( ftoi') ) 



and a small tVaclioii ctl' llic least xolalilc is proseiil in llic distillale. 

 Tlial the two (|iiaiiliti«'s will llicii «lillrr little in w ciulil and tlierefore 

 the deviation IV(un tli(> law is <'(»in|»;irali\('lv small, is not siranü'e in 

 my opinion. 



I think to liax'e shown in this way, that YoiNCi's rnle is a proof 

 of the excellent way in which YoincTs still heads work, hnl that 

 fi'oni a point of \iew of qnanfitalive analysis wo mnst only lake 

 this rnle as an ap|)lication of the most obvious operalion, vi/. that of 

 sepa,ratiiig a substance iu pure state from a mixture and then weighing 

 it separately. 



Fh.ysictd Lab. of tin' Unkwrsiti/. Amstenhiin. 



Physics. — "E/('ct.roi)Hi(/netic plienompna in a si/sfrm movlmi ict'f/t 

 (lilt/ vehcitji swrdh'r than that of Ii(//it.'' By Prof. H. A. LorExNTZ. 



§ 1. The problem of determining the inllueuce exerted on electric 

 and optical phenomena by a translation, sncli as all systems have in 

 virtue of the Earth's annual luotion, admits of a comparatively 

 simple solution, so long as oidy those terms need be taken into 

 account, which are propoi'tional to the tirst |)Ower of the ratio 

 between the \elocity (^f ti'anslation /r and the velocity of light c. 



Cases in which (uiantities of the second oi-der, i.e. of the order — , 



c" 



may be pei'ceptible, |)resent moi-e difHicnlties. The tii-st example of 



this kind is Miciiki.son's w(dl kno\\ n intei-ference-ex|)eriment, the 



uegaliv-e resnll of which has led Kitz (4krat,I) and myself to the 



conclusion that the dimensions of solid bodies are slightly altered 



by their motion throuuii the a(Mher. 



Some now experinK^ils in w liicli a second order ellecl \\as sought 

 foi- have recently been pnblished. IJ\vi,ki(;m') and Hijack ") have 

 examined iIk^ (piestion whether the l']ai*th's motion may cause a 

 l)0(ly to become (loni)ly retVaciing: at lirst sight this might be 

 ex|>ecte(l, if tlu^ Jnst nientione»! ehange of dimcMisions is admitted. 

 Both pliNsieists li;i\-e howex'er come to a ne,!j,"at i\(^ resnll. 



In the second jilace Tijoiton and Noin.K '.') have endeavoni'e<l to 

 detect a turninu conple actinu on a eharu'ed cond(Mis(M". whose |>lates 

 make a <'CM'tain aniile with lli<' dii'oclion of translation. The theory 



■) Rayleigh, I'liil. Mag. (Ci 1 (I'Mm, p. 07s. 



■^) Brack, Phil. Mag. (0) 7 (r.K)4), p. 'Ml. 



'■■) Troutun and Xohle, London Roy. See Trans. A -202 (19Ü"3), p. 165. 



