3 TO Analogy between Light and Eleftricity. [Book IV, 



eity, and moft inflammable fubflances are affc6ted by it 

 as by 'common fire, but in a weaker degree *. ythly. 

 The light emitted by the electrical apparatus has all 

 the properties of that which is emitted from the fun, 

 the compofition differing in fome refpects, according 

 to circumftances, as to the predominancy of certain 

 rays, the light in different inftances inclining to blue, 

 red, white, &c. according to its intenfity. Sthly. The 

 motion of light is exceedingly rapid, whether it is re- 

 flected or refracted ; in the fame manner the electric 

 fluid is found to move with almoft infinite velocity, for 

 it has been proved by experiments, that a cord twelve 

 hundred feet long has become inftantly electric in its 

 whole extent f. The Abbe Nollet has communicated 

 the electric mock to two hundred perfons at the fame 

 time, or at the lead perceptible inftant. 



Notwithstanding thefe confkkrations, it muft be 

 confefled that there are fome facts which feem to indi- 

 cate that the electric fluid is not purely and fimply the 

 matter of heat or light unmixed with other fubflances j 

 for i ft, we have obferved, that the electric matter has 

 the property of affecting the organs of fcent, which 

 belongs neither to light nor heat. 



2dly. It is well known alfo, that an accumulation of 

 the matter of fire or heat increafes the fluidity of all 



* Mr. Kinnerfley made a large cafe of bottles explode at once 

 through a fine iron wire; the wire at firft appeared red hot, and 

 then fell into drops, \vhich burned themfelves into the table and 

 floor, and cooled in a fpherical form like fmall fhot. Artificial 

 lightning, from a cafe of about thirty-five bottles, will entirely de- 

 ftroy brafs wire of one part in three hundred and thirty of an inch. 

 Metals may alfo be revived by the electric fhock ; and Slg. Bec- 

 caria melted borax and glafs by it. Prieftley'E Hift. Eledt. vi. 34; 

 r343- Seeds of clubmofs (lycopodium) were fired by itj alfa 

 aurujn fulminans, ib. 343. 



rf- Memoires de 1'Acad. des Sci. 1733, p. 247. 



bodies, 



