,,response ,,9 ,,! ,,liv+ ,,& ,,non-,,liv+ ,,by ,,jagadis ,,*und] ,,bose1 ,m4,a47,,cantab471 ,d4,sc47,,lond47 ,,pr(essor1 ,,presid5cy ,,college1 ,,calcutta ,,) ,,illu/rations ,,longmans1 ,,gre51 ,,& ,,co4 #ci ,,pat]no/] ,,r[1 ,,london ,,new ,,york ,,& ,,bombay #aijb ,all rights res]v$ ',! real is "o3 wise m5 call x v>i\sly' ,,rig ,,v$a ,to my ,c\ntrym5 ,?is ,"w is ,d$icat$ ,,preface ,i h 9 ! pres5t "w put 9 a connect$ & a m complete =m results1 "s ( :i* h be5 publi%$ 9 ! foll[+ ,pap]s3 ',de la ,gnralit des ,phnomnes ,molculaires produits p> l',electricit sur la matire ,inorganique et sur la matire ,vivante4' 7,travaux du ,congrs ,int]national de ,physique4 ,p>is1 #aijj47 ',on ! ,simil>ity ( ,effect ( ,electrical ,/imulus on ,inorganic & ,liv+ ,sub/ances4' 7,report1 ,brad=d ,meet+ ,briti% ,association1 #aijj4--;,electrician47 ',response ( ,inorganic ,matt] to ,/imulus4' 7,friday ,ev5+ ,disc\rse1 ,royal ,in/itution1 ,may#aija47 ',on ,electric ,response ( ,inorganic ,sub/ances4 ,prelim9>y ,notice4' 7,royal ,society1 ,june#aija47 ',on ,electric ,response ( ,ord9>y ,plants "u ,me*anical ,/imulus4' 7,j\rnal ,l9nean ,society1 #aijb47 ',sur la ,rponse ,electrique dans les ,mtaux1 les ,tissus ,animaux et ,vgtaux4' 7,socit de ,physique1 ,p>is1 #aijb47 ',on ! ,electro-,motive ,wave accompany+ ,me*anical ,di/urbance 9 ,metals 9 contact ) ,electrolyte4' 7,proce$+s ,royal ,society1 vol4#gj47 ',on ! ,/ra9 ,!ory ( ,vision & ( ,photographic ,action4' 7,j\rnal ,royal ,photographic ,society1 vol4xxvi47 ,^! inve/igations 7 comm5c$ 9 ,india1 & ,i take ?is opportunity to express my grateful ackn[l$gm5ts to ! ,manag]s ( ! ,royal ,in/itution1 = ! facilities (f]$ me to complete !m at ! ,davy-,f>aday ,laboratory4 ,j4,c4 ,,bose4 ,,davy-,,f>aday ,,laboratory1 ,,royal ,,in/itution1 ,,london3 ,may#aijb4 ,,cont5ts ,,*apt] ,i ,,! ,,me*anical ,,response ,,( ,,liv+ ,,sub/ances ,,page ,me*anical response--,diff]5t k9ds ( /imuli--,myograph --,*>act]i/ics ( response-curve3 p]iod1 amplitude1 =m--,modification ( response-curves #a ,,*apt] ,,ii ,,electric ,,response ,conditions = obta9+ electric response--,me?od ( injury--,curr5t ( injury--,injur$ end1 cuproid3 un9jur$1 z9coid--,curr5t ( response 9 n]ve f m excit$ to less excit$--,difficulties ( pres5t nom5clature--,electric record]--,two types ( response1 positive & negative--,univ]sal applicability ( electric mode ( response--,electric response a measure ( physiological activity--,electric response 9 plants #e ,,*apt] ,,iii ,,electric ,,response ,,9 ,,plants--,,me?od ,,( ,,negative ,,v>iation ,negative v>iation--,response record]--,photographic record]--,comp5sator--,means ( graduat+ int5sity ( /imulus--,spr+-tapp] & torsional vibrator--,int5sity ( /imulus dep5d5t on amplitude ( vibration--,effectiv5ess ( /imulus dep5d5t on rapidity also #ag ,,*apt] ,,iv ,,electric ,,response ,,9 ,,plants--,,block ,,me?od ,me?od ( block--,advantages ( block me?od--,plant response a physiological ph5om5on--,abolition ( response by an/hetics & poisons--,abolition ( response :5 plant is kill$ by hot wat] #bg ,,*apt] ,v ,,plant ,,response--,,on ,,! ,,effects ,,( ,,s+le ,,/imulus ,,& ,,( ,,sup]pos$ ,,/imuli ,effect ( s+le /imulus--,sup]position ( /imuli--,additive effect--,/aircase effect--,fatigue--,no fatigue :5 suffici5t int]val betwe5 /imuli--,app>5t fatigue :5 /imulation frequ5cy is increas$--,fatigue "u cont9u\s /imulation #ce ,,*apt] ,,vi ,,plant ,,response--,,on ,,diphasic ,,v>iation ,diphasic v>iation--,positive aft]-effect & positive response--,radial ,e4,m4 v>iation #dd ,,*apt] ,,vii ,,plant ,,response--,,on ,,! ,,relation ,,betwe5 ,,/imulus ,,& ,,response ,increas$ response ) increas+ /imulus--,app>5t dim9ution ( response ) excessively /rong /imulus #ea ,,*apt] ,,viii ,,plant ,,response--,,on ,,! ,,influ5ce ,,( ,,temp]ature ,effect ( v l[ temp]ature--,influ5ce ( high temp]ature--,det]m9ation ( dea?-po9t--,increas$ response z aft]-effect ( temp]ature v>iation--,dea? ( plant & abolition ( response by ! action ( /eam #ei ,,*apt] ,,ix ,,plant ,,response--,,effect ,,( ,,an,,/hetics ,,& ,,poisons ,effect ( an/hetics1 a te/ ( vital "* ( response--,effect ( *lor(orm--,effect ( *loral--,effect ( =mal9--,me?od 9 :i* response is unaffect$ by v>iation ( resi/ance--,advantage ( block me?od--,effect ( dose #ga ,,*apt] ,x ,,response ,,9 ,,metals ,is response f\nd 9 inorganic sub/ances8--,exp]im5t on t91 block me?od--,anomalies ( exi/+ t]m9ology--,response by me?od ( depression--,response by me?od ( exaltation #ha ,,*apt] ,,xi ,,inorganic ,,response--,,modifi$ ,,app>atus ,,to ,,exhibit ,,response ,,9 ,,metals ,conditions ( obta9+ quantitative measurem5ts--,modification ( ! block me?od--,vibration cell--,application ( /imulus--,graduation ( ! int5sity ( /imulus--,consid]ations %[+ t electric response is due to molecul> di/urbance--,te/ exp]im5t--,molecul> voltaic cell #ia ,,*apt] ,,xii ,,inorganic ,,response--,,me?od ,,( ,,ensur+ ,,consi/5t ,,results ,prep>ation ( wire--,effect ( s+le /imulus #ajj ,,*apt] ,,xiii ,,inorganic ,,response--,,molecul> ,,mobility3 ,,its ,,influ5ce ,,on ,,response ,effects ( molecul> in]tia--,prolongation ( p]iod ( recov]y by ov]/ra9--,molecul> model--,r$uction ( molecul> sluggi%ness att5d$ by quick5$ recov]y & height5$ response--,effect ( temp]ature--,modification ( lat5t p]iod & p]iod ( recov]y by ! action ( *emical reag5ts--,diphasic v>iation #ajd ,,*apt] ,,xiv ,,inorganic ,,response--,,fatigue1 ,,/aircase1 ,,& ,,modifi$ ,,response ,fatigue 9 metals--,fatigue "u cont9u\s /imulation--,/aircase effect--,rev]s$ responses due to molecul> modification 9 n]ve & 9 metal1 & _! trans=mation into normal aft] cont9u\s /imulation--,increas$ response aft] cont9u\s /imulation #aah ,,*apt] ,,xv ,,inorganic ,,response--,,relation ,,betwe5 ,,/imulus ,,& ,,response--,,sup]position ,,( ,,/imuli ,relation betwe5 /imulus & response--,magnetic analogue--,increase ( response ) increas+ /imulus--,?re%old ( response--,sup]position ( /imuli--,hy/]esis #aca ,,*apt] ,,xvi ,,inorganic ,,response--,,effect ,,( ,,*emical ,,reag5ts ,action ( *emical reag5ts--,action ( /imulants on metals--,action ( depressants on metals--,effect ( 'poisons' on metals--,opposite effect ( l>ge & small doses #aci ,,*apt] ,,xvii ,,on ,,! ,,/imulus ,,( ,,light ,,& ,,ret9al ,,curr5ts ,visual impulse3 7#a7 *emical !ory2 7#b7 electrical !ory--,ret9al curr5ts--,normal response positive--,inorganic response "u /imulus ( light--,typical exp]im5t on ! electrical effect induc$ by light #adh ,,*apt] ,,xviii ,,inorganic ,,response--,,influ5ce ,,( ,,v>i\s ,,conditions ,,on ,,! ,,response ,,to ,,/imulus ,,( ,,light ,effect ( temp]ature--,effect ( increas+ l5g? ( exposure--,relation betwe5 int5sity ( light & magnitude ( response--,aft]-oscillation--,abnormal effects3 7#a7 prelim9>y negative twit*2 7#b7 rev]sal ( response2 7#c7 transi5t positive twit* on cessation ( light2 7#d7 decl9e & rev]sal--,rsum #aeh ,,*apt] ,,xix ,,visual ,,analogues ,effect ( light ( %ort duration--,aft]-oscillation--,positive & negative aft]-images--,b9ocul> alt]nation ( vision--,p]iod ( alt]nation modifi$ by physical condition--,aft]-images & _! revival--,unconsci\s visual impression4 #agj ,,*apt] ,,xx ,,g5]al ,,survey ,,& ,,conclusion #aha ,,index #aic ,,illu/rations ,,fig4 ,,page #a4 ,,me*anical ,,lev] ,,record] #c #b4 ,,electric ,,me?od ,,( ,,detect+ ,,n]ve ,,response #f #c4 ,,diagram ,,%[+ ,,injur$ ,,end ,,( ,,n]ve ,,corresponds ,,to #h ,,copp] ,,9 ,a ,,voltaic ,,elem5t #d4 ,,electric ,,record] #aa #e4 ,,simultane\s ,,record ,,( ,,me*anical ,,& ,,electrical #ac ,,responses #f4 ,,negative ,,v>iation ,,9 ,,plants #ai #g4 ,,photographic ,,record ,,( ,,negative ,,v>iation ,,9 ,,plants #bj #h4 ,,response ,,record] #ba #i4 ,,! ,,comp5sator #bb #aj4 ,,! ,,spr+-,,tapp] #bc #aa4 ,,! ,,torsional ,,vibrator #bd #ab4 ,,response ,,9 ,,plant ,,to ,,me*anical ,,tap ,,or ,,vibration #be #ac4 ,,influ5ce ,,( ,,sudd5ness ,,on ,,! ,,effici5cy ,,( #bf ,,/imulus #ad4 ,,! ,,me?od ,,( ,,block #bh #ae4 ,,response ,,9 ,,plant ,,completely ,,imm]s$ ,,"u ,,wat] #bi #af4 ,,uni=m ,,responses ,,9 ,,plant #cf #ag4 ,,fusion ,,( ,,effect ,,"u ,,rapidly ,,succe$+ ,,/imuli ,,9 #cf ,,muscle ,,& ,,9 ,,plant #ah4 ,,additive ,,effect ,,( ,,s+ly ,,ineffective ,,/imuli ,,on #cg ,,plant #ai4 ',,/aircase ,,effect' ,,9 ,,plant #cg #bj4 ,,appe>ance ,,( ,,fatigue ,,9 ,,plant ,,"u ,,%ort5$ #ci ,,p]iod ,,( ,,re/ #ba4 ,,fatigue ,,9 ,,cel]y #dj #bb4 ,,fatigue ,,9 ,,caulifl[]-,,/alk #da #bc4 ,,fatigue ,,f ,,previ\s ,,ov]/ra9 #da #bd4 ,,fatigue ,,"u ,,cont9u\s ,,/imulation ,,9 ,,cel]y #db #be4 ,,effect ,,( ,,re/ ,,9 ,,removal ,,( ,,fatigue ,,9 ,,plant #dc #bf4 ,,diphasic ,,v>iation ,,9 ,,plant #df #bg1 #bh4 ,,abnormal ,,positive ,,responses ,,9 ,,/ale ,,plant #dh1 #di ,,trans=m$ ,,into ,,normal ,,negative ,,"u ,,/rong ,,/imulation #bi4 ,,radial ,e4,m4 ,,v>iation #ej #cj4 ,,curves ,,%[+ ,,! ,,relation ,,betwe5 ,,int5sity ,,( #eb ,,/imulus ,,& ,,response ,,9 ,,muscle ,,& ,,n]ve #ca4 ,,increas+ ,,responses ,,to ,,increas+ ,,/imuli 7,,taps7 ,,9 #eb ,,plants #cb4 ,,increas+ ,,responses ,,to ,,increas+ ,,vibrational #ec ,,/imuli ,,9 ,,plants #cc4 ,,responses ,,to ,,increas+ ,,/imuli ,,9 ,,fre% ,,& ,,/ale #ed ,,specim5s ,,( ,,plants #cd4 ,,app>5t ,,dim9ution ,,( ,,response ,,caus$ ,,by ,,fatigue #eg ,,"u ,,/rong ,,/imulation #ce4 ,,dim9ution ,,( ,,response ,,9 ,,eu*>is ,,lily ,,at ,,l[ #fa ,,temp]ature #cf4 ,,records ,,%[+ ,,! ,,diff]5ce ,,9 ,,! ,,effects ,,( ,,l[ #fb ,,temp]ature ,,on ,,ivy1 ,,holly1 ,,& ,,eu*>is ,,lily #cg4 ,,plant ,,*amb] ,,= ,,/udy+ ,,! ,,effect ,,( ,,temp]ature #fd ,,& ,,an,,/hetics #ch4 ,,effect ,,( ,,high ,,temp]ature ,,on ,,plant ,,response #fd #ci4 ,,aft]-,,effect ,,on ,,! ,,response ,,due ,,to ,,temp]ature #ff ,,v>iation #dj4 ,,records ,,( ,,responses ,,9 ,,eu*>is ,,lily ,,dur+ ,,rise #fg ,,& ,,fall ,,( ,,temp]ature #da4 ,,curve ,,%[+ ,,v>iation ,,( ,,s5sitiv5ess ,,dur+ ,a #fh ,,cycle ,,( ,,temp]ature ,,v>iation #db4 ,,record ,,( ,,effect ,,( ,,/eam ,,9 ,,abolition ,,( ,,response #fi ,,at ,,dea? ,,( ,,plant #dc4 ,,effect ,,( ,,*lor(orm ,,on ,,n]ve ,,response #gb #dd4 ,,effect ,,( ,,*lor(orm ,,on ,,! ,,responses ,,( ,,c>rot #gd #de4 ,,action ,,( ,,*loral ,,hydrate ,,on ,,plant ,,responses #ge #df4 ,,action ,,( ,,=mal9 ,,on ,,radi% #ge #dg4 ,,action ,,( ,,sodium ,,hydrate ,,9 ,,aboli%+ ,,! ,,response #gh ,,9 ,,plant #dh4 ,,/imulat+ ,,action ,,( ,,poison ,,9 ,,small ,,doses ,,9 #gi ,,plants #di4 ,,! ,,poison\s ,,effect ,,( ,,/rong] ,,dose ,,( ,,koh #gi #ej4 ,,block ,,me?od ,,= ,,obta9+ ,,response ,,9 ,,t9 #hc #ea4 ,,response ,,to ,,me*anical ,,/imulation ,,9 ,a ,zn-,cu ,,c\ple #he #eb4 ,,electric ,,response ,,9 ,,metal ,,by ,,! ,,me?od ,,( ,,relative #hh ,,depression 7,,negative ,,v>iation7 #ec4 ,,me?od ,,( ,,relative ,,exaltation #hi #ed4 ,,v>i\s ,,cases ,,( ,,positive ,,& ,,negative ,,v>iation #ij #ee4 ,,modifications ,,( ,,! ,,block ,,me?od ,,= ,,exhibit+ #ic ,,electric ,,response ,,9 ,,metals #ef4 ,,equal ,,& ,,opposite ,,responses ,,giv5 ,,by ,,two ,,ends ,,( #ie ,,! ,,wire #eg4 ,,top ,,view ,,( ,,! ,,vibration ,,cell #if #eh4 ,,influ5ce ,,( ,,anneal+ ,,9 ,,! ,,enhancem5t ,,( #aja ,,response ,,9 ,,metals #ei4 ,,uni=m ,,electric ,,responses ,,9 ,,metals #ajb #fj4 ,,p]si/5ce ,,( ,,aft]-,,effect #aje #fa4 ,,prolongation ,,( ,,p]iod ,,( ,,recov]y ,,aft] ,,ov]/ra9 #ajf #fb4 ,,molecul> ,,model #ajg #fc1 #fd4 ,,effects ,,( ,,removal ,,( ,,molecul> ,,sluggi%ness ,,9 #aji1 #aaj ,,quick5$ ,,recov]y ,,& ,,height5$ ,,response ,,9 ,,metals #fe4 ,,effect ,,( ,,temp]ature ,,on ,,response ,,9 ,,metals #aaa #ff4 ,,diphasic ,,v>iation ,,9 ,,metals #aac #fg4 ,,negative1 ,,diphasic1 ,,& ,,positive ,,resultant ,,response #aae ,,9 ,,metals #fh4 ,,cont9u\s ,,trans=mation ,,f ,,negative ,,to ,,positive #aaf ,,?r\gh ,,int]m$iate ,,diphasic ,,response #fi4 ,,fatigue ,,9 ,,muscle #aah #gj4 ,,fatigue ,,9 ,,plat9um #aah #ga4 ,,fatigue ,,9 ,,t9 #aai #gb4 ,,appe>ance ,,( ,,fatigue ,,due ,,to ,,%ort5+ ,,! ,,p]iod #abj ,,( ,,recov]y #gc4 ,,fatigue ,,9 ,,metal ,,"u ,,cont9u\s ,,/imulation #aba #gd4 ',,/aircase' ,,response ,,9 ,,muscle ,,& ,,9 ,,metal #abb #ge4 ,,abnormal ,,response ,,9 ,,n]ve ,,conv]t$ ,,into ,,normal #abd ,,"u ,,cont9u$ ,,/imulation #gf1 #gg4 ,,abnormal ,,response ,,9 ,,t9 ,,& ,,plat9um ,,conv]t$ ,,into #abe ,,normal ,,"u ,,cont9u$ ,,/imulation #gh4 ,,gradual ,,transition ,,f ,,abnormal ,,to ,,normal ,,response #abf ,,9 ,,plat9um #gi4 ,,increase ,,( ,,response ,,9 ,,n]ve ,,aft] ,,cont9u\s #abg ,,/imulation #hj1 #ha4 ,,response ,,9 ,,t9 ,,& ,,plat9um ,,enhanc$ ,,aft] #abg1 #abh ,,cont9u\s ,,/imulation #hb4 ,,magnetic ,,analogue #acb #hc1 #hd4 ,,records ,,( ,,responses ,,to ,,increas+ ,,/imuli ,,9 ,,t9 #acd1 #ace #he4 ,,ineffective ,,/imulus ,,becom+ ,,effective ,,by #ace ,,sup]position #hf4 ,,incomplete ,,& ,,complete ,,fusion ,,( ,,effects #acf #hg4 ,,cyclic ,,curve ,,= ,,maximum ,,effects ,,%[+ ,,hy/]esis #acg #hh4 ,,action ,,( ,,poison ,,9 ,,aboli%+ ,,response ,,9 ,,n]ve #aci #hi4 ,,action ,,( ,,/imulant ,,on ,,t9 #ada #ij4 ,,action ,,( ,,/imulant ,,on ,,plat9um #adb #ia4 ,,depress+ ,,effect ,,( ,k,br ,,on ,,t9 #adc #ib4 ,,abolition ,,( ,,response ,,9 ,,metals ,,by ',,poison' #adc #ic4 ',,molecul> ,,arre/' ,,by ,,! ,,action ,,( ',,poison' #ade #id4 ,,opposite ,,effects ,,( ,,small ,,& ,,l>ge ,,doses ,,on ,,! #adf ,,response ,,9 ,,metals #ie4 ,,ret9al ,,response ,,to ,,light #aej #if4 ,,response ,,( ,,s5sitive ,,cell ,,to ,,light #aeb #ig4 ,,typical ,,exp]im5t ,,on ,,! ,e4,m4 ,,v>iation ,,produc$ ,,by #aed ,,light #ih4 ,,modification ,,( ,,! ,,photo-,,s5sitive ,,cell #aee #ii4 ,,responses ,,9 ,,frog',s ,,ret9a #aef #ajj4 ,,responses ,,9 ,,s5sitive ,,photo-,,cell #aeg #aja4 ,,effect ,,( ,,temp]ature ,,on ,,! ,,response ,,to ,,light #aei ,,/imulus #ajb4 ,,effect ,,( ,,duration ,,( ,,exposure ,,on ,,! ,,response #aei #ajc4 ,,responses ,,( ,,s5sitive ,,cell ,,to ,,increas+ #afa ,,int5sities ,,( ,,light #ajd4 ,,relation ,,betwe5 ,,! ,,int5sity ,,( ,,light ,,& #afb ,,magnitude ,,( ,,response #aje4 ,,aft]-,,oscillation #afc #ajf4 ,,transi5t ,,positive ,,increase ,,( ,,response ,,9 ,,! #afd ,,frog',s ,,ret9a ,,on ,,! ,,cessation ,,( ,,light #ajg4 ,,transi5t ,,positive ,,increase ,,( ,,response ,,9 ,,! #afe ,,s5sitive ,,cell #ajh4 ,,decl9e ,,"u ,,! ,,cont9u\s ,,action ,,( ,,light #aff #aji4 ,,c]ta9 ,,aft]-,,effects ,,( ,,light #afh #aaj4 ,,aft]-,,effect ,,( ,,light ,,( ,,%ort ,,duration #agb #aaa4 ,,/]eoscopic ,,design ,,= ,,! ,,exhibition ,,( ,,b9ocul> #agf ,,alt]nation ,,( ,,vision #aab4 ,,uni=m ,,responses ,,9 ,,n]ve1 ,,plant1 ,,& ,,metal #ahd #aac4 ,,fatigue ,,9 ,,muscle1 ,,plant1 ,,& ,,metal #ahe #aad4 ',,/aircase' ,,effect ,,9 ,,muscle1 ,,plant1 ,,& ,,metal #ahf #aae4 ,,increase ,,( ,,response ,,aft] ,,cont9u\s ,,/imulation ,,9 #ahf ,,n]ve ,,& ,,metal #aaf4 ,,modifi$ ,,abnormal ,,response ,,9 ,,n]ve ,,& ,,metal #ahg ,,trans=m$ ,,into ,,normal ,,response ,,aft] ,,cont9u\s ,,/imulation #aag4 ,,action ,,( ,,! ,,same ',,poison' ,,9 ,,! ,,abolition ,,( #ahi ,,response ,,9 ,,n]ve1 ,,plant1 ,,& ,,metal ,,response ,,9 ,,! ,,liv+ ,,& ,,non-,,liv+ ,,*apt] ,i ,,! ,,me*anical ,,response ,,( ,,liv+ ,,sub/ances ,me*anical response--,diff]5t k9ds ( /imuli--,myograph--,*>act]i/ics ( response-curve3 p]iod1 amplitude1 =m--,modification ( response-curves4 ,"o ( ! mo/ /rik+ effects ( ext]nal di/urbance on c]ta9 types ( liv+ sub/ance is a visible *ange ( =m4 ,?us1 a piece ( muscle :5 p9*$ contracts4 ,! ext]nal di/urbance :i* produc$ ?is *ange is call$ ! /imulus4 ,! body :i* is ?us capable ( respond+ is said to be irritable or excitable4 ,a /imulus ?us produces a /ate ( excitability :i* may sometimes be express$ by *ange ( =m4 ,me*anical response to diff]5t k9ds ( /imuli4--,?is reaction "u /imulus is se5 ev5 9 ! l[e/ organisms2 9 "s ( ! amoeboid rhizopods1 = in/ance4 ,^! lumpy protoplasmic bodies1 usually elongat$ :ile creep+1 if me*anically j>r$1 contract into a sph]ical =m4 ,if1 in/ead ( me*anical di/urbance1 we apply salt solution1 !y aga9 contract1 9 ! same way z be=e4 ,simil> effects are produc$ by sudd5 illum9ation1 or by rise ( temp]ature1 or by electric %ock4 ,a liv+ sub/ance may ?us be put into an excitatory /ate by ei!r me*anical1 *emical1 !rmal1 electrical1 or light /imulus4 ,n only does ! po9t /imulat$ %[ ! effect ( /imulus1 b t effect may sometimes be conduct$ ev5 to a consid]able di/ance4 ,?is p[] ( conduct+ /imulus1 ?\gh common to all liv+ sub/ances1 is pres5t 9 v diff]5t degrees4 ,:ile 9 "s =ms ( animal tissue irritation spreads1 at a v sl[ rate1 only to po9ts 9 close neighb\rhood1 9 o!r =ms1 z = example 9 n]ves1 conduction is v rapid & rea*es f>4 ,! visible mode ( response by *ange ( =m may p]haps be be/ /udi$ 9 a piece ( muscle4 ,:5 ?is is p9*$1 or an electrical %ock is s5t ?r\gh x1 x becomes %ort] & broad]4 ,a responsive twit* is ?us produc$4 ,! excitatory /ate !n disappe>s1 & ! muscle is se5 to relax into its normal =m4 ,me*anical lev] record]4--,9 ! case ( contraction ( muscle1 ! effect is v quick1 ! twit* takes place 9 too %ort a "t = detail$ obs]vation by ord9>y means4 ,a myographic app>atus is !re=e us$1 by means ( :i* ! *anges 9 ! muscle are self-record$4 ,?us we obta9 a hi/ory ( its *ange & recov]y f ! *ange4 ,! muscle is connect$ to "o end ( a writ+ lev]4 ,:5 ! muscle contracts1 ! trac+ po9t is pull$ up 9 "o direction1 say to ! "r4 ,! ext5t ( ?is pull dep5ds on ! am\nt ( contraction4 ,a b& ( pap] or a revolv+ drum-surface moves at a uni=m spe$ at "r angles to ! direction ( motion ( ! writ+ lev]4 ,:5 ! muscle recov]s f ! /imulus1 x relaxes into its orig9al =m1 & ! writ+ po9t traces ! recov]y z x moves n[ to ! left1 rega9+ its fir/ position4 ,a curve is ?us describ$1 ! ris+ portion ( :i* is due to contraction1 & ! fall+ portion to relaxation or recov]y4 ,! ord9ate ( ! curve repres5ts ! int5sity ( response1 & ! abscissa ! "t 7fig4#a74 ,illu/ration3 ,,fig4#a4--,,me*anical ,,lev] ,,record] ,! muscle ,m ) ! atta*$ bone is securely held at "o end1 ! o!r end be+ connect$ ) ! writ+ lev]4 ,"u ! action ( /imulus ! contract+ muscle pulls ! lev] & moves ! trac+ po9t to ! "r ov] ! travell+ record+ surface ,p4 ,:5 ! muscle recov]s f contraction1 ! trac+ po9t returns to its orig9al position4 ,see on ,p ! record ( muscle curve4 ,*>act]i/ics ( ! response-curve3 7#a7 ,p]iod1 7#b7 ,amplitude1 7#c7 ,=m4--,j z a wave ( s\nd is *>act]is$ by its 7#a7 p]iod1 7#b7 amplitude1 & 7#c7 =m1 s may ^! response-curves be di/+ui%$ f ea* o!r4 ,z reg>ds ! p]iod1 !re is an enorm\s v>iation1 correspond+ to ! functional activity ( ! muscle4 ,= in/ance1 9 tortoise x may be z high z a second1 :]eas 9 ! w+-muscles ( _m insects x is z small z #a_/cjj "p ( a second4 ',x is probable t a cont9u\s graduat$ scale might1 z sugge/$ by ,h]mann1 be drawn up 9 ! animal k+dom1 f ! excessively rapid contraction ( insects to ^? ( tortoises & hib]nat+ dormice4'#a ,diff]5ces 9 =m & amplitude ( curve are well illu/rat$ by v>i\s muscles ( ! tortoise4 ,! curve = ! muscle ( ! neck1 us$ = rapid )drawal ( ! head on approa* ( dang]1 is q diff]5t f t ( ! pectoral muscle ( ! same animal1 us$ = its sluggi% movem5ts4 ,aga91 progressive *anges 9 ! same muscle are well se5 9 ! modifications ( =m :i* consecutive muscle-curves gradually und]go4 ,9 a dy+ muscle1 = example1 ! amplitude ( succe$+ curves is cont9u\sly dim9i%$1 & ! curves !mselves are elongat$4 ,num]\s illu/rations w be se5 lat]1 ( ! effect1 9 *ang+ ! =m ( ! curve1 ( ! increas$ excitation or depression