128 Notice of some Recent 



helix in a rag covered with mastic. The ends of the con- 

 ducting wire were soldered to the zinc and copper poles of 

 the battery; a single wire was employed. Aime, however, 

 considers that it may be preferable to unite several into a 

 bundle, or even to take a ribbon of copper covered with silk 

 or varnish. The bar ought not to be detached too quickly 

 from the horse-shoe ; it is necessary to wait until the in- 

 terior of the steel has acquired a slight elevation of temper- 

 ature, in order that the molecules may have time to arrange 

 themselves, conveniently, for magnetizing and tempering. 

 The duration of the immersion varies with the size of the 

 bar, and the temperature which it. possesses when taken 

 from the fire.* 



9. Magnetism by common electricity .-f — M. Llambias has 

 addressed a manuscript upon this subject to the French 

 academy. The results of his experiments were, 1. In 

 every metallic conductor traversed by the discharge of a 

 Leyden phial, two magneto-electric currents are simultane- 

 ously discharged, which pass in opposite directions, one of 

 which may be said to proceed from the vitreous to the 

 resinous pole, and the other from the resinous to the vitre- 

 ous pole. 2. The currents can be partly separated from 

 each other. This separation may be effected in dividing a 

 discharge between two or several different branches of the 

 same circle, when in some particular branch there is an in- 

 terruption which gives origin to the spark. 3. This separa- 

 tion of currents is more or less practicable, and is com- 

 prised within certain limits, which can be nearly deter- 

 mined by experiments for each discharge, and for each of 

 the other elements which produce the phenomenon. 4. The 

 separation of these currents may take place in any portion of 

 the circle submitted to the discharge, at the same time that 

 the other parts of the same circle are traversed by currents 

 completely re-united. 5. In every circle, or every portion 

 of the circle, which the two currents traverse in union, it 

 is, in general, the current which passes from the vitreous 

 to the resinous pole, or the primitive current which has the 

 chief effect in communicating the magnetic influence. 6. 

 Each of the currents magnetizes so much the more strongly 

 in proportion, as it is separated or disengaged from the 



* Journal de C'himie. Medic, i. 370. t Ibid, i. 30. 



