PHYSICS, PROGRESS OP. 



PHYSIOLOGY, 



are not due to fatigue caused by reversals, and 

 tht neither magnetic nor electric action are 

 LJOIMTT r^^' 1 '"" I)mt ''>' result 

 from loaroontiotMd beating at a low tempera- 



lur*, Mag float 



. .- - hen the riss ex- 



CtJt a fr degrees. S-hini.lt < \\.edemanns 

 - Annal-n." Mvi finds that steel follows weak 

 'Mm* more quickly than in-n. 

 than(r06C. '-. >. Haiti the sus- 



ceptibility of soft steel is to that of iron in the 

 raUoof 4'toS. For fields of on.- unit the sus- 

 ttntibilities are nearly equal, l.ut 

 Kthat of iron is the gr u 



uiiiml magnetite varies with the inclina- 

 of the magnetizing field to the crystallo- 

 graphic axesTlf the results are expressed by 

 drawing* from a given point radii vectors of 

 irh a length that each represents the magneti- 

 sation of the specimen in its own direction when 

 Unrated, the surface in which all th.- ends lie 

 is a cube with rounded edges and slightly hollow 

 These facts seem to show that the theories 



that regard magnetization as the result of the 

 oriental ion of particles of fixed magnet ion 

 are insufficient to explain the magnetization of 

 crystals. 



Elongation.- Moore (" Physical 

 November to December) finds that th.- maxi- 

 mum elongation produced in iron wire by mag- 

 netiiation occurs at an intensity of about 

 Beyond this point the donation diminished. 



Induction. Lecher(\Viedemann's" Annalcn," 

 February), in a paper on unipolar induct ion. di-- 

 OQSSBS the question whether, when a cylindrical 

 magnet turns around lines of force 



are Stationa .day tht.uirht. or turn with 



it, as maintained by Tolver Preston and others. 

 Previous experiments, according to the author, 

 may be interpreted either war. but some recently 

 performed by himself show that th.- frui.-r view 

 b the correct one. Hoptdnson (Royal Inani- 

 tion lecture) suggests that, since in an elect p,- 

 as large as the earth the reversal of the 

 in its coils would muse disturbances 

 would require thousands of millions of 

 yean to reach their maximum value at the cen- 

 i conceivable that the earth's magnetism 

 may be due to currents in iU material SUM 



_.-.. ::.. but il wly dying away. 



Sltdro.maffnehr /W/im/ /W,'. - Weber 

 (Wiedemann's -Annalen." January i find 

 an iron wire whose length is very great rela- 

 tively to tu thickness experiences a pulling 

 force proportional (1) to the intensity of th. 

 ftrti, (?) to its magnetization, and (8) to its sec- 

 tion, when iU end is in a magnet i !i. id and its 

 axis b parallel to the force fines. Wh. n hi.,- 

 awm the force lines it experiences a 

 Mr bvtless in a ratio that is about iw i,, ,,). 

 'firVU. bat quickly approaches unity as the 

 f r 1|r * in strength. 



B ;. \vi-de. 



siann - AnnaJen," March) find- that l.v mac- 

 ******** tfct eonstants of elasticity of so'ft iron 



I by an amount not exceeding ( 

 Ml. r>nr MH! torsion diminish, and the 



contraction to longitnlinal ex- 



^ lrr ? ^f 01116 * nore incom- 

 pwiWi in the magnetic field. 



Mirrors of Magnetism. Thou 

 Walker ( u Ph&osophtaa] Mapa/in.-." !'. 



fin.N that a |.l:r i nmijnrti. 



analogous tu the optical imap- ju-i-din-. 

 mirror, and p-., metrically identical with 



inge (" Itiilli-iin of th. 

 gian Royal Acaxlemy, No. 1) states that n 

 tic.- the oriental 



alone on the direction of the lines of ! 

 tin- field. a it should by theory, but als.. 

 the strength of its ma^n'eti/at i.'.n. ll>- 

 that this ] due io some unknown cause, p^^H 

 to a "circulation of 



M inn-Main . r /'1,1/si,-.- 



sfrumenf*. *]u\iu* ( \Vi<'deinann's "Am, 

 uses for this pur|Mse a small circula; 

 pended by :'. vertical wires. The ccnl 



l.rouu'ht into the plane of the lal 

 movable weight attached to a n>d j,r. 

 downward. Any lateral displacement . 

 upper ends of t'he wires will start waves 

 them, which will perceptibly alTect th< 

 only when the period of the dist urban* -. 

 cides with that of the oscillation of th, 

 about the point of suspension, ui id eventh 

 axis remains vertical. 



I'lHMOLOGY. Intheconclu.ln 

 lecture on th.- work of Carl Ludwi-:. h 

 Sanderson has given a brief summary of the 

 doctrine of vitalism as it now present^ it 

 the form of " neovitalism." Tin- author 

 ed out that the principle which Ludwig and his 

 contemporaries advanced in the middle 

 century a.s fundamental in physiology th 

 explanation of any observed 'process or 

 was to be accepted except in^r that whi. 

 si-ted in referring it to chemical or pi 

 laws was now generally admitted, hi; 1 

 then a new one. lie fore that the current 

 ini:. with exceptions, was in the <>pi 

 tion. It was not denied that, in p-'n.-ral. 

 went on in the Ix.dy as they did out of j| 

 whenever a phenomenon could not be exp 

 on this principle it was regard' 

 at once to have recourse to the hyp<.the-is ,,f a 

 vital force as a way out of the diilicu'r 

 movement had recently sprung up i 

 under the name of neovitalism which .. 

 si-ht .reined to return to the old position. 

 eral writers had shown a tendency to fol 

 ami it was the subject of one of the ad. In 

 the Liil>eck meeting of the (J.-rman Asso, 

 of Naturalists and I'hy-icians. < >n com; 

 the position of the oeovitalistfl with the ii. 

 current fifty years n_ 



considerable difTereii. :h.m. '["<,, 



in truth, no revival of the hypothc-. 



for it is rcco^ni/.ed tluit if the wor: 

 is u-ed to mean something that manifest^ 

 by meanurable elTe< ; no ind; 



that ich as ti 



recogni/'-s, jx in operation in the ori' 

 the poMtion now tal-n it is pointed out t 1 

 certain recent instances processes of lif 

 were at first regarded as entirely ; 

 (di.-mjcal d :"orm o precisely' n 



were expected to do to phy-i< al and ch 



of these which is especially 

 of attention i< that of the lymphatic y-i.-m. It 

 hal appeared from the investigations o| Ludwig 

 and his pupils that the efficient cause of the 