produc$ by v>i\s ag5cies4 ,?us ^! response records give u a means ( /udy+ ! effect ( /imulus1 & ! modification ( response1 "u v>y+ ext]nal conditions1 advantage be+ tak5 ( ! me*anical contraction produc$ 9 ! tissue by ! /imulus4 ,b !re are o!r k9ds ( tissue :]e ! excitation produc$ by /imulus is n exhibit$ 9 a visible =m4 ,9 ord] to /udy ^! we h to use an altoge!r indep5d5t me?od1 ! me?od ( electric response4 ,,footnotes3 #a ,bi$]mann1 ,electro-physiology1 p4#ei4 ,,*apt] ,,ii ,,electric ,,response ,conditions = obta9+ electric response--,me?od ( injury--,curr5t ( injury--,injur$ end1 cuproid3 un9jur$1 z9coid--,curr5t ( response 9 n]ve f m excit$ to less excit$--,difficulties ( pres5t nom5clature--,electric record]--,two types ( response1 positive & negative--,univ]sal applicability ( electric mode ( response--,electric response a measure ( physiological activity--,electric response 9 plants4 ,unlike muscle1 a l5g? ( n]ve1 :5 me*anically or electrically excit$1 does n und]go any visible *ange4 ,t x is ?r[n into an excitatory /ate1 & t x conducts ! excitatory di/urbance1 is %[n h[ev] by ! contraction produc$ 9 an atta*$ piece ( muscle1 :i* s]ves z an indicator4 ,b ! excitatory effect produc$ 9 ! n]ve by /imulus c also be detect$ by an electrical me?od4 ,if an isolat$ piece ( n]ve be tak5 & two contacts be made on its surface by means ( non-pol>isable electrodes at ,a & ,b1 connection be+ made ) a galvanomet]1 no curr5t w be obs]v$1 z bo? ,a & ,b are 9 ! same physico-*emical condition4 ,! two po9ts1 t is to say1 are iso-electric4 ,if n[ ! n]ve be excit$ by /imulus1 simil> di/urbances w be evok$ at bo? ,a & ,b4 ,if1 fur!r1 ^! di/urbances1 rea*+ ,a & ,b almo/ simultane\sly1 cause any electrical *ange1 !n1 simil> *anges tak+ place at bo? po9ts1 & !re be+ ?us no relative diff]5ce betwe5 ! two1 ! galvanomet] w /ill indicate no curr5t4 ,?is null-effect is due to ! balanc+ action ( ,b z aga9/ ,a4 7,see fig4#b1 a47 ,conditions = obta9+ electric response4--,if !n we wi% to detect ! response by means ( ! galvanomet]1 "o means ( do+ s w lie 9 ! abolition ( ?is balance1 :i* may be accompli%$ by mak+ "o ( ! two po9ts1 say ,b1 m or less p]man5tly irresponsive4 ,9 t case1 /imulus w cause great] electrical di/urbance at ! m responsive po9t1 say ,a1 & ?is w be %[n by ! galvanomet] z a curr5t ( response4 ,to make ,b less responsive we may injure x by means ( a cross-sectional cut1 a burn1 or ! action ( /rong *emical reag5ts4 ,illu/ration3 ,,fig4#b4--;,,electric ,,me?od ,,( ,,detect+ ,,n]ve ,,response 7a7 ,iso-electric contacts2 no curr5t 9 ! galvanomet]4 7b7 ,! end ,b injur$2 curr5t ( injury f ,b to ,a3 /imulation gives rise to an action curr5t f ,a to ,b4 7c7 ,non-pol>isable electrode4 ,curr5t ( injury4--,we %all rev]t to ! subject ( electric response2 mean:ile x is necess>y to say a few words reg>d+ ! electric di/urbance caus$ by ! injury itself4 ,s9ce ! physico-*emical conditions ( ! un9jur$ ,a & ! injur$ ,b are n[ no long] ! same1 x foll[s t _! electric conditions h also become diff]5t4 ,!y are no long] iso-electric4 ,!re is ?us a m or less p]man5t or re/+ diff]5ce ( electric pot5tial betwe5 !m4 ,a curr5t--! curr5t ( injury--is f\nd to fl[ 9 ! n]ve1 f ! injur$ to ! un9jur$1 & 9 ! galvanomet]1 ?r\gh ! electrolytic contacts f ! un9jur$ to ! injur$4 ,z long z !re is no fur!r di/urbance ?is curr5t ( injury rema9s approximately con/ant1 & is !re=e sometimes kn[n z '! curr5t ( re/' 7fig4#b1 b74 ,a piece ( liv+ tissue1 unequally injur$ at ! two ends1 is ?us se5 to act l a voltaic elem5t1 comp>able to a copp] & z9c c\ple4 ,z "s confusion has aris51 on ! "q ( :e!r ! injur$ end is l ! z9c or copp] 9 su* a comb9ation1 x w p]haps be well to ent] ^u ?is subject 9 detail4 ,if we take two rods1 ( z9c & copp] respectively1 9 metallic contact1 & fur!r1 if ! po9ts ,a & ,b are connect$ by a /rip ( clo? s moi/5$ ) salt solution1 x w be se5 t we h a complete voltaic elem5t4 ,a curr5t w n[ fl[ f ,b to ,a 9 ! metal 7fig4#c1 a7 & f ,a to ,b ?r\gh ! electrolyte s4 ,or in/ead ( connect+ ,a & ,b by a s+le /rip ( clo? s1 we may connect !m by two /rips ss'1 lead+ to non-pol>isable electrodes ,e,e'4 ,! curr5t w !n be f\nd j ! same z be=e1 i4e4 f ,b to ,a 9 ! metallic "p1 & f ,a ?r\gh ss' to ,b1 ! wire ,w be+ int]pos$1 z x 71 9 ! electrolytic "p ( ! circuit4 ,if n[ a galvanomet] be int]pos$ at ,o1 ! curr5t w fl[ f ,b to ,a ?r\gh ! galvanomet]1 i4e4 f "r to left4 ,b if we int]pose ! galvanomet] 9 ! electrolytic "p ( ! circuit1 t is to say1 at ,w1 ! same curr5t w appe> to fl[ 9 ! opposite direction4 ,9 fig4#c1 c1 ! galvanomet] is s int]pos$1 & 9 ?is case x is to be notic$ t :5 ! curr5t 9 ! galvanomet] fl[s f left to "r1 ! metal connect$ to ! left is z9c4 ,comp>e fig4#c1 d1 :]e ,a,b is a piece ( n]ve ( :i* ! ,b end is injur$4 ,! curr5t 9 ! galvanomet] ?r\gh ! non-pol>isable electrode is f left to "r4 ,! un9jur$ end is !re=e comp>able to ! z9c 9 a voltaic cell 7is z9coid71 ! injur$ be+ copp]-l or cuproid4#b ,illu/ration3 ,,fig4#c4--;,,diagram ,,%[+ ,,! ,,correspond5ce ,,betwe5 ,,injur$ 7,b7 ,,& ,,un9jur$ 7,a7 ,,contacts ,,9 ,,n]ve1 ,,& ,cu ,,& ,zn ,,9 ,a ,,voltaic ,,elem5t ,comp>ison ( 7c7 & 7d7 w %[ t ! injur$ end ( ,b 9 7d7 corresponds ) ! ,cu 9 7c74 ,if ! electrical condition (1 say1 z9c 9 ! voltaic c\ple 7fig4#c1 c7 und]go any *ange 7& ,i %all %[ lat] t ?is c be caus$ by molecul> di/urbance71 !n ! exi/+ diff]5ce ( pot5tial betwe5 ,a & ,b w also und]go v>iation4 ,if = example ! electrical condition ( ,a approa* t ( ,b1 ! pot5tial diff]5ce w und]go a dim9ution1 & ! curr5t hi!rto fl[+ 9 ! circuit w1 z a consequ5ce1 display a dim9ution1 or negative v>iation4 ,action curr5t4--,we h se5 t a curr5t ( injury--sometimes kn[n z 'curr5t ( re/'--fl[s 9 a n]ve f ! injur$ to ! un9jur$1 & t ! injur$ ,b is !n less excitable ?an ! un9jur$ ,a4 ,if n[ ! n]ve be excit$1 !re be+ a great] effect produc$ at ,a1 ! exi/+ diff]5ce ( pot5tial may ?us be r$uc$1 ) a consequ5t dim9ution ( ! curr5t ( injury4 ,dur+ /imulation1 !re=e1 a n]ve exhibits a negative v>iation4 ,we may express ?is 9 a diff]5t way by say+ t a 'curr5t ( action' 0 produc$ 9 response to /imulus1 & act$ 9 an opposite direction to ! curr5t ( injury 7fig4#b1 b74 ,! action curr5t 9 ! n]ve is f ! relatively m excit$ to ! relatively less excit$4 ,difficulties ( pres5t nom5clature4--,we %all deal lat] ) a me?od by :i* a responsive curr5t ( action is obta9$ )\t any antec$5t curr5t ( injury4 ',negative v>iation' has !n no mean+4 ,or1 aga91 a curr5t ( injury may sometimes und]go a *ange ( direction 7see note1 p4#ab74 ,9 view ( ^! consid]ations x is necess>y to h at our disposal o!r =ms ( expression by :i* ! direction ( ! curr5t ( response c /ill be designat$4 ,keep+ 9 t\* ) ! old phraseology1 we might !n call a curr5t 'negative' t fl[$ f ! m excit$ to ! less excit$4 ,or1 be>+ 9 m9d ! fact t an un9jur$ contact acts z ! z9c 9 a voltaic c\ple1 we might call x 'z9coid1' & ! injur$ contact 'cuproid4' ,/imulation ( ! un9jur$ end1 approximat+ x to ! condition ( ! injur$1 might !n be said to induce a cuproid *ange4 ,! electric *ange produc$ 9 a normal n]ve by /imulation may !re=e be express$ by say+ t !re has be5 a negative v>iation1 or t !re 0 a curr5t ( action f ! m excit$ to ! less excit$1 or t /imulation has produc$ a cuproid *ange4 ,! excitation1 or molecul> di/urbance1 produc$ by a /imulus has ?us a concomitant electrical expression4 ,z ! excitatory /ate disappe>s ) ! return ( ! excitable tissue to its orig9al condition1 ! curr5t ( action w gradually disappe>4#c ,! movem5t ( ! galvanomet] ne$le dur+ excitation ( ! tissue ?us indicates a molecul> upset by ! /imulus2 & ! gradual creep+ back ( ! galvanomet] deflection exhibits a molecul> recov]y4 ,?is transitory electrical v>iation con/itutes ! 'response1' & its int5sity v>ies accord+ to t ( ! /imulus4 ,electric record]4--,we h ?us a me?od ( obta9+ curves ( response electrically4 ,aft] all1 x is n ess5tially v diff]5t f ! me*anical me?od4 ,9 ?is case we use a magnetic lev] 7fig4#d1 a71 ! ne$le ( ! galvanomet]1 :i* is deflect$ by ! electromagnetic pull ( ! curr5t1 g5]at$ "u ! action ( /imulus1 j z ! me*anical lev] 0 deflect$ by ! me*anical pull ( ! muscle contract+ "u /imulus4 ,! accompany+ diagram 7fig4#d1 b7 %[s h[1 "u ! action ( /imulus1 ! curr5t ( re/ und]goes a transitory dim9ution1 & h[ on ! cessation ( /imulus !re is gradual recov]y ( ! tissue1 z exhibit$ 9 ! return ( ! galvanomet] ne$le to its orig9al position4 ,illu/ration3 ,,fig4#d4--;,,electric ,,record] 7a7 ,m muscle2 ,a un9jur$1 ,b injur$ ends4 ,e,e' non-pol>is+ electrodes connect+ ,a & ,b ) galvanomet] ,g4 ,/imulus produces 'negative v>iation' ( curr5t ( re/4 ,index connect$ ) galvanomet] ne$le records curve on travell+ pap] 79 practice1 mov+ galvanomet] spot ( light traces curve on photographic plate74 ,ris+ "p ( curve %[s effect ( /imulus2 desc5d+ "p1 recov]y4 7b7 ,o is ! z]o position ( ! galvanomet]2 injury produces a deflection ,a,b2 /imulus dim9i%es ?is deflection to ,c2 ,c,d is ! recov]y4 ,two types ( response--positive & negative4--,x may "h be add$ t ?