222 



Mr. A. Tribe on the Distribution of 



[May 3, 



garding induced magnetism) upon the suspended needle ; then, as the line 

 joining the centres of the two magnets is in every part of the observation 

 approximately at right angles to the suspended needle, it follows from 

 (1) that the attraction of the bar will be proportional to its magnetism. 

 Hence in the north end downwards the equation of equilibrium will be 



c(M+T A t)=Xsin0, 



and with the north end upwards 



c(M— Y/i)=Xsin0\ 



Hence 2cY^=X(sin <p — sin 0'), 



2cM = X(sin + sin <p'). 



Hence T _sin0 — sin0'_tan i(<£— <f>') 



— sin + sin cf>' ~ tan J(0 + ' 



and since T = X tan i, 



M tan <p')_ sini* tan J(0— <p') 

 ^"taniX tan |(^ + 0')~2tan i tan J(0 + 0')' 



From the values of observations made at the Observatory with 66 

 magnets, all belonging to Classes A and B, we find — 





Mean value. 



Average difference 

 from mean. 



Maximum. 



Minimum. 





0-000207 



+ 0-000035 



0-000420 



0-000080 



III. " Distribution of the Radicals of Electrolytes upon an In- 

 sulated Metallic Conductor/'' By Alfred Tribe,, Lecturer 

 on Chemistry in Dulwich College. Communicated by Dr. 

 Gladstone, F.R.S. Received April 19, 1877. 



Among other facts demonstrated in my communication to the Royal 

 Society in January 1876 (Proc. Roy. Soc. vol. xxiv. p. 308), it was shown 

 that a rigid conductor, when placed lengthwise between the electrodes in 

 a fluid in the act of electrolysis, becomes, with sufficient battery-power, 

 endowed with the power of doing chemical work similar in kind to the 

 battery-electrodes themselves. This phenomenon, it was contended, was 

 explicable on the view which regards an electrolyte as a dielectric, with 

 the additional function of being capable of mutually exchanging its con- 

 stituents in the act of depolarization — a conception which induced the 

 quantitative experiments detailed below\ 



