G Dr. F. Auerbach on the Passage of 



ing ice. Becently, however, experiments have been made on 

 dielectric, diamagnetic, and electrolytic influences of such 

 surrounding liquids, which appeared to me in the present case 

 not to be neglected ; and an apparatus so constructed was 

 sufficient for two of the magnetizing forces which I used — a 

 Daniell and a Bunsen battery of five cells at the most. With 

 the third (the current of a Gramme machine driven by a 

 steam-engine), it is true that in most cases sensible thermal 

 effects still remained ; they were, however, small enough to 

 admit of elimination. The employment of such powerful 

 magnetizing forces may perhaps in general appear to be su- 

 perfluous, since it is usually assumed that iron would be mag- 

 netized to so-called saturation by much feebler forces. But I 

 should doubt whether in such cases it is actually attained ; it 

 is probably " nearly " reached*. Perhaps the molecular mag- 

 nets deviate, in the mean, only a fraction of a degree from the 

 axis of magnetization ; but just the influence of the still pos- 

 sible twist may, in reference to such questions as these here to 

 be examined, be material. 



With the arrangement adopted there was no fear of thermo- 

 * currents ; but it was necessary to reduce as much as possible 

 the intensity of the above-mentioned extra currents. The ne- 

 cessity .of this will not, perhaps, be at once obvious. In the 

 present investigation, however, lasting influences are in ques- 

 tion ; and from these those momentary phenomena must be 

 easily distinguishable. But, in the first place, it is for many 

 reasons desirable to be able to determine also these lasting in- 

 fluences immediately after the closing of the current, in order 

 that it may soon be opened again ; and, secondly, those extra 

 currents are any thing but momentary phenomena. I have 

 much rather found that here the phenomena known under 

 the name of after-effect play a great part. This is the more 

 disagreeable, as the still remaining temperature-influences 

 continue to operate according to the time occupied by the 

 radiation and conduction. I have, on this account, operated 

 throughout with iron wires, in which Villari's currents appear 

 far less intense than in rods. 



§ 4. It is a priori to be expected that the nature of the wire 

 (whether it consists of steel or iron, whether it is hard or soft, 

 &c.) will have some influence on the phenomena exhibited by 

 it, that a wire which has not yet been galvanically operated on 

 behaves differently from one through which, during a longer 

 or shorter time, currents have passed, or which has already 

 repeatedly undergone longitudinal or transverse magnetiza- 

 tion. But to this must be added an essential moment, con- 

 * Thus M. Beetz cautiously expresses himself. 



