166 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



in proportion as the gas is a less good conductor of electric- 

 ity, and the effect is more considerable on that portion of the 

 discharge near the electrode than upon the rest of the col- 

 umn. The electric conductivity of the gas also diminishes, 

 owing to the action of the magnet, and by a quantity that 

 varies very notably with the nature of the gas, being so much 

 more considerable as the gas is a better conductor of electric- 

 ity. As the result of his later investigations, De la Rive finds 

 that when the magnet is presented to the gas influenced by 

 the electric discharge in such a way that the axis of the 

 magnet is not perpendicular, but parallel to the axis of the 

 discharge, and is, in fact, a continuation of the latter, then 

 all the preceding phenomena are reversed. Further experi- 

 ments showed that a special and peculiarly intense resistance, 

 having its seat at the issue from the negative electrode, is 

 that which is overcome by the intervention of the magnet. 

 The dimensions of the negative electrode notably influence 

 the dimensions of the aureola. 7 A, XL VII., 464. 



FORMATION OF MAGNETISM BY ELECTEIC CUERENTS. 



Some researches made by Beetz into the possibility of 

 communicating permanent magnetism to the iron deposited 

 by galvanic currents have an interesting bearing, not only 

 upon chemical, but also upon geological theories ; he states as 

 the result of investigations into the influence of the chemical 

 nature of the solution employed as an electrolyte, that the 

 iron deposited from solutions containing sal ammoniac is in 

 a peculiar manner susceptible to the reception of permanent 

 magnetism. If the deposition takes place under the influence 

 of a strong magnetism, avoiding injurious circumstances, 

 there arc formed from the sal-ammoniac solution strong 

 magnets of uniform structure, while from solutions havino* 

 no sal ammoniac magnets are formed whose structure is ir- 

 regular, and whose magnetic power is quite feeble. Pog- 

 gendorff Anhalen, CLIL, 494. 



THE INFLUENCE OF A MAGNET UPON THE GALVANIC AECH. 



Messrs. Delarie and Sarasin have published the result of 

 some experiments concerning the effects of magnetism on the 

 electric discharge through rarefied gas when the discharge 

 occurs in the prolongation of the axis of the magnet; vari- 



