o'2'2 Mr. E. H. Hall on the new Action of 



give numerical results for this metal. The main object in 

 using it was to determine the direction of the new effect 



therein, nickel being, next to iron and cobalt, the most strongly 

 magnetic substance. As already stated, this direction was 

 found to be opposite to that in iron. The action in nickel, 

 though not really measured, was seen to be very decided, and 

 may possibly prove to be as strong as that in iron. 



Tm. 



The action in this metal is very small, and has not been 

 measured with any accuracy. Its magnitude may be one 

 thirtieth of that of the action in gold. 



Xo other conductors have been tested in such a manner as 

 to warrant an expectation of detecting an action. 



In the following table the results obtained with the different 

 metals are brought together. Those obtained with very thin 

 strips will be marked thus (?), for reasons which must be evi- 

 dent to any one who has read the preceding pages: — 



MxV 



Metal plate. M. C. -g, ■ 



Gold, Ho. 6 ["Lard"] , 152xl0 lc M 



6400 £x tan 23 44 150X10 10 rrv1n , 



., 6400 „ ,,42 14 150X10 10 f iJi0XiU 



„ 6400 „ ,,49 28 154xl0 10 J 



„ No. 5 [soft or semicohes.] 6400 „ .,42 26 161 xlO 10 



„ „ 6330 „ „ 26 2 163X10 10 , 



„ 6440 „ ,,22 48 162xl0 lo} " 



„ 6440 „ „ 43 164xl0 10 



„ No.4["soft' ; ] 6480 „ ,,22 21 155xl0 10 



„ 6480 „ ,,26 25 155 x 10 10 [ 1 -« lf)9 



„ 6480 „ ,,42 16 154X10 10 "' 



„ 6480 „ „ 28 43 154xl0 10 



., No. 30 A [semicohes. ?] 6520 „ „ 48 38 123xl0 10 'l 



„ 6600 „ ,,3130 124 xlO 10 1 1250X10 9 



„ 6600 „ „ 40 39 128xl0 10 J 



B [semicohes.?] 6760 „ „ 68 139 X 10 10 \ 14ftn v lfl8 



„ 6760 ., ,,39 26 141xl0 10 ) iiUUX1U 



Silver, No. 10 6580 „ ,,49 17 114xl0 10 ] 1iArts , 1ng 



6580 „ ,,32 20 HSxlO 10 j iibUXiU 



„ [deposited] A 7120 „ ,,43 33 134xl0 10 | ,„ - - 9 



„ 7120 „ ,,19 32 137xl0 10 / ldooXlU ' 



B 6640 „ „ 47 39 1350xl0 9 ? 



Iron, C 6680 „ ,. 38 37 -127xl0 9 "I 19R . v108 



., „ 6680 „ ,,46 13-130 ji-^oXlU 



Platinum 6830 „ „ 66 2 4170x10° 



Nickel — effect large, possibly as strong as in iron. 

 Tin — effect probably much smaller than in platinum. 



This table enables us to arrange the metals so far examined, 

 excepting nickel, in order, with respect to the magnitude of 

 the action observed in them. Opposite each metal in the fol- 

 lowing list is placed a number representative of this magnitude. 

 In the case of gold this number is a quantity inversely pro- 



