Intelligence and Miscellaneous Articles. 75 



the region of the fixed stars, its locus being (within the limits of 

 probable error) the same as that of a Centauri. 



12. The accordance of the terminal locus -with that of a Cen- 

 tauri may he exact ; it is almost impossible that the deviation from 

 precise accordance can be so great as 8 per cent. ; and such a devia- 

 tion could be easily explained by stellar orbital motions. 



13. The second stellar abscissa, A^, indicates a distance corre- 

 sponding to Bessel's estimate of the parallax of 61 Cygni. 



14. "Whatever may be thought of the last three indications, the 

 first ten are clear, unmistakable, and incontrovertible. 



Haverford College, Nov. 15, 1881. 



ON THE ACTION OF COLD UPON THE GALVANIC AEC. 

 BY D. T03DIASI. 



"When the galvanic arc springs between two metallic rheophores, 

 of copper for instance, formed each of a tube bent in the shape of 

 a U, through which a rapid stream of cold water flows, and placed 

 horizontally one opposite to the other, the following facts are 

 observed : — 



(1) The iUuminating-power of the arc is considerably weakened : 

 it is reduced, so to say, to a mere luminous point, even when a 

 very intense electric current is employed (50-75 Bunsen elements, 

 large size). 



(2) The arc, if it can be called so, is very unstable ; the slightest 

 breath suffices to extinguish it*. 



(3) If a sheet of paper be placed over the arc, at a distance of 

 4 or 5 millim ., after a few moments a black point is seen to be 

 produced, which extends and is at last perforated ; but the paper 

 does not take fire. 



(4) The arc is constituted by a luminous globule moving up and 

 down between the two rheophores. The form of this globule, as 

 well as its extreme mobility, causes it to resemble very much a 

 drop of liquid in the spheroidal state. 



(5) If the south pole of a magnetized bar be brought near to the 

 galvanic arc, the arc is attracted and approaches the magnet so that 

 at length it leaves the rheophores and is extinguished. The same 

 phenomenon is observed, but in a contrary direction, on bringing 

 the north pole of a magnet towards the arc. 



(6) The amount of ozone seems to be greater than when the arc 

 is not cooled. 



It is to be remarked that, in spite of the cooling of the rheo- 

 phores, the flame of the arc is slightly green, proving that a portion 

 of the copper burns. Hence one is entitled to ask if the arc would 

 be produced by taking as rheophores two platinum tubes in which 

 alcohol cooled to 30° C, for example, was caused to circulate. — 

 Comptes Rendus de VAcacUmie des Sciences, Kov. 7, 18S1, t. xciii. 

 p. 716. 



* The instability is such that it cannot ignite a match without being 

 extinguished itself. 