\gh /imulus 9 g5]al produces a dim9ution ( curr5t ( re/1 or a negative v>iation 7e4g4 muscles & n]ves71 yet1 9 c]ta9 cases1 !re is an increase1 or positive v>iation4 ,?is is se5 9 ! response ( ! ret9a to light4 ,aga91 a tissue :i* normally gives a negative v>iation may und]go molecul> *anges1 aft] :i* x gives a positive v>iation4 ,?us ,dr4,wall] f9ds t :]eas fre% n]ve always gives negative v>iation1 /ale n]ve sometimes gives positive2 & t ret9a1 :i* :5 fre% gives positive1 :5 /ale1 exhibits negative v>iation4 ,! foll[+ is a tabul> /atem5t ( ! two types ( response3 ,i4 ,negative v>iation4--,action curr5t f m excit$ to less excit$--cuproid *ange 9 ! excit$--e4g4 fre% muscle & n]ve1 /ale ret9a4 ,,ii4 ,positive v>iation4--,action curr5t f less excit$ to m excit$--z9coid *ange 9 ! excit$--e4g4 /ale n]ve1 fre% ret9a4#d ,f ?is x w be se5 t x is ! fact ( ! electrical response ( liv+ sub/ances to /imulus t is ( ess5tial importance1 ! sign plus or m9us be+ a m9or consid]ation4 ,univ]sal applicability ( ! electrical mode ( response4--,?is mode ( obta9+ electrical response is applicable to all liv+ tissues1 & 9 cases l t ( muscle1 :]e me*anical response is also available1 x is f\nd t ! electrical & me*anical records are practically id5tical4 ,! two response-curves se5 9 ! accompany+ diagram 7fig4#e71 & tak5 f ! same muscle by ! two me?ods simultane\sly1 cle>ly exhibit ?is4 ,?us we see t electrical response c n only take ! place ( ! me*anical record1 b has ! fur!r advantage ( be+ applicable 9 cases :]e ! latt] _c be us$4 ,electrical response3 ,a measure ( physiological activity4--,^! electrical *anges are reg>d$ z physiological1 or *>act]i/ic ( liv+ tissue1 = any conditions :i* enhance physiological activity also1 p>i passu1 increase _! int5sity4 ,aga91 :5 ! tissue is kill$ by poison1 electrical response disappe>s1 ! tissue pass+ into an irresponsive condition4 ,an/hetics1 l *lor(orm1 gradually dim9i%1 & f9ally altoge!r aboli%1 electrical response4 ,illu/ration3 ,,fig4#e4--,,simultane\s ,,record ,,( ,,! ,,me*anical 7,m7 ,,& 7,e7 ,,electrical ,,responses ,,( ,,! ,,muscle ,,( ,,frog4 7,,wall]47 ,f ^! obs]v$ facts--t liv+ tissue gives response :ile a tissue t has be5 kill$ does n--x is conclud$ t ! ph5om5on ( response is peculi> to liv+ organisms4#e ,! response ph5om5a t we h be5 /udy+ are !re=e consid]$ z due to "s unkn[n1 sup]-physical 'vital' =ce & are ?us relegat$ to a region beyond physical inquiry4 ,x may1 h[ev]1 be t ?is limitation is n ju/ifi$1 & surely1 at lea/ until we h explor$ ! :ole range ( physical action1 x _c be ass]t$ def9itely t a p>ticul> class ( ph5om5a is by its v nature outside t category4 ,electric response 9 plants4--,b be=e we proce$ to ! inquiry z to :e!r ^! responses are or are n due to "s physical prop]ty ( matt]1 & are to be met ) ev5 9 inorganic sub/ances1 x w p]haps be advisable to see :e!r !y are n p>allel$ by ph5om5a 9 ! transitional _w ( plants4 ,we %all ?us pass f a /udy ( response 9 highly complex animal tissues to ^? giv5 "u simpl] vital conditions4 ,electric response has be5 f\nd by ,munck1 ,burdon-,s&]son1 & o!rs to occur 9 s5sitive plants4 ,b x w\ld be int]e/+ to "k :e!r ^! responses 7 conf9$ to plants :i* exhibit su* rem>kable me*anical movem5ts1 & :e!r !y c\ld n also be obta9$ f ord9>y plants :]e visible movem5ts are completely abs5t4 ,9 ?is connection1 ,kunkel obs]v$ electrical *anges 9 association ) ! injury or flexion ( /ems ( ord9>y plants4#f ,my own attempt1 h[ev]1 0 direct$1 n t[>ds ! obta9+ ( a m]e qualitative response1 b r to ! det]m9ation ( :e!r ?r\gh\t ! :ole range ( response ph5om5a a p>allelism betwe5 animal & vegetable c\ld be detect$4 ,t is to say1 ,i desir$ to "k1 ) reg>d to plants1 :at 0 ! relation betwe5 int5sity ( /imulus & ! correspond+ response2 :at 7 ! effects ( sup]position ( /imuli2 :e!r fatigue 0 pres5t1 & 9 :at mann] x influ5c$ response2 :at 7 ! effects ( extremes ( temp]ature on ! response2 &1 la/ly1 if *emical reag5ts c\ld ex]cise any influ5ce 9 ! modification ( plant response1 z /imulat+1 an/hetic1 & poison\s drugs h be5 f\nd to d ) n]ve & muscle4 ,if x c\ld be prov$ t ! electric response s]v$ z a fai?ful index ( ! physiological activity ( plants1 x w\ld !n be possible successfully to attack _m problems 9 plant physiology1 ! solution ( :i* at pres5t (f]s _m exp]im5tal difficulties4 ,) animal tissues1 exp]im5ts h to be c>ri$ on "u _m great & unavoidable difficulties4 ,! isolat$ tissue1 = example1 is subject to unkn[n *anges insep>able f ! rapid approa* ( dea?4 ,plants1 h[ev]1 (f] a great advantage 9 ?is respect1 = !y ma9ta9 _! vitality unimpair$ dur+ a v great l5g? ( "t4 ,9 animal tissues1 aga91 ! vital conditions !mselves are highly complex4 ,^? ess5tial factors :i* modify response c1 !re=e1 be bett] det]m9$ "u ! simpl] conditions :i* obta9 9 vegetable life4 ,9 ! succe$+ *apt]s x w be %[n t ! response ph5om5a are exhibit$ n only by plants b by inorganic sub/ances z well1 & t ! responses are modifi$ by v>i\s conditions 9 exactly ! same mann] z ^? ( animal tissues4 ,9 ord] to %[ h[ /rik+ are ^! simil>ities1 ,i %all = comp>ison place side by side ! responses ( animal tissues & ^? ,i h obta9$ ) plants & inorganic sub/ances4 ,= ! electric response 9 animal tissues1 ,i %all take ! late/ & mo/ complete examples f ! records made by ,dr4,wall]4 ,b be=e we c obta9 satisfactory & conclusive results reg>d+ plant response1 _m exp]im5tal difficulties w h to be surm\nt$4 ,i %all n[ describe h[ ?is has be5 accompli%$4#g ,,footnotes3 #b ,9 "s physiological text-books mu* wrong inf]5ce has be5 made1 bas$ on ! supposition t ! injur$ end is z9c-l4 #c ',! excit+ cause is able to produce a p>ticul> molecul> re>rangem5t 9 ! n]ve2 ?is con/itutes ! /ate ( excitation & is accompani$ by local electrical *anges z an asc]ta9$ physical concomitant4' ',! excitatory /ate evok$ by /imulus manife/s itself 9 n]ve fibres by ,e4,m4 *anges1 & z f> z our pres5t k goes by ^! only4 ,! conception ( su* an excitable liv+ tissue z n]ve implies t ( a molecul> /ate :i* is 9 /able equilibrium4 ,?is equilibrium c be readily upset by an ext]nal ag5cy1 ! /imulus1 b ! t]m /able expresses ! fact t a *ange 9 any direction mu/ be succe$$ by "o ( opposite "*1 ?is be+ ! return ( ! liv+ /ructure to its previ\s /ate4 ,?us ! electrical manife/ation ( ! excitatory /ate is "o ^: duration dep5ds ^u ! "t dur+ :i* ! ext]nal ag5t is able to upset & reta9 9 a new poise ! liv+ equilibrium1 & if ?is is extremely brief1 !n ! recoil ( ! tissue causes su* manife/ation to be itself ( v %ort duration4'--,text-book ( ,physiology1 ed4 by ,s*f]1 ii4#dec4 #d ,i %all "h m5tion briefly "o complication t might arise f reg>d+ ! curr5t ( injury z ! curr5t ( ref]5ce1 & designat+ ! response curr5t ei!r positive or negative 9 relation to x4 ,if ?is curr5t ( injury rema9$ always inv>iable 9 direction--t is to say1 f ! injur$ to ! un9jur$--!re w\ld be no s\rce ( unc]ta9ty4 ,b x is (t5 f\nd1 = example 9 ! ret9a1 t ! curr5t ( injury und]goes a rev]sal1 or is rev]s$ f ! beg9n+4 ,t is to say1 ! direction is n[ f ! un9jur$ to ! injur$1 in/ead ( ! opposite4 ,confusion is ?us v apt to arise4 ,no su* misund]/&+ c h[ev] occur if we call ! curr5t ( response t[>ds ! m excit$ positive1 & t[>ds ! less excit$ negative4 #e ',! ,electrical ,sign ( ,life4444 ,an isolat$ muscle gives sign ( life by contract+ :5 /imulat$4444 ,an ord9>y n]ve1 normally connect$ ) its t]m9al organs1 gives sign ( life by means ( muscle1 :i* by direct or reflex pa? is set 9 motion :5 ! n]ve trunk is /imulat$4 ,b su* n]ve sep>at$ f its natural t]m9i1 isolat$ f ! re/ ( ! organism1 gives no sign ( life :5 excit$1 ei!r 9 ! %ape ( *emical or ( !rmic *anges1 & x is only by means ( an electrical *ange t we c asc]ta9 :e!r or no x is alive4444 ,! mo/ g5]al & mo/ delicate sign ( life is !n ! electrical response4'--,wall]1 9 ,bra91 pp4 #c & #d4 ,spr+ #aijj4 #f ,kunkel ?\ght ! electric di/urbance to be due to movem5t ( wat] ?r\gh ! tissue4 ,x w be %[n t ?is explanation is inadequate4 #g ,my assi/ant ,mr4,j4 ,bull has r5d]$ me v effici5t help 9 ^! exp]im5ts4 ,,*apt] ,,iii ,,electric ,,response ,,9 ,,plants--,,me?od ,,( ,,negative ,,v>iation ,negative v>iation--,response record]--,photographic record]--,comp5sator--,means ( graduat+ int5sity ( /imulus--,spr+-tapp] & torsional vibrator--,int5sity ( /imulus dep5d5t on amplitude ( vibration--,effectiv5ess ( /imulus dep5d5t on rapidity also4 ,i %all fir/ proce$ to %[ t an electric response is evok$ 9 plants "u /imulation4#h ,9 exp]im5ts = ! exhibition ( electric response x is pref]able to use a non-electrical =m ( /imulus1 = !re is !n a c]ta9ty t ! obs]v$ response is entirely due to reaction f /imulus1 & n1 z might be ! case ) electric /imulus1 to m]e escape ( /imulat+ curr5t ?r\gh ! tissue4 ,= ?is reason1 ! me*anical =m ( /imulation is ! mo/ suitable4 ,i f9d t all p>ts ( ! liv+ plant give electric response to a great] or less ext5t4 ,"s1 h[ev]1 give /rong] response ?an o!rs4 ,9 fav\rable cases1 we may h an ,e4,m4 v>iation z high z #avolt4 ,x mu/ h[ev] be rememb]$ t ! response1 be+ a function ( physiological activity ( ! plant1 is liable to und]go *anges at diff]5t seasons ( ! ye>4 ,ea* plant has its p>ticul> season ( maximum responsiv5ess4 ,! leaf-/alk ( horse-*e/nut1 = example1 exhibits fairly /rong response 9 spr+ & summ]1 b on ! approa* ( autumn x und]goes dim9ution4 ,i give "h a li/ ( specim5s :i* w be f\nd to exhibit fairly good response3 ,root4--,c>rot 7,daucus ,c>ota71 radi% 7,raphanus sativus74 ,/em4--,g]anium 7,pel>gonium71 v9e 7,vitis v9if]a74 ,leaf-/alk4--,horse-*e/nut 7sculus ,hippoca/anum71 turnip 7,brassica ,napus71 caulifl[] 7,brassica ol]acea71 cel]y 7,apium graveol5s71 ,eu*>is lily 7,eu*>is amazonica74 ,fl[]-/alk4--,arum lily 7,ri*>dia africana74 ,fruit4--,egg-plant 7,solanum ,melong5a74 ,negative v>iation4--,tak+ ! leaf-/alk ( turnip we kill an area on its surface1 say ,b1 by ! application ( a few drops ( /rong pota%1 ! area at ,a be+ left un9jur$4 ,a curr5t is n[ obs]v$ to fl[1 9 ! /alk1 f ! injur$ ,b to ! un9jur$ ,a1 z 0 f\nd to be ! case 9 ! animal tissue4 ,! pot5tial diff]5ce dep5ds on ! condition ( ! plant1 & ! season 9 :i* x may h be5 ga!r$4 ,9 ! exp]im5t "h describ$ 7fig4#f1 a7 its value 0 #acvolt4 ,illu/ration3 ,,fig4#f4--7;a7 ,,exp]im5t ,,= ,,exhibit+ ,,electric ,,response ,,9 ,,plants ,,by ,,me?od ,,( ,,negative ,,v>iation4 7b7 ,,responses ,,9 ,,leaf-,,/alk ,,( ,,turnip ,,to ,,/imuli ,,( ,,two ,,successive ,,taps1 ,,! ,,second ,,be+ ,,/rong]4 ,a & ,b contacts are ab\t #b;cm4 ap>t1 ,b be+ injur$4 ,plant is /imulat$ by a tap betwe5 ,a & ,b4 ,/imulus acts on bo? ,a & ,b1 b ow+ to injury ( ,b1 effect at ,a is /rong] & a negative v>iation due to diff]5tial action occurs4 ,a %>p tap 0 n[ giv5 to ! /alk1 & a sudd5 dim9ution1 or negative v>iation1 ( curr5t occurr$1 ! re/+ pot5tial diff]5ce be+ decreas$ by #jbfvolt4 ,a second & /rong] tap produc$ a second response1 caus+ a great] dim9ution ( ,p4,d4 by #jdgvolt 7fig4#f1 b74 ,! accompany+ figure is a photographic record ( ano!r set ( response-curves 7fig4#g74 ,! fir/ ?ree responses are = a giv5 int5sity ( /imulus1 & ! next six 9 response to /imulus ne>ly twice z /rong4 ,x w be notic$ t fatigue is exhibit$ 9 ^! responses4 ,o!r exp]im5ts w be describ$ 9 ! next *apt] :i* %[ conclusively t ! response 0 n due to any accid5tal circum/ance b 0 a direct result ( /imulation4 ,b ,i %all fir/ discuss ! exp]im5tal arrangem5ts & me?od ( obta9+ ^! graphic records4 ,illu/ration3 ,,fig4#g4--,,record ,,( ,,responses ,,9 ,,plant 7,,leaf-,,/alk ,,( ,,caulifl[]7 ,,by ,,me?od ,,( ,,negative ,,v>iation ,! fir/ ?ree records are = /imulus int5sity #a2 ! next six are = int5sity twice z /rong2 ! successive responses exhibit fatigue4 ,! v]tical l9e to ! left repres5ts #avolt4 ,! record is to be read f "r to left4 ,response record]4--,! galvanomet] us$ is a s5sitive dead-beat ,d',arsonval4 ,! p]iod ( complete sw+ ( ! coil "u exp]im5tal conditions is ab\t #aaseconds4 ,a curr5t ( #aj-i;amp]e produces a deflection ( #amm4 at a di/ance ( #ametre4 ,= a quick & accurate me?od ( obta9+ ! records1 ,i devis$ ! foll[+ =m ( response record]4 ,! curves are obta9$ directly1 by trac+ ! excursion ( ! galvanomet] spot ( light on a revolv+ drum 7fig4#h74 ,! drum1 on :i* is wrapp$ ! pap] = receiv+ ! record1 is driv5 by clockwork4 ,diff]5t spe$s ( revolution c be giv5 to x by adju/m5t ( ! clock-gov]nor1 or by *ang+ ! size ( ! driv+-:eel4 ,! galvanomet] spot is ?r[n d[n on ! drum by ! incl9$ mirror ,m4 ,! galvanomet] deflection takes place at "r angles to ! motion ( ! pap]4 ,a /ylographic p5 atta*$ to a c>ri] re/s on ! writ+ surface4 ,! c>ri] slides ov] a rod p>allel to ! drum4 ,z has be5 said be=e1 ! galvanomet] deflection takes place p>allel to ! drum1 & z long z ! plant re/s un/imulat$1 ! p51 rema9+ co9cid5t ) ! /ation>y galvanomet] spot on ! revolv+ pap]1 describes a /raight l9e4 ,if1 on /imulation1 we trace ! result+ excursion ( ! spot ( light1 by mov+ ! c>ri] :i* holds ! p51 ! ris+ portion ( ! response-curve w be obta9$4 ,! galvanomet] spot w !n return m or less gradually to its orig9al position1 & t "p ( ! curve :i* is trac$ dur+ ! process con/itutes ! recov]y4 ,! ord9ate 9 ^! curves repres5ts ! ,e4,m4 v>iation1 & ! abscissa ! "t4 ,illu/ration3 ,,fig4#h4--,,response ,,record] ,we c calibrate ! value ( ! deflection by apply+ a kn[n ,e4,m4,f4 to ! circuit f a comp5sator1 & not+ ! deflection :i* results4 ,! spe$ ( ! clock is previ\sly adju/$ s t ! record+ surface moves exactly ?r\gh1 say1 "o in* a m9ute4 ,( c\rse ?is spe$ c be increas$ to suit ! p>ticul> exp]im5t1 & 9 "s x is z high z six in*es a m9ute4 ,9 ?is simple mann] v accurate records may be made4 ,x has ! additional advantage t "o is able at once to see :e!r ! specim5 is suitable = ! purpose ( inve/igation4 ,a l>ge numb] ( records might be tak5 by ?is means 9 a comp>atively %ort "t4 ,photographic record]4--,or ! records may be made photographically4 ,a clockwork arrangem5t moves a photographic plate at a kn[n uni=m rate1 & a curve is trac$ on ! plate by ! mov+ spot ( light4 ,all ! records t w be giv5 are accurate reproductions ( ^? obta9$ by "o ( ^! two me?ods4 ,photographic records are reproduc$ 9 :ite aga9/ a black backgr\nd4 ,comp5sator4--,z ! responses are on v>iation ( curr5t ( injury1 & z ! curr5t ( injury may be /rong1 & ?r[ ! spot ( light beyond ! record+ surface1 a pot5tiomet] balanc+ arrangem5t may be us$ 7fig4#i71 by :i* ! ,p4,d4 due to injury is exactly comp5sat$2 ,e4,m4 v>iations produc$ by /imulus are !n tak5 9 ! usual mann]4 ,?is comp5sat+ arrangem5t is also helpful1 z has be5 said be=e1 = calibrat+ ! ,e4,m4 value ( ! deflection4 ,illu/ration3 ,,fig4#i4--,,! ,,comp5sator ,a,b is a /ret*$ wire ) add$ resi/ances ,r & ,r'4 ,s is a /orage cell4 ,:5 ! key ,k is turn$ to ! "r "o scale division #jjavolt1 :5 turn$ to ! left "o scale division #javolt4 ,p is ! plant4 ,means ( graduat+ ! int5sity ( /imulus4--,"o ( ! necessities 9 connection ) quantitative measurem5ts is to be c]ta9 t ! int5sity ( successive /imuli is 7#a7 con/ant1 or 7#b7 capable ( gradual increase by kn[n am\nts4 ,no two taps giv5 by ! h& c be made exactly alike4 ,i h !re=e devis$ ! two foll[+ me?ods ( /imulation1 :i* h be5 f\nd to act satisfactorily4 ,illu/ration3 ,,fig4#aj4--,,! ,,spr+-,,tapp] ,! spr+-tapp]4--,?is consi/s 7fig4#aj7 ( ! spr+ prop] 7,s71 ! atta*$ rod 7,r7 c>ry+ at its end ! tapp+-head 7,t74 ,a project+ rod--! lift] 7,l7--passes ?r\gh ,s,r4 ,x is provid$ ) a screw-?read1 by means ( :i* its l5g?1 project+ d[nw>ds1 is regulat$4 ,?is fact1 z we %all see1 is made to det]m9e ! height ( ! /roke4 7,c7 is a cog:eel4 ,z "o ( ! spokes ( ! cog:eel is rotat$ pa/ 7,l71 ! spr+ is lift$ & releas$1 & 7,t7 deliv]s a %>p tap4 ,! height ( ! lift1 & !re=e ! int5sity ( ! /roke1 is measur$ by means ( a graduat$ scale4 ,we c increase ! int5sity ( ! /roke ?r\gh a wide range 7#a7 by increas+ ! project+ l5g? ( ! lift]1 & 7#b7 by %ort5+ ! l5g? ( spr+ by a slid+ cat*4 ,we may give isolat$ s+le taps or sup]pose a s]ies 9 rapid succession accord+ z ! :eel is rotat$ sl[ or fa/4 ,! only disadvantage ( ! tapp+ me?od ( /imulation is t 9 long-cont9u$ exp]im5t ! po9t /ruck is liable to be injur$4 ,! vibrational mode ( /imulation to be pres5tly describ$ lab\rs "u no su* disadvantage4 ,! electric tapp]4--,in/ead ( ! simple me*anical tapp]1 an electromagnetic tapp] may be us$4 ,illu/ration3 ,,fig4#aa4--,,! ,,torsional ,,vibrator ,plant ,p is securely held by a vice ,v4 ,! two ends are clamp$ by hold]s ,c,c'4 ,by means ( h&les ,h,h'1 torsional vibration may be imp>t$ to ei!r ! end ,a or end ,b ( ! plant4 ,! end view 7b7 %[s h[ ! amplitude ( vibration is pr$et]m9$ by means ( movable /ops ,s,s'4 ,vibrational /imulus4--,i f9d t torsional vibration af=ds ano!r v effective me?od ( /imulation 7fig4#aa74 ,! plant-/alk may be fix$ 9 a vice 7,v71 ! free ends be+ held 9 tubes 7,c,c'71 provid$ ) ?ree clamp+ jaws4 ,a rapid torsional vibration#i may n[ be imp>t$ to ! /alk by means ( ! h&le 7,h74 ,! amplitude ( vibration1 :i* det]m9es ! int5sity ( /imulus1 c be accurately measur$ by ! graduat$ circle4 ,! amplitude ( vibration may be pr$et]m9$ by means ( ! slid+ /ops 7,s,s'74 ,int5sity ( /imulus dep5d5t on amplitude ( vibration4--,i %all n[ describe an exp]im5t :i* %[s t torsional vibration is z effective z /imulation by taps1 & t its /imulat+ int5sity increases1 l5g? ( /alk be+ con/ant1 ) amplitude ( vibration4 ,x is ( c\rse obvi\s t if ! l5g? ( ! specim5 be d\bl$1 ! vibration1 9 ord] to produce ! same effect1 mu/ be ?r\gh twice ! angle4 ,i took a leaf-/alk ( turnip & fix$ x 9 ! torsional vibrator4 ,i !n took record ( responses to two successive taps1 ! int5sity ( "o be+ ne>ly d\ble t ( ! o!r4 ,hav+ done ?is1 ,i appli$ to ! same /alk two successive torsional vibrations ( #de & #fg respectively4 ,^! successive responses to taps & torsional vibrations are giv5 9 fig4#ab1 & f !m x w be se5 t ^! two modes ( /imulation may be us$ indiff]5tly1 ) equal effect4 ,! vibrational me?od has ! advantage ov] tapp+1 t1 :ile ) ! latt] ! /imulus is some:at localis$1 ) vibration ! tissue subject$ to /imulus is uni=mly /imulat$ ?r\gh\t its l5g?4 ,illu/ration3 ,,fig4#ab4--,,response ,,9 ,,plant ,,to ,,me*anical ,,tap ,,or ,,vibration ,! end ,b is injur$4 ,a tap 0 giv5 betwe5 ,a & ,b & ?is gave ! response-curve a4 ,a /rong] tap gave ! response b4 ,by means ( ! h&le ,h1 a torsional vibration ( #de 0 n[ imp>t$1 ?is gave ! response c4 ,vibration ?r\gh #fg gave d4 ,effectiv5ess ( /imulus dep5d5t on rapidity also4 ,9 ord] t successive /imuli may be equally effective ano!r po9t has to be borne 9 m9d4 ,9 all cases ( /imulation ( liv+ tissue x is f\nd t ! effectiv5ess ( a /imulus to ar\se response dep5ds on ! rapidity ( ! onset ( ! di/urbance4 ,x is ?us f\nd t ! /imulus ( ! 'break' induction %ock1 on a muscle = example1 is m effective1 by reason ( its great] rapidity1 ?an ! 