8 Dr. F. Auerbach on the Passage of 



5. H = 3D; M=1D. Wire/ 2 . n = 106. The magneti- 

 zing current remained closed for an hour. 



w Q +w k = 1-7429 w+w k = 1-7326 M> + w fc = 1-7386 



(w t =0-5207); therefore S=-0'0068. 



Here, therefore, first a greater transient, secondly a perma- 

 nent diminution of the resistance took place, although there 

 was no demonstrable permanent magnetization. The tempo- 

 rary diminution becomes still greater, if in its calculation we 

 neglect the permanent — that is, in calculating the difference 

 10— w Q} keep in view only the initial iv Q . Then we have 



S 1= = -00084. 



6. H=5D; M = 1D; w = 106. Wire/ 2 . 

 w +w k =l-7366 w;+^=l-7139 w + w k =l'7299 



(w k =0'5210) ; therefore S= -00159. 

 Neglecting the permanent alteration, we get 

 S 1= = -00186. 



Here the temporary alteration of the resistance is still 

 greater, its value reaching nearly 2 per cent. But the per- 

 manent alteration is also greater than in the preceding case. 



Some series of experiments on unannealed iron wires ex- 

 hibit the same phenomena, only more feebly. On the con- 

 trary, with a thin unannealed steel wire the resistance dimi- 

 nished nearly 3 per cent, when H = 3B, M = 1D were chosen. 



Most of the experiments made before the improvement of 

 the electromagnet, however, show an increase of the resistance 

 with magnetization, and, indeed, a greater temporary and a 

 smaller residual increase. As, however, in them it is hardly 

 possible to separate the influence of the increase of tempera- 

 ture, I have, with the exception of a few apparently reliable 

 ones, made no use of those experiments. 



7. I will next mention two experiments with thin unan- 

 nealed iron wires, in which no alteration amounting to O0002 

 per unit of the resistance occurred. In both was H = 2D, 

 n=92 ; further, in one of them M = 3D, in the other M = 2B. 



8. Annealed iron wire/ 3 (<2 about = 0'6). H=1D; M = 3D; 

 7i = 92. The resistance of the conduction-wires is already de- 

 ducted. 



w =0*5213 w; = 0-5234 i0 O =O-5214 S= +00038. 



9. Experiment 8 several times repeated. 

 i0 O =O-5214 10=0-5232 i0 O =O-5214 8= +00035. 



