228 Intelligence and Miscellaneous Articles. 



Lines. 



0-010 millim. Eed. Blue. Violet. 



E 14 12-6 39-3 110-9 



E 10 17-8 55-0 133-8 



E 6 38-5 94-9 176-4 



E 2 76-1 183-2 289-6 



The curves traced by means of these values show the inequality 

 of intensity of the three lines, an inequality variable with the 

 induced discharge. In proportion as the pressure diminishes, the 

 ordinates are augmented considerably, and the curve rises through- 

 out. For the pressure of 6-5 millim. the curve of the red line 

 becomes a straight line. 



In the various conditions in which I have operated, I have been 

 able to make a pretty large number of observations on the influence 

 of impurities, the nature of the stratifications, and the production 

 of the sensitive state* in rarefied tubes. I am continuing these 

 experiments, measuring the difference of potentials at. the two ex- 

 tremities of the tube and illuminating the tube by the discharge of 

 the IToltz machine. 



It would be premature to draw any definitive conclusions from 

 the present results ; I wished, in this first note, to confine myself 

 to indicating the first results of the investigation and showing the 

 general course of the phenomenon. — Comptes Rendus de VAcademie 

 des Sciences, Dec. 26, 1882, t. xcv. pp. 1350-1352. 



CENTRAL FOBCES AND THE CONSERVATION OF ENERGY. 



To the Editors of the Philosophical Magazine and Journal . 

 Gentlemen, 



If your correspondent, Mr. von Tunzelmann, will refer again to 

 my paper, he will see that his criticism in your February number 

 is not justified. I had at the outset (p. 35) assumed F to be the 

 component of the moving force in the line joining the two particles 

 considered ; and it was subsequently shown (p. 38) that if there 

 were any component at right angles to that line, the conservation 

 of energy would not hold. The argument on p. 37 is therefore 

 perfectly legitimate, Walter E. Beowne. 



Erratum. 



In the footnote to Prof. Silvanus Thompson's paper in our last 

 Number, p. 124, it was stated by inadvertence that it was commu- 

 nicated by the Physical Society. It should have read communicated 

 by the Author; the paper, however, was subsequently communi- 

 cated to the Physical Society. 



* W. Spottiswoode and Moulton, Philosophical Transactions, 1879. 

 •p. 165. 