'make' %ock4 ,s also ) ! torsional vibrations ( plants1 ,i f9d response dep5d+ on ! quickness ) :i* ! vibration is effect$4 ,i give bel[ records ( successive /imuli1 giv5 by vibrations ?r\gh ! same amplitude1 b deliv]$ ) increas+ rapidity 7fig4#ac74 ,illu/ration3 ,,fig4#ac4--;,,influ5ce ,,( ,,sudd5ness ,,on ,,! ,,effici5cy ,,( ,,/imulus ,! curves a1 b1 c1 d1 are responses to vibrations ( ! same amplitude1 #cj4 ,9 a ! vibration 0 v sl[2 9 b x 0 less sl[2 x 0 rapid 9 c1 & v rapid 9 d4 ,?us if we wi% to ma9ta9 ! effective int5sity ( /imulus con/ant we mu/ meet two conditions3 7#a7 ,! amplitude ( vibration mu/ be kept ! same4 ,?is is done by means ( ! graduat$ circle4 7#b7 ,! vibration p]iod mu/ be kept ! same4 ,) a little practice1 ?is requirem5t is easily fulfill$4 ,! uni=mity ( /imulation :i* is ?us atta9$ solves ! great difficulty ( obta9+ reliable quantitative values1 by ^: means alone c rigor\s demon/ration ( ! ph5om5a we are /udy+ become possible4 ,,footnotes3 #h ,a prelim9>y acc\nt ( ,electric ,response 9 ,plants 0 giv5 at ! end ( my pap] on ',electric ,response ( ,inorganic ,sub/ances' read be=e ! ,royal ,society on ,june#f1 #aija2 also at ! ,friday ,ev5+ ,disc\rse1 ,royal ,in/itution1 ,may#aj1 #aija4 ,a m complete acc\nt is giv5 9 my pap] on ',electric ,response 9 ,ord9>y ,plants "u ,me*anical ,/imulus' read be=e ! ,l9nean ,society ,m>*#bj1 #aijb4 ,i ?ank ! ,royal ,society & ! ,l9nean ,society = p]mission to reproduce "s ( my diagrams publi%$ 9 _! ,proce$+s4--,j4,c4,b4 #i ,by ?is is meant a rapid to-&-fro or complete vibration4 ,9 ord] t successive responses %\ld be uni=m x is ess5tial t !re %\ld be no resultant twi/1 i4e4 ! plant at ! end ( vibration %\ld be 9 exactly ! same condition z at ! beg9n+4 ,,*apt] ,,iv ,,electric ,,response ,,9 ,,plants--,,block ,,me?od ,me?od ( block--,advantages ( block me?od--,plant response a physiological ph5om5on--,abolition ( response by an/hetics & poisons--,abolition ( response :5 plant is kill$ by hot wat]4 ,i %all n[ proce$ to describe ano!r & indep5d5t me?od :i* ,i devis$ = obta9+ plant response4 ,x has ! advantage ( (f]+ u a complem5t>y means ( v]ify+ ! results f\nd by ! me?od ( negative v>iation4 ,z x is also1 9 itself1 = reasons :i* w be %[n lat]1 a m p]fect mode ( inquiry1 x enables u to inve/igate problems :i* w\ld o!rwise h be5 difficult to attempt4 ,:5 electrolytic contacts are made on ! un9jur$ surfaces ( ! /alk at ,a & ,b1 ! two po9ts1 be+ practically simil> 9 e way1 are iso-electric1 & little or no curr5t w fl[ 9 ! galvanomet]4 ,if n[ ! :ole /alk be uni=mly /imulat$1 & if bo? ends ,a & ,b be equally excit$ at ! same mom5t1 x is cle> t !re w /ill be no responsive curr5t1 ow+ to balanc+ action at ! two ends4 ,?is difficulty z reg>ds ! obta9+ ( response 0 ov]come 9 ! me?od ( negative v>iation1 :]e ! excitability ( "o end 0 depress$ by *emical reag5ts or injury1 or aboli%$ by excessive temp]ature4 ,on /imulat+ ! /alk !re 0 produc$ a great] excitation at ,a ?an at ,b1 & a curr5t ( action 0 !n obs]v$ to fl[ 9 ! /alk f ! m excit$ ,a to ! less excit$ ,b 7fig4#f74 ,b we c cause ?is diff]5tial action to become evid5t by ano!r means4 ,= example1 if we produce a block1 by clamp+ at ,c betwe5 ,a & ,b 7fig4#ad1 a71 s t ! di/urbance made at ,a by tapp+ or vibration is prev5t$ f rea*+ ,b1 we %all !n h ,a ?r[n into a relatively great] excitatory condition ?an ,b4 ,x w n[ be f\nd t a curr5t ( action fl[s 9 ! /alk f ,a to ,b1 t is to say1 f ! excit$ to ! less excit$4 ,:5 ! ,b end is /imulat$1 !re w be a rev]se curr5t 7fig4#ad1 b74 ,illu/ration3 ,,fig4#ad4--,,! ,,me?od ,,( ,,block 7a7 ,! plant is clamp$ at ,c1 betwe5 ,a & ,b4 7b7 ,responses obta9$ by alt]nately /imulat+ ! two ends4 ,/imulation ( ,a produces upw>d response2 ( ,b gives d[nw>d response4 ,we h 9 ?is me?od a great advantage ov] t ( negative v>iation1 = we c always v]ify any set ( results by mak+ corroborative rev]sal exp]im5ts4 ,by ! me?od ( injury aga91 "o end is made initially abnormal1 i4e4 diff]5t f ! condition :i* x ma9ta9s :5 intact4 ,fur!r1 inevitable *anges w proce$ unequally at ! injur$ & un9jur$ ends1 & ! conditions ( ! exp]im5t may ?us und]go unkn[n v>iations4 ,b by ! block me?od :i* has j be5 describ$1 !re is no injury1 ! plant is normal ?r\gh\t1 & any physiological *ange 7:i* 9 plants w be exce$+ly small dur+ ! "t ( ! exp]im5t7 w affect x z a :ole4 ,illu/ration3 ,,fig4#ae4--,,response ,,9 ,,plant 7,,f ,,! ,,/imulat$ ,a ,,to ,,un/imulat$ ,b7 ,,completely ,,imm]s$ ,,"u ,,wat] ,! leaf-/alk is clamp$ securely 9 ! middle ) ! cork ,c1 inside ! tube ,t1 :i* is fill$ ) wat]1 ! plant be+ completely imm]s$4 ,moi/5$ ?reads 9 connection ) ! two non-pol>isable electrodes are l$ to ! side tubes tt'4 ,"o end ( ! /alk is held 9 ebonite =ceps & vibrat$4 ,a curr5t ( response is f\nd to fl[ 9 ! /alk f ! excit$ ,a to ! unexcit$ ,b1 & outside1 ?r\gh ! liquid1 f ,b to ,a4 ,a portion ( ?is curr5t1 fl[+ ?r\gh ! side tubes tt'1 produces deflection 9 ! galvanomet]4 ,plant response a physiological or vital response4--,i n[ proce$ to a demon/ration ( ! fact t :atev] be ! me*anism by :i* !y are br\ght ab\t1 ^! plant responses are physiological 9 _! "*4 ,z ! inve/igations describ$ 9 ! next few *apt]s w %[1 !y furni% an accurate index ( physiological activity4 ,= x w be f\nd t1 o!r ?+s be+ equal1 :atev] t5ds to exalt or depress ! vitality ( ! plant t5ds also to increase or dim9i% its electric response4 ,^! ,e4,m4 effects are well m>k$1 & atta9 consid]able value1 ris+ sometimes1 z has be5 said be=e1 to z mu* z #avolt or m4 ,!y are proportional to ! int5sity ( /imulus4 ,x ne$ h>dly be add$ t special precautions are tak5 to avoid %ift+ ( contacts4 ,v>iation ( contact1 h[ev]1 c\ld n 9 any case acc\nt = repeat$ transi5t responses to repeat$ /imuli1 :5 contact is made on iso-electric surfaces4 ,nor c\ld x 9 any way expla9 ! rev]sible nature ( ^! responses1 :5 ,a & ,b are /imulat$ alt]nately4 ,^! responses are obta9$ 9 ! plants ev5 :5 completely imm]s$ 9 wat]1 z 9 ! exp]im5tal arrangem5t 7fig4#ae74 ,x w be se5 t 9 ?is case1 :]e !re c\ld be no possibility ( %ift+ ( contact1 or v>iation ( surface1 !re is /ill ! usual curr5t ( response4 ,i %all describe "h a few crucial exp]im5ts only1 9 pro( ( ! physiological "* ( electric response4 ,! te/ appli$ by physiologi/s1 9 ord] to discrim9ate z to ! physiological nature ( response1 consi/s 9 f9d+ out :e!r ! response is dim9i%$ or aboli%$ by ! action ( an/hetics1 poisons1 & excessively high temp]ature1 :i* are kn[n to depress or de/roy vitality4 ,i %all !re=e apply ^! same te/s to plant responses4 ,effect ( an/hetics & poisons4--,ord9>y an/hetics1 l *lor(orm1 & poisons1 l m]curic *loride1 are kn[n to produce a pr(\nd depression or aboli% all signs ( response 9 ! liv+ tissue4 ,= ! purpose ( exp]im5t1 ,i took two gr\ps ( /alks1 ) leaves atta*$1 exactly simil> to ea* o!r 9 e respect4 ,9 ord] t ! leaf-/alks might absorb *lor(orm ,i dipp$ _! cut ends 9 *lor(orm-wat]1 a c]ta9 am\nt ( :i* !y absorb$1 ! process be+ help$ by ! transpiration f ! leaves4 ,! second gr\p ( /alks 0 plac$ simply 9 wat]1 9 ord] to s]ve = control exp]im5t4 ,! n>cotic action ( *lor(orm1 f9ally culm9at+ 9 dea?1 soon became visually evid5t4 ,! leaves began to droop1 a peculi> dea?-discol\ration began to spread f ! mid rib along ! v5ation ( ! leaves4 ,ano!r peculi>ity 0 also obs]v$4 ,! aphides fe$+ on ! leaves di$ ev5 be=e ! appe>ance ( ! discol\r$ pat*es1 :]eas on ! leaves ( ! /alks plac$ 9 wat] ^! little creatures ma9ta9$ _! accu/om$ activity1 nor did any discol\ration occur4 ,9 ord] to /udy ! effect ( poison1 ano!r set 0 plac$ 9 wat] conta9+ a small quantity ( m]curic *loride4 ,! leaves "h und]w5t ! same *ange ( appe>ance1 & ! aphides met ) ! same untimely fate1 z 9 ! case ( ^? subject$ to ! action ( *lor(orm4 ,!re 0 h>dly any visible *ange 9 ! appe>ance ( ! /alks !mselves1 :i* 7 to all out] seem+ z liv+ z ev]1 indications ( dea? be+ app>5t only on ! leaf surfaces4 ,i give bel[ ! results ( sev]al sets ( exp]im5ts1 f :i* x w\ld appe> t :]eas !re 0 /rong normal response 9 ! gr\p ( /alks kept 9 wat]1 !re 0 practically a total abolition ( all response 9 ^? an/hetis$ or poison$4 ,exp]im5ts on ! effect ( an/hetics & poisons4 ,a bat* ( t5 leaf-/alks ( plane-tree 0 plac$ ) ! cut ends 9 wat]1 & leaves 9 air2 an equal numb] 0 imm]s$ 9 *lor(orm-wat]2 a ?ird bat* 0 plac$ 9 #ep]c5t4 solution ( m]curic *loride4 ,simil>ly a bat* ( ?ree horse-*e/nut leaf-/alks 0 put 9 wat]1 ano!r bat* 9 *lor(orm-wat]1 & a ?ird bat* 9 m]curic *loride solution4 ,i4 ,,leaf-,,/alk ,,( ,,plane-,,tree ,! /imulus appli$ 0 a s+le vibration ( #ij4 ,a4 ,aft] #bd;h\rs 9 ,b4 ,aft] #bd;h\rs 9 ,c4 ,aft] #bd;h\rs 9 wat] *lor(orm wat] m]curic *loride ,all leaves /&+ up ,leaves began to ,leaves began to droop & fre%--aphides droop 9 #a;h\r 9 #d;h\rs4 ,deep alive & b5t ov] 9 discol\ration along #c;h\rs--aphides ! ve9s4 ,aphides dead dead ,electric ,electric ,electric ,response response response 7#a7 #ba dns4 7#a7 #a dn4 7#a7 #j dn4 7#b7 #ca 7#b7 #a 7#b7 #be 7#c7 #bf 7#c7 #b 7#c7 #be 7#d7 #ae 7#d7 #j 7#d7 #j 7#e7 #ag 7#e7 #a 7#e7 #be 7#f7 #bc 7#f7 #ae 7#f7 #be 7#g7 #cj 7#g7 #b 7#g7 #j 7#h7 #bg 7#h7 #a 7#h7 #be 7#i7 #bi 7#i7 #a 7#i7 #be 7#aj7 #ag 7#aj7 #e 7#aj7 #e ---------------------------------------- ----------------------------- ,mean response #bcf ,mean #a ,mean #ae ,,ii4 ,,leaf-,,/alk ,,( ,,horse-,,*e/nut 7#a7 #ae dns4 7#a7 #e dn4 7#a7 #j dn4 7#b7 #ag 7#b7 #e 7#b7 #j 7#c7 #aj 7#c7 #j 7#c7 #j ---------------------------------------- ----------------------------- ,mean #ad ,mean #c ,mean #j ,^! results conclusively prove ! physiological nature ( ! response4 ,i %all 9 a succe$+ *apt] give a cont9u\s s]ies ( response-curves %[+ h[1 ow+ to progressive dea? f ! action ( poison1 ! responses und]go /eady dim9ution till !y are completely aboli%$4 ,effect ( high temp]ature4--,x is well kn[n t plants are kill$ :5 subject$ to high temp]atures4 ,i took a /alk1 &1 us+ ! block me?od1 ) torsional vibration z ! /imulus1 obta9$ /rong responses at bo? ends ,a & ,b4 ,i !n imm]s$ ! same /alk = a %ort "t 9 hot wat] at ab\t #fe;,c41 & aga9 /imulat$ x z be=e4 ,b at nei!r ,a nor ,b c\ld any response n[ be evok$4 ,z all ! ext]nal conditions 7 ! same 9 ! fir/ & second p>ts ( ?is exp]im5t1 ! only diff]5ce be+ t 9 "o ! /alk 0 alive & 9 ! o!r kill$1 we h "h fur!r & conclusive pro( ( ! physiological "* ( electric response 9 plants4 ,! same facts may be demon/rat$ 9 a /ill m /rik+ mann] by fir/ obta9+ two simil> b opposite responses 9 a fre% /alk1 at ,a & ,b1 & !n kill+ "o half1 say ,b1 by imm]s+ only t half ( ! /alk 9 hot wat]4 ,! /alk is replac$ 9 ! app>atus1 & x is n[ f\nd t :]eas ! ,a half gives /rong response1 ! end ,b gives none4 ,9 ! exp]im5ts on negative v>iation1 x 0 tacitly assum$ t ! v>iation is due to a diff]5tial action1 /imulus produc+ a great] excitation at ! un9jur$ ?an at ! injur$ end4 ,! block me?od enables u to te/ ! correctness ( ?is assumption4 ,! ,b end ( ! /alk is injur$ or kill$ by a few drops ( /rong pota%1 ! o!r end be+ un9jur$4 ,!re is a clamp betwe5 ,a & ,b4 ,! end ,a is /imulat$ & a /rong response is obta9$4 ,! end ,b is n[ /imulat$1 & !re is little or no response4 ,! block is n[ remov$ & ! plant /imulat$ ?r\gh\t its l5g?4 ,?