1892.] Electro-chemical Effects on Magnetising Iron. 



115 



The action of this salt 011 iron and steel is also very powerful, and 

 ensures freedom from the disturbing influences of violent effervescence. 

 Moreover, the results obtained with a copper solution of this nature 

 afforded an opportunity of simultaneously obtaining an indication of 

 the influence of magnetisation on the electrolytic deposition of copper 

 from its solutions on iron and steel. The investigation was conducted 

 as follows : the steel bars employed were of the lengths and diameters 

 given in Table I, each pair being cut adjacently from a long finely- 

 polished rod, so that the bars were as near as practicable alike in 

 general composition and structure. For every set of experiments one 

 of the steel bars was magnetised, the other being retained in its un- 

 magnetised state. The bars were each weighed on the balance, and 

 afterwards each bar was immersed in an equal quantity of cupric 

 chloride solution, in separate beakers, a considerable distance apart 

 (see fig. 1) ; the two beakers were of the same diameter and fluid 

 capacity ; the bars were placed in the beakers in the position shown 

 in fig. 1. On the completion of the periods of immersion stated in 



Fm. 1. 



Table I, each bar was taken out, and on removal from the solution 

 the electro-deposited copper was mostly found surrounding the steel 

 bar in the form of a compact hollow pipe or cylinder ; this was easily 

 drawn off from the remains of the steel bar, which formed a kind of 

 core within. The rods were carefully washed and cleansed from any 

 loosely adherent copper and carbonaceous deposit, dried, and then 

 weighed. A new pair of finely polished steel bars, one magnetised, 

 the other unmagnetised, was prepared in the above-named manner 

 for every experiment. The results obtained are stated in Table I. 



The cupric chloride solution was prepared as follows : 4 ounces of 

 crystallised cupric chloride were dissolved in 20 fluid ounces of water, 

 and each steel bar was immersed as previously described in an equal 

 quantity of this solution. A fresh solution of CuCl was prepared for 

 every set of observations, and the methods resorted to, with manipu- 



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