clusions. Among the variety of these experiments, 1 have 

 here chosen those concerning the modifications which take 

 place on a long insulated conductor ; and I come now to 

 the particulars, which will prove all that I have stated 

 above. 



Three electroscopes are used in that series of experiments, 

 one of which, a movable one, coiiMsts of silver lamina, sus- 

 pended on small axes, in order to prevent their motion out 

 of the line of their divergence. Of the two other electro- 

 scopes, consisting of small pith balls suspended by silver 

 wires, one is permanently connected with the extremity of 

 the conductor farthest from the electrified body; the other, 

 held up at the top of a high insulating pillar, is kept, by 

 means of a thin wire, in constant communication with the 

 movable electroscope .- the latter, though principally destined 

 to move along the conductor, may be removed, from every 

 point, to a distance, in order to try the nature of the di- 

 vergence that it had at this point, which it does not lose on 

 removal. Lastly an insulated brass disk is the electrified 

 body. The following are the phenomena observed, in which 

 must be recollected what I undertake to prove, namely, 



that 



?nmts tolse 

 proved. 