\gh ! /imulus n[ acts on bo? ends1 yet1 ow+ to ! irresponsive condition ( ,b1 !re is a resultant response1 :i* f its direction is f\nd to be due to ! responsive action ( ,a4 ,?is w\ld n h be5 ! case if ! end ,b _h be5 un9jur$4 ,we h ?us exp]im5tally v]ifi$ ! assumption t 9 ! same tissue an un9jur$ portion w be ?r[n into a great] excitatory /ate ?an an injur$1 by ! action ( ! same /imulus4 ,,*apt] ,v ,,plant ,,response--,,on ,,! ,,effects ,,( ,,s+le ,,/imulus ,,& ,,( ,,sup]pos$ ,,/imuli ,effect ( s+le /imulus--,sup]position ( /imuli--,additive effect--,/aircase effect--,fatigue--,no fatigue :5 suffici5t int]val betwe5 /imuli--,app>5t fatigue :5 /imulation frequ5cy is increas$--,fatigue "u cont9u\s /imulation4 ,effect ( s+le /imulus4--,9 a muscle a s+le /imulus gives rise to a s+le twit* :i* may be record$ ei!r me*anically or electrically4 ,if !re is no fatigue1 ! successive responses to uni=m /imuli are exactly simil>4 ,muscle :5 /rongly /imulat$ (t5 exhibits fatigue1 & successive responses !re=e become feebl] & feebl]4 ,9 n]ves1 h[ev]1 !re is practically no fatigue & successive records are alike4 ,simil>ly1 9 plants1 we %all f9d "s exhibit+ m>k$ fatigue & o!rs v little4 ,sup]position ( /imuli4--,if in/ead ( a s+le /imulus a succession ( /imuli be sup]pos$1 x happ5s t a second %ock is receiv$ be=e recov]y f ! fir/ has tak5 place4 ,individual effects w !n become m or less fus$4 ,:5 ! frequ5cy is suffici5tly increas$1 ! int]mitt5t effects are fus$1 & we f9d an almo/ unbrok5 curve4 ,:5 = example ! muscle atta9s its maximum contraction 7correspond+ to ! frequ5cy & /r5g? ( /imuli7 x is ?r[n into a /ate ( complete tetanus1 9 :i* x appe>s to be held rigid4 ,if ! rapidity be n suffici5t = ?is1 we h ! jagg$ curve ( incomplete tetanus4 ,if !re is n mu* fatigue1 ! upp] "p ( ! tetanic curve is approximately horizontal1 b 9 cases :]e fatigue sets 9 quickly1 ! fact is %[n by ! rapid decl9e ( ! curve4 ,) reg>d to all ^! po9ts we f9d /rict p>allels 9 plant response4 ,9 cases :]e !re is no fatigue1 ! successive responses are id5tical 7fig4#af74 ,) sup]position ( /imuli we h fusion ( effects1 analog\s to ! tetanus ( muscle 7fig4#ag74 ,& la/ly1 ! influ5ce ( fatigue 9 plants is to produce a modification ( response-curve exactly simil> to t ( muscle 7see bel[74 ,"o effect ( sup]position ( /imuli may be m5tion$ "h4 ,illu/ration3 ,,fig4#af4--,,uni=m ,,responses 7,,radi%7 ,illu/ration3 ,,fig4#ag4--;,,fusion ,,( ,,effect ,,( ,,rapidly ,,succe$+ ,,/imuli 7a7 9 muscle2 7b7 9 c>rot4 ,additive effect4--,x is f\nd 9 animal responses t !re is a m9imum int5sity ( /imulus1 bel[ :i* no response c be evok$4 ,b ev5 a sub-m9imal /imulus w1 ?\gh s+ly ineffective1 become effective by ! summation ( sev]al4 ,9 plants1 too1 we obta9 a simil> effect1 i4e4 ! summation ( s+le ineffective /imuli produces effective response 7fig4#ah74 ,illu/ration3 ,,fig4#ah4--;,,additive ,,effect 7a7 ,a s+le /imulus ( #c vibration produc$ little or no effect1 b ! same /imulus :5 rapidly sup]pos$ ?irty times1 produc$ ! l>ge effect 7b74 7,leaf-/alk ( turnip47 ,/aircase effect4--,animal tissues sometimes exhibit :at is kn[n z ! '/aircase effect1' t is to say1 ! heights ( successive responses are gradually increas$1 ?\gh ! /imuli are ma9ta9$ con/ant4 ,?is is exhibit$ typically by c>diac muscle1 ?\gh x is n unkn[n ev5 9 n]ve4 ,! cause is obscure1 b x seems to dep5d on ! condition ( ! tissue4 ,x appe>s z if ! molecul> sluggi%ness ( tissue 7 9 ^! cases only gradually remov$ "u /imulation1 & ! increas$ effects 7 due to increas$ molecul> mobility4 ,:atev] be ! explanation1 ,i h sometimes obs]v$ ! same /aircase effect 9 plants 7fig4#ai74 ,illu/ration3 ,,fig4#ai4--',,/aircase ,,effect' ,,9 ,,plant ,fatigue4--,x is assum$ t 9 liv+ sub/ances l muscle1 fatigue is caus$ by ! break d[n or dissimilation ( tissue by /imulus4 ,& till ?is wa/e is repair$ by ! process ( build+-up or assimilation1 ! functional activity ( ! tissue w rema9 bel[ p>4 ,!re may also be an accumulation ( ! products ( dissimilation--'! fatigue /uffs'--& ^! latt] may act z poisons or *emical depressants4 ,9 an animal x is suppos$ t ! nutritive blood supply p]=ms ! two-fold task ( br++ mat]ial = assimilation & remov+ ! fatigue products1 ?us caus+ ! disappe>ance ( fatigue4 ,?is explanation1 h[ev]1 is %[n to be insuffici5t by ! fact t an excis$ bloodless muscle recov]s f fatigue aft] a %ort p]iod ( re/4 ,x is obvi\s t "h ! fatigue has be5 remov$ by means o!r ?an t ( r5ew$ assimilation & removal ( fatigue products by ! circulat+ blood4 ,x may !re=e be in/ructive to /udy c]ta9 phases ( fatigue exhibit$ "u simpl] conditions 9 vegetable tissue1 :]e ! con/ructive processes are 9 abeyance1 & !re is no active circulation = ! removal ( fatigue products4 ,x has be5 said be=e t ! ,e4,m4 v>iation caus$ by /imulus is ! concomitant ( a di/urbance ( ! molecules ( ! responsive tissues f _! normal equilibrium1 & t ! curve ( recov]y exhibits ! re/oration ( ! tissue to equilibrium4 ,no fatigue :5 suffici5t int]val betwe5 successive /imuli4--,we may ?us ga!r f a /udy ( ! response-curve "s indication ( ! molecul> di/ortion exp]i5c$ by ! excit$ tissue4 ,let u fir/ take ! case ( an exp]im5t ^: record is giv5 9 fig4#bj1 a4 ,x w be se5 f t curve t "o m9ute aft] ! application ( /imulus !re is a complete recov]y ( ! tissue2 ! molecul> condition is exactly ! same at ! end ( recov]y z 9 ! beg9n+ ( /imulation4 ,! second & succe$+ response-curves !re=e are exactly simil> to ! fir/1 provid$ a suffici5t int]val has be5 all[$ 9 ea* case = complete recov]y4 ,!re is1 9 su* a case1 no dim9ution 9 int5sity ( response1 t is to say1 no fatigue4 ,we h an exactly p>allel case 9 muscles4 ',9 muscle ) normal circulation & nutrition !re is always an int]val betwe5 ea* pair ( /imuli1 9 :i* ! height ( twit* does n dim9i% ev5 aft] protract$ excitation1 & no fatigue appe>s4'#aj ,illu/ration3 ,,fig4#bj4--,,record ,,%[+ ,,dim9ution ,,( ,,response ,,:5 ,,suffici5t ,,"t ,,is ,,n ,,all[$ ,,= ,,full ,,recov]y ,9 7a7 /imuli 7 appli$ at int]vals ( "o m9ute2 9 7b7 ! int]vals 7 r$uc$ to half a m9ute2 ?is caus$ a dim9ution ( response4 ,9 7c7 ! orig9al rhy?m is re/or$1 & ! response is f\nd to be enhanc$4 7,radi%47 ,app>5t fatigue :5 /imulation frequ5cy increas$4--,if ! rhy?m ( /imulation frequ5cy be n[ *ang$1 & made quick]1 c]ta9 rem>kable modifications w appe> 9 ! response-curves4 ,9 fig4#bj1 ! fir/ "p %[s ! responses at "o m9ute int]val1 by :i* "t ! individual recov]y 0 complete4 ,! rhy?m 0 n[ *ang$ to int]vals ( half a m9ute1 in/ead ( "o1 :ile ! /imuli 7 ma9ta9$ at ! same int5sity z be=e4 ,x w be notic$ 7fig4#bj1 b7 t ^! responses appe> mu* feebl] ?an ! fir/ set1 9 spite ( ! equality ( /imulus4 ,an inspection ( ! figure may p]haps ?r[ "s light on ! subject4 ,x w be se5 t :5 great] frequ5cy ( /imulation 0 introduc$1 ! tissue _h n yet _h "t to effect complete recov]y f previ\s /ra94 ,! molecul> sw+ t[>ds equilibrium _h n yet abat$1 :5 ! new /imulus1 ) its oppos+ impulse1 0 receiv$4 ,!re is ?us a dim9ution ( height 9 ! resultant response4 ,! orig9al rhy?m ( "o m9ute 0 n[ re/or$1 & ! succe$+ curves 7fig4#bj1 c7 at once %[ increas$ response4 ,an analog\s in/ance may be cit$ 9 ! case ( muscle response1 :]e '! height ( twit* dim9i%es m rapidly 9 proportion z ! excitation int]val is %ort]4'#aa ,illu/ration3 ,,fig4#ba4--;,,fatigue ,,9 ,,cel]y ,vibration ( #cj at int]vals ( half a m9ute4 ,f :at has j be5 said x w\ld appe> t "o ( ! causes ( dim9ution ( response1 or fatigue1 is ! residual /ra94 ,?is is cle>ly se5 9 fig4#ba1 9 a record :i* ,i obta9$ ) cel]y-/alk4 ,x w be notic$ !re t1 ow+ to ! imp]fect molecul> recov]y dur+ ! "t all[$1 ! succe$+ heights ( ! responses h und]gone a cont9u\s dim9ution4 ,fig4#bb gives a photographic record ( fatigue 9 ! leaf-/alk ( caulifl[]4 ,illu/ration3 ,,fig4#bb4--;,,fatigue ,,9 ,,leaf-,,/alk ,,( ,,caulifl[] ,/imulus3 #cj vibration at int]vals ( "o m9ute4 ,x is evid5t t residual /ra91 o!r ?+s be+ equal1 w be great] if ! /imuli h be5 excessive4 ,?is is well se5 9 fig4#bc1 :]e ! set ( fir/ ?ree curves ,a is = /imulus int5sity ( #de vibration1 & ! second set ,b1 ) an augm5t$ response1 = /imulus int5sity ( #ij vibration4 ,on rev]t+ 9 ,c to /imulus int5sity ( #de1 ! responses are se5 to h und]gone a great dim9ution z comp>$ ) ! fir/ set ,a4 ,"h is se5 m>k$ fatigue1 ! result ( ov]/ra9 f excessive /imulation4 ,illu/ration3 ,,fig4#bc4--;,,effect ,,( ,,ov]/ra9 ,,9 ,,produc+ ,,fatigue ,successive /imuli appli$ at int]vals ( "o m9ute4 ,! int5sity ( /imulus 9 ,c is ! same z t ( ,a1 b response is feebl] ow+ to previ\s ov]-/imulation4 ,fatigue is to a great ext5t remov$ aft] fifte5 m9utes' re/1 & ! responses 9 ,d are /rong] ?an ^? 