Miscellaneous papers . since amagnet deflects thecathode rays, converselythe cathode rays mustdeflect the magnet. Butwhen we come to con-sider the expression amagnet deflects this orthat ray, and the com-parison thus set up withthe deflection of anelastic wire traversed bya current, we may welldoubt whether these areso suitably chosen as atfirst sight they appear FlG- 32>c (* nat size)- to be. Such a wire when the current starts would bestraight, and would only be brought into its deflectedposition after a finite time. But we know that cathoderays, even when the corresponding discharges las
Miscellaneous papers . since amagnet deflects thecathode rays, converselythe cathode rays mustdeflect the magnet. Butwhen we come to con-sider the expression amagnet deflects this orthat ray, and the com-parison thus set up withthe deflection of anelastic wire traversed bya current, we may welldoubt whether these areso suitably chosen as atfirst sight they appear FlG- 32>c (* nat size)- to be. Such a wire when the current starts would bestraight, and would only be brought into its deflectedposition after a finite time. But we know that cathoderays, even when the corresponding discharges last less than amillionth of a second, appear completely De laBives experiment in which the discharge is made to rotateabout a magnetic pole tells against the supposition thatelectromagnetic action can set gaseous discharges in motionwith such speed as this. In De la Bives experiment theaction is undoubtedly electromagnetic; but it takes place at a 1 See Goldstein, Vber eine Form der elektr. Abstossung, iii. 246 EXPERIMENTS ON THE CATHODE DISCHAEGE xm speed which is very easily measurable. And in every actualelectromagnetic effect the ponderable substratum of thecurrent is set in motion; which is not the case with thedeflection of the Hence this deflection correspondsmuch more nearly to Halls phenomenon. But this analogyagain is seen to be defective when we recollect that thecathode rays are not to be regarded as the path of the , it is known that the battery-discharge can be ex-tinguished by bringing a powerful magnet near it; and afterthe magnet is removed the discharge immediately starts off shows that the action of the magnet upon the dischargecannot be purely electromagnetic. The action of the magnet,which prevents the current from starting, certainly cannot bean action upon the current itself; it can only be an actionupon the medium through which the current has to pass. Onaccount of these difficulties, and the fact that the
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectphysics, bookyear1896
