Intelligence and Miscellaneous Articles. 35 



Energy,' adapting it to his peculiar ' f theory of two opposing 

 Powers ; " omitting all reference to work done by Force and intro- 

 ducing the principle of the " Persistence of Force," in the sense 

 that "the total amount of Force or Aggregative Power in the 

 universe is always a fixed quantity " — a notion which at one time 

 so much exercised the mind of the great Faraday. Even " elec- 

 trical units " when free are described as " rushing at once iuto a 

 state of aggregation with their fellows " ! A notice of this book 

 should not conclude without mention of the perfect modesty — nay 

 "timidity" — with which it is offered to the public. "If I am 

 wrong," Mr. Allen assures us, " I shall expect to be frankly told 

 so : I shall accept demonstrations of my mistakes and misconcep- 

 tions with a good grace." .But ingenuously, though illogically, he 

 adds : " Naturally I shall continue still to think myself right." 

 To demonstrate, however, to Mr. Allen's conviction the errors of 

 his theory would involve his submitting himself to a strict, if not 

 an extensive, course of training in orthodox dynamical science, 

 which being mastered the scales would at once fall from his eyes, 

 even if he should be forced to exclaim " Pol, me occidistis, amici, 

 Non servastis .... cui sic extorta voluptas, Et demptus per vim 

 mentis gratissimus error !" — J. J. Walker. 



XLII. Intelligence and Miscellaneous Articles. 



ON THE DEPENDENCE OF THE ELECTROMOTIVE POSITION OF 



PALLADIUM ON THE QUANTITY OF HYDROGEN IT CONTAINS. 



B¥ MAX THOMA. 

 r PHE difference of potential of palladium wires charged with hy- 

 -*- drogen, in dilute sulphuric acid, against zinc was determined by 

 comparing the deflexions of a Wiedemann's galvanometer of 12,000 

 ohms' resistance, as well as a Mascart's electrometer, with that of 

 a Daniell's element E = l*07 volt. The metals were placed in 

 glasses, which were connected with a third one between them filled 

 with dilute sulphuric acid. 



The charge with hydrogen was defined by the expansion of a 

 palladium wire. The wire, along with the wire which served as 

 anode, was passed through a cork into a glass tube, and was bent 

 below into a loop and held by a glass rod. A thin copper wire 

 was attached to the palladium wire, which passed over a pulley and 

 was loaded with a kilogramme. A mark showed the elongation. 



The electromotive force of palladium towards zinc, so long as all 

 hydrogen is absorbed by it, is independent of the absolute quantity 

 of hydrogen (0*65). Palladium-hydrogenium is formed. If in this 

 way the palladium has been entirely changed into the latter, on 

 further charging with increase of hydrogen it continually ap- 

 proaches zinc, but still remains electronegative towards it. It 

 reaches the power 0*39 D. After opening the polarizing current 

 the polarization of the supersaturated palladium rapidly diminishes ; 

 and after a minute, even when the circuit was not closed, to the 

 values of (0-65-0*67) of the supersaturation. — Zeitsclirift fur jphysilc 

 CJiem. vol. iii. p. 69 (1889) • Beibldtter der Physi7c, vol. xiii. p. 529. 



