390 Intelligence and Miscellaneous Articles* 



houses, and considered it likely to be acted upon, as the paint was 

 rendered soluble by the acids contained in the atmosphere of towns. 

 — Chemical News, October 13, 1865. 



USE OF MAGNESIUM AS ELECTROMOTOR METAL IN VOLTATC 

 ELEMENTS. BY M. BULTINCK. 



Having observed the great oxidability of magnesium as compared 

 with other electromotor metals, I supposed it might be used advan- 

 tageously in place of a less oxidizable metal. I made the experi- 

 ment with a multiplier, taking as standard of comparison copper and 

 zinc in pure distilled water, and I have had the following result. 



Taking on the one hand two wires, one of zinc and the other of 

 copper, and connecting both with a multiplier, and then immersing 

 them simultaneously in distilled water, I obtained at the moment of 

 immersion a deflection of 30°, and after five minutes the needle 

 stopped at 10°. On the other hand, with two wires of magnesium 

 and silver respectively, and of absolutely the same dimensions as 

 those of the wires of copper and zinc, I obtained at the moment of 

 immersion a deflection of 90°, and after five minutes' immersion the 

 needle stopped at 28°, showing a difference of 60° in favour of mag- 

 nesium and silver over zinc and copper. 



This first result inspired the desire of having a voltaic element 

 with magnesium instead of zinc ; but as I had only a little of this 

 metal in the shape of fine wire, it was limited to making a voltaic 

 chain, which, spite of its smallness, has given surprising results. It 

 is constructed as follows : — 



It consists of three pieces — a small piece of caoutchouc 14 millims. 

 in length and 4 millims. broad by 3 millims. thick, a magnesium wire 

 35 millims. in length, and a silver wire of the same dimensions as 

 the magnesium wire. The magnesium and the silver wire are folded 

 upon themselves in two equal parts ; then each wire thus folded is 

 put astride one of the ends of the piece of caoutchouc, but so that 

 one (the magnesium, for instance) is across the breadth and the 

 other across the thickness, and that the part which forms the fold 

 projects sufficiently to serve as ring. The whole is well fixed by 

 means of a double knot of silk thread. 



Twenty such elements joined form the chain. As regards the 

 effects, by placing the chain in water without any addition of salt 

 or acid, all the effects possible with a Pulvermacher's chain are ob- 

 tained — the only difference being that Pulvermacher's chain must be 

 immersed in acidulated or saline water. By the use of magnesium 

 a galvanic current can thus be formed without the use of any acid 

 or salt. — Comptes Rendus, October 9, 1865. 



ON THE INVERSION OF THE SPECTRA OF METALLIC VAPOURS. 

 BY LOTHAR MEYER. 



The author describes the following simplified method of Madan's 

 experiment* for showing the inversion of the spectra of metallic 

 * Phil. Mag. S. 4. vol. xxix. p. 338. 



