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XI. Supplementary Researches on the Direction and Mode of Propagation 

 of the electric Force, and on the Source of electrical Development. By 

 George J. Knox, Esq., A. M., M. R. I. A. 



Read May 25th, 1840, 



XI AVING in my former paper* described some experiments which proved that 

 water and phosphorus convey a current of electricity through their substances, 

 while metals convey the current along their surface, and feeling anxious to 

 discover some general law regarding the direction of propagation in liquid and 

 solid bodies, I have continued the investigation to fluids ; not only those which 

 convey the feeble current of the voltaic pile, but to others which require the 

 high intensity of the electrical machine ; and although the experiments be few, 

 yet I think that they may be considered to be sufficient to establish the law 

 regarding fluids, that they convey through their substance in all directions alike ; 

 an opinion which one would be inclined to adopt previous to experiment, from 

 considering the difference between the nature of liquid and solid bodies, the one 

 having their particles chained down by powerful affinities, which no ordinary 

 electrical force can overcome, while the other, from the perfect mobility of their 

 particles, allow the electric state to be induced upon them with equal facility in 

 one direction as well as another. 



That there exists no regular law with regard to solids, appears from the 

 Researches of Dr. Faraday (XI. and XIV. Series), in which he shows, that the 

 lines of induction do not pass through metallic bodies (1221), (affording a corro- 

 borative proof to mine that they do not convey through their substance), while 

 several solid bodies, such as shell-lac, sulphur, &c. (1228, 1308, 1309, 1310), 

 allow the inductive force to pass through them with greater facility even than 

 air. 



• Tran. R. I. A., vol xix. p. 147 ; Phil. Mag. vol. xvi. p. 185. 

 VOL. XIX. 2 L 



