, 1885.] 



KNOWLEDGE ♦ 



support, S, is made by fitting ; 

 well dried, into a wooden base, t 

 with a cork or wooden plug, wt 



pit 



ii needle driven into tlie 

 porting the paper or -vvi 

 end of tlie cylinder is 

 that depicted in Fig. 47), 



.l.r, CD. Near eac 



iliiirt (a miniature 



ladc from a piece of bra 



re, and carrying a small pith ball, suspended by a ]i 

 of cotton thread. To ensure insulation it is advisable to 

 close the bottom of the glass support by a plug fitted 

 with scaling-wiix, &r. The outer sui-face of the tube 



should ali 

 of shellac van) i.l, (Kx. 1. 

 On the apprniirh ><f t\i 

 C D becomes electrified 

 becoming negative (oi 



,-ith a thin, ( 



I laye 



"isitively electrified rood A B, 

 ,' induction, the near end C 

 1 A) and 



the remote end D becoming positive (similar to A). The 

 pith balls take iip the positions shown because they are 

 charged similarly to the respectively adjacent ends of 

 the cylinder and wire supports. Repulsion ensues from 

 this. The ball at C also shares the attraction of A. On 

 removing A B, C D relapses into its normal iinelectrified 

 state, and the balls again fall into the vertical position. 

 This demonstrates that AB imparted none of its charge 

 to CD. 



Fig. 53. 



Ex. XCVIII. — We can show induction in another way. 

 Hold an electrified rod, 11 (Fig. 53) over the end L' of a 

 wooden lath LL' (Ex. LXXIII.), supported on an in- 

 verted tumbler, G, resting on any convenient support. 

 The tumbler should be previously thoroughly warmed 

 and dried for insulatory purposes. A is another support, 

 uninsulated, and carrj-ing a small quantity of bran, 

 paper-clippings, gold-leaf fragments, &c. These sub- 

 stances are placed under the remote end L of the lath. 





I the 



appr 



u-li of K, , 



lath. If R 



pieces of paper, Ar 



exerted by thi.s .li n 



in consequencr if i 



faces ; they cim i 



becoming also iiu.--ii 



l-epelled ; they in 



negative charge oi 



become neutralised, when they 



inductively electrified and att 



the paper particles are kej 



between A and L until (Imt i i 



?'.('., contains no more positiv 



th( 



;,lsM 



A, . 



,epul« 



vithdra 

 ditlu.ses 



■LiMt ively-charged sur- 



I.. and consequentl}-, 



I ; t hey are therefore 



induce an additional 



contact with A, and 



re ready to be again 



•ted by L. In this way, 



iiK.viiig iTp and down 



nf ilirlath is discharged, 



l.riiicity. When this 



If then R is 



en, the negative charge concentrated at 

 itself over the lath, and attraction, although 



feebler than before, is again exerted by L upon i 



xperiment 



Ex. XCIX.— In Fig. 54 is shown a 

 of a somewhat similar character. E is an egg (ai _ 

 a pared carrot, parsnip, turnip, potato, &c., will answer 

 equally well) ; this is placed on a dry, warm wine-glass 

 or other insulating support. The electrified rod, G, is 

 brought near the end a of the egg. Induction ensues, 

 and the two ends of the egg become oppositely electrified. 

 If the finger be placed at the end 6, it will practically 

 remove that end of the egg to an infinite distance, when 

 only one kind of electricity will remain, namely, that 

 located at a. If, now, the finger is removed, and then 

 G, E will be found to be electrified and capable of 

 attracting light bodies, such as the suspended pith ball, 

 &c. Of course, neither the finger nor any other con- 

 ductor should be allowed to touch the egg, or it will be 

 discharged. 



HYSTERIA AS RELIGION. 



AN Indiana journal has a long account of the strange 

 doings of a so-called female evangelist who is going 

 through the country holding revival meetings in which 

 alleged " trances " figure conspicuously. It is complained 

 by sober-minded and observing professors of religion that 

 the effecits of these revivals are evanescent, and that i 

 fact the excitement passes as rapidly as it 

 ministry have been accused of jealousy of t 

 and the leaders of them, but the general disapproval 

 entertained toward such methods by thinking pastors 

 rests upon far higher grounds. 



Medical science does not hesitate to assign the methods 

 here used for religious purposes to the category of 

 diseases. The kind of trances into which the Indiana 

 cvaiii,'! Ii-i fill- 1- i:i ! mysterious to the student of medi- 

 i.ii,,, II, I,, It" as one of the manifestations of 



il,,. ,M I ~c called hysteria. And in the 



he emotional outbursts at such 

 influence of similar abnormal 



The 



revival meetiug; _ 

 conditions is perceived. 



To the physician's apprehension there is in these 

 violent physical phenomena no question of mental con- 

 viction or conversion, no evidence of any intellectual 

 jirocess whatever ; but solely and simply an involuntary 

 and irrational nervous convulsion, propagated by con- 

 taiMoii, trulv epidemic in its character, and inviting treat- 

 mriit Iv inrilicine like any other iihyslcnl cuuplaint. 

 Tlir eiii.lnnir character of such (lutbroaks has indeed 

 Wvn .-niu-lnsively established. The l rerise asjectsof 

 the epidc'iuic nuiv be determined bv almost any trivial 

 external incident," and it depends upon .something of this 



