NO. 1863 BIBLIOGRAPHY OF CANAL RAYS — FULCIIER 307 



(i) Reflection of rays from electrode (see §3), and 

 (2) Secondary emission of cathode rays excited (see §9). 

 Nevertheless, Austin's work seems to be conclusive : Aui. 

 Failure to consider these effects may account for the follow^ing negative 

 results reported: An (327); Vi ; ¥3(16); Ln2(i8o) ; Bgi(692). 

 Some Negatively Charged, as shown by the direction of the magnetic 

 deflection: W5(262) ; Tm3(568) ; Tm8(67i). 

 Proportion of negative rays to whole is small: Wro(2i2). 

 Some Rays Uncharged for a portion of their path: Tm8(67o). 

 Current Carried by the Rays. 



Ratio of current flowing to earth from electrode, to total discharge cur- 

 rent, determined under varying conditions of pressure 

 and tension, in air, O2 and H2 : Ewi( 176-82), plate I; 

 Ln2(i98); cf. Pry (448). 

 Maximum current measured about io~' amp. : Ewi, plate I. 

 No correction for secondary emission: Fi(i53). 



Ratio reaches a maximum about at pressure when cathode ray fluo- 

 rescence begins: Pryl(448). 

 Undeflected rays also charged in part: W4(434) ; W9(67i, 672,). 



6. magnetic deflection. 



Difficulty in Observing Effect. 



First overcome by W. Wien, in 1898: W2(ii) ; W3(448) ; W4(423). 

 Effect a thousand times smaller than in the case of the cathode rays. 

 Main discharge must be protected from the influence of the strong mag- 

 netic field employed: W2(ii) ; W3(448) ; W4(422) ; 

 GS(70); W5(S23, 244); 06(237); Tm3(563). 

 Negative results reported: 01(698, 46); Ari(32S); Prti ; Vi ; V3(is) ; 



G3(2o8). 

 Suggestions for observing effect: Ws(S23, 245); Tm3(562). 

 Sense of Deflection, such as to prove the positive charge carried by the rays : 

 W2(i2) ; W3(448) ; W5(523. 245) ; Tm3(568). 

 Part of the rays are deflected in the opposite sense, indicating that part 

 of the rays for a portion of their path are negatively 

 charged: W5(262) ; Tm3(568). 

 Character of the Deflection. 



Non-uniform, spot drawn out in streak, part undeflected: W2(i2) ; 

 W3(448) ; W4(43i) ; Raui(422) ; Tm3(564), 568). 

 Diagram of deflection streak in air, also in H2 shown in Tm3. 

 Not due to impurity in the gas filling: W4(43i). 

 Deflected fluorescence brighter than undeflected, in H2 : W4(432) ; 

 W6(s89). 

 May dift'er in color from undeflected: W4(432) ; W9(675) ; 

 Sm4(iii) ; 84(649). Most deflected fluorescence is 

 always green, but becomes very faint if gas is carefully 

 purified of Hj : Wio(2i3). 

 Deflected beam much less bright than undeflected: W4(432, 435). 