9 ,c4 ,! v]tical l9e betwe5 arr[s repres5ts #jevolt4 7,turnip leaf-/alk47 ,if ?is fatigue be really due to residual /ra9 effect1 !n1 z /ra9 disappe>s ) "t1 we may expect ! responses to rega9 _! =m] height aft] a p]iod ( re/4 ,9 ord] to v]ify ?is1 !re=e1 ,i r5ew$ ! /imulation 7at int5sity #de7 aft] fifte5 m9utes4 ,x w at once be se5 f record ,d h[ f> ! fatigue _h be5 remov$4 ,"o peculi>ity t w be notic$ 9 ^! curves is t1 ow+ to ! pres5ce ( comp>atively little residual /ra91 ! fir/ response ( ea* set is relatively l>ge4 ,! succe$+ responses are approximately equal :]e ! residual /ra9s are simil>4 ,! fir/ response ( ,a %[s ?is because x _h _h long previ\s re/4 ,! fir/ ( ,b %[s x because we are !re pass+ = ! fir/ "t to increas$ /imulation4 ,! fir/ ( ,c does n %[ x1 because !re is n[ a /rong residual /ra94 ,d aga9 %[s x because ! /ra9 has be5 remov$ by fifte5 m9utes' re/4 ,fatigue "u cont9u\s /imulation4--,! effect ( fatigue is exhibit$ 9 m>k$ degree :5 a tissue is subject$ to cont9u\s /imulation4 ,9 cases :]e !re is m>k$ fatigue1 z = in/ance 9 c]ta9 muscles1 ! top ( ! tetanic curve und]goes rapid decl9e4 ,a simil> effect is obta9$ also ) plants 7fig4#bd74 ,illu/ration3 ,,fig4#bd4--,,rapid ,,fatigue ,,"u ,,cont9u\s ,,/imulation ,,9 7a7 ,,muscle2 7b7 ,,9 ,,leaf-,,/alk ,,( ,,cel]y ,! effect ( re/ 9 produc+ molecul> recov]y1 & h5ce 9 ! removal ( fatigue1 is well illu/rat$ 9 ! foll[+ set ( photographic records 7fig4#be74 ,! fir/ %[s ! curve obta9$ ) a fre% plant4 ,! effect is se5 to be v l>ge4 ,two m9utes 7 all[$ = recov]y1 & !n /imulation 0 repeat$ dur+ ano!r two m9utes4 ,! response 9 ?is case is se5 to be decid$ly small]4 ,a ?ird case is some:at simil> to ! second4 ,a p]iod ( re/ ( five m9utes 0 n[ all[$1 & ! curve obta9$ subsequ5tly1 ow+ to p>tial removal ( residual /ra91 is f\nd to exhibit great] response4 ,illu/ration3 ,,fig4#be4--;,,effect ,,( ,,cont9u\s ,,vibration 7,,?r\gh #ej7 ,,9 ,,c>rot ,9 ! fir/ ?ree records1 two m9utes' /imulation is foll[$ by two m9utes' recov]y4 ,! la/ record 0 tak5 aft] ! specim5 _h a re/ ( five m9utes4 ,! response1 ow+ to removal ( fatigue by re/1 is /rong]4 ,! results ?us arriv$ at1 "u ! simple conditions ( vegetable life1 free z !y are f all possible complications & unc]ta9ties1 may p]haps ?r[ "s light on ! obscure ph5om5a ( fatigue 9 animal tissues4 ,,footnotes3 #aj ,bi$]mann1 ,electro-physiology1 p4#hf4 #aa ,bi$]mann1 loc4 cit4 ,,*apt] ,,vi ,,plant ,,response--,,on ,,diphasic ,,v>iation ,diphasic v>iation--,positive aft]-effect & positive response--,radial ,e4,m4 v>iation4 ,:5 a plant is /imulat$ at any po9t1 a molecul> di/urbance--! excitatory wave--is propagat$ outw>ds f ! po9t ( its initiation4 ,diphasic v>iation4--,?is wave ( molecul> di/urbance is att5d$ by a wave ( electrical di/urbance4 7,usually speak+1 ! electrical relation betwe5 di/urb$ & less di/urb$ is t ( copp] to z9c47 ,x takes "s "t = a di/urbance to travel f "o po9t to ano!r1 & its int5sity may und]go a dim9ution z x rec$es fur!r f its po9t ( orig94 ,suppose a di/urbance orig9at$ at ,c2 if two po9ts are tak5 ne> ea* o!r1 z ,a & ,b1 ! di/urbance w rea* !m almo/ at ! same "t1 & ) ! same int5sity4 ,! electric di/urbance w be ! same 9 bo?4 ,! effect produc$ at ,a & ,b w balance ea* o!r & !re w be no resultant curr5t4 ,by kill+ or o!rwise r$uc+ ! s5sibility ( ,b z is done 9 ! me?od ( injury1 !re is no response at ,b1 & we obta9 ! unbalanc$ response1 due to di/urbance at ,a2 ! same effect is obta9$ by putt+ a clamp betwe5 ,a & ,b1 s t ! di/urbance may n rea* ,b4 ,b we may get response ev5 )\t injury or block4 ,if we h ! contacts at ,a & ,b1 & if we give a tap ne>] ,a ?an ,b 7fig4#bf1 a71 !n we h 7#a7 ! di/urbance rea*+ ,a e>li] ?an ,b4 7#b7 ,! di/urbance rea*+ ,a is mu* /rong] ?an at ,b4 ,! di/urbance at ,b may be s comp>atively feeble z to be negligible4 ,x w ?us be se5 t we might obta9 responses ev5 )\t injury or block1 9 cases :]e ! di/urbance is enfeebl$ 9 rea*+ a di/ant po9t4 ,9 su* a case on giv+ a tap ne> ,a a responsive curr5t w\ld be produc$ 9 "o direction1 & 9 ! opposite direction :5 ! tap is giv5 ne> ,b 7fig4#bf1 b74 ,!oretically1 !n1 we might f9d a neutral po9t betwe5 ,a & ,b1 s t1 on orig9at+ ! di/urbance !re1 ! waves ( di/urbance w\ld rea* ,a & ,b at ! same in/ant & ) ! same int5sity4 ,if1 fur!r1 ! rate ( recov]y be ! same = bo? po9ts1 !n ! electric di/urbances produc$ at ,a & ,b w cont9ue to balance ea* o!r1 & ! galvanomet] w %[ no curr5t4 ,on tak+ a cyl9drical root ( radi% ,i h sometimes succe$$ 9 f9d+ a neutral po9t1 :i*1 be+ di/urb$1 did n give rise to any resultant curr5t4 ,b di/urb+ a po9t to ! "r or to ! left gave rise to opposite curr5ts4 ,x is1 h[ev]1 difficult to obta9 an absolutely cyl9drical specim51 z x always tap]s 9 "o direction4 ,! conductivity t[>ds ! tip ( ! root is n exactly ! same z t 9 ! asc5d+ direction4 ,x is !re=e difficult to fix an absolutely neutral po9t1 b a po9t may be f\nd :i* approa*es ?is v ne>ly1 & on /imulat+ ! /alk ne> ?is1 a v int]e/+ diphasic v>iation has be5 obs]v$4 ,9 a specim5 ( caulifl[]-/alk1 7#a7 /imulus 0 appli$ v mu* ne>] ,a ?an ,b 7! feeble di/urbance rea*+ ,b 0 negligible74 ,! result+ response 0 upw>d & ! recov]y took place 9 ab\t sixty seconds4 ,illu/ration3 ,,fig4#bf4--;,,diphasic ,,v>iation 7#b7 ,/imulus 0 next appli$ ne> ,b4 ,! result+ response 0 n[ d[nw>d 7fig4#bf1 b74 7#c7 ,! /imulus 0 n[ appli$ ne> ! approximately neutral po9t ,n4 ,9 ?is case1 ow+ to a slight diff]5ce 9 ! rates ( propagation 9 ! two directions1 a v int]e/+ diphasic v>iation 0 produc$ 7fig4#bf1 c74 ,f ! record x w be se5 t ! di/urbance arriv$ e>li] at ,a ?an at ,b4 ,?is produc$ an upw>d response4 ,b dur+ ! subsid5ce ( ! di/urbance at ,a1 ! wave rea*$ ,b4 ,! effect ( ?is 0 to produce a curr5t 9 ! opposite direction4 ,?is app>5tly ha/5$ ! recov]y ( ,a 7f #fjseconds to #abseconds74 ,! excitation ( ,a n[ disappe>$1 & ! second phase ( response1 t due to excitation ( ,b1 0 fully display$4 ,positive aft]-effect4--,if we reg>d ! response due to excitation ( ,a z negative1 ! lat] effect on ,b w\ld appe> z a subsequ5t positive v>iation4 ,9 ! response ( n]ve1 = example1 :]e contacts are made at two surfaces1 injur$ & un9jur$1 !re is sometimes obs]v$1 fir/ a negative v>iation1 & !n a positive aft]-effect4 ,?is may sometimes at lea/ be due to ! proximal un9jur$ contact fir/ giv+ ! usual negative v>iation1 & ! m di/ant contact ( injury giv+ rise1 lat]1 to ! opposite1 t is to say1 app>5tly positive1 response4 ,!re is always a *ance ( an aft]-effect due to ?is cause1 unless 7#a7 ! injur$ end be completely kill$ & r5d]$ q irresponsive1 or 7#b7 !re be an effective block betwe5 ,a & ,b1 s t ! di/urbance due to /imulus c only act on "o1 & n on ! o!r4 ,i h f\nd cases :]e1 ev5 :5 !re 0 a p]fect block1 a positive aft]-effect occurr$4 ,x w\ld ?us appe> t if molecul> di/ortion f /imulus give rise to a negative v>iation1 !n dur+ ! process ( molecul> recov]y !re may be ov]-%oot+ ( ! equilibrium position1 :i* may be exhibit$ z a positive v>iation4 ,positive v>iation4--,! responses giv5 by muscle or n]ve are1 normally speak+1 negative4 ,b t ( ret9a is positive4 ,! sign ( response1 h[ev]1 is apt to be rev]s$ if !re be any molecul> modification ( ! tissue f *anges ( ext]nal circum/ances4 ,?us x is (t5 f\nd t n]ve 9 a /ale condition gives positive1 in/ead ( ! normal negative v>iation1 & /ale ret9a (t5 gives negative1 in/ead ( ! usual positive4 ,illu/ration3 ,,fig4#bg4--;,,abnormal ,,positive ,,responses ,,9 ,,/ale ,,leaf-,,/alk ,,( ,,turnip ,,conv]t$ ,,into ,,normal ,,negative ,,"u ,,/rong ,,/imulation#ab ,! relative int5sities ( /imuli 9 ! two cases are 9 ! ratio ( #a3g4 ,curi\sly en\gh1 ,i h on _m occasions f\nd exactly p>allel in/ances 9 ! response ( plants4 ,plants :5 fre%1 z /at$1 give negative responses z a rule4 ,b :5 some:at fad$ !y sometimes give rise to positive response4 ,aga91 j z 9 ! modifi$ n]ve ! abnormal positive response gives place to ! normal negative "u /rong & long-cont9u$ /imulation1 s also 9 ! modifi$ plant ! abnormal positive response passes into negative 7fig4#bg7 "u /rong /imulation4 ,i 0 able 9 "s cases to trace ?is process ( gradual rev]sal1 by cont9u\sly increas+ ! int5sity ( /imulus4 ,x 0 !n f\nd t z ! /imulus 0 increas$1 ! positive at a c]ta9 po9t und]w5t a rev]sal into ! normal negative response 7fig4#bh74 ,illu/ration3 ,,fig4#bh4 ,,abnormal ,,positive ,,pass+ ,,into ,,normal ,,negative ,,9 ,a ,,/ale ,,specim5 ,,( ,,leaf-,,/alk ,,( ,,caulifl[] ,/imulus 0 gradually increas$ f #a to #aj1 by means ( spr+-tapp]4 ,:5 ! /imulus int5sity 0 #aj1 ! response became rev]s$ into normal negative4 7,p>ts ( #h & #i are out ( ! plate47 ,! plant ?us gives a rev]s$ response "u abnormal conditions ( /al5ess4 ,i h sometimes f\nd simil> rev]sal ( response :5 ! plant is subject$ to ! abnormal conditions ( excessively high or l[ temp]ature4 ,radial ,e4,m4 v>iation4--,we h se5 t a curr5t ( response fl[s 9 ! plant f ! relatively m to ! relatively less excit$4 ,a !oretically important exp]im5t is ! foll[+3 ,a ?ick /em ( plant /alk 0 tak5 & a hole bor$ s z to make "o contact ) ! int]ior ( ! tissue1 ! o!r be+ on ! surface4 ,aft] a :ile ! curr5t ( injury 0 f\nd to disappe>4 ,on excit+ ! /em by taps or torsional vibration1 a responsive curr5t 0 obs]v$ :i* fl[$ inw>ds f ! m di/urb$ out] surface to ! %ield$ core inside 7fig4#bi74 ,h5ce x is se5 t :5 a wave ( di/urbance is propagat$ along ! plant1 !re is a concomitant wave ( radial ,e4,m4 v>iation4 ,! sway+ ( a tree by ! w9d w\ld ?us appe> to give rise to a radial ,e4,m4,f4 ,illu/ration3 ,,fig4#bi4--,,radial ,e4,m4 ,,v>iation ,,footnotes3 #ab ,= g5]al purposes x is immat]ial :e!r ! responses are record$ up or d[n4 ,= conv5i5ce ( inspection !y are 9 g5]al record$ up4 ,b 9 cases :]e x is necess>y to discrim9ate ! sign ( response1 positive response w be record$ up1 & negative d[n4 ,,*apt] ,,vii ,,plant ,,response--,,on ,,! ,,relation ,,betwe5 ,,/imulus ,,& ,,response ,increas$ response ) increas+ /imulus--,app>5t dim9ution ( response ) excessively /rong /imulus4 ,z already said1 9 ! liv+ tissue1 molecul> di/urbance induc$ by /imulus is accompani$ by an electric di/urbance1 :i* gradually disappe>s ) ! return ( ! di/urb$ molecules to _! position ( equilibrium4 ,! great] ! molecul> di/ortion produc$ by ! /imulus1 ! great] is ! electric v>iation produc$4 ,! electric response is ?us an outw>d expression ( a molecul> di/urbance produc$ by an ext]nal ag5cy1 ! /imulus4 ,curve ( relation betwe5 /imulus & response4--,9 ! curve %[+ ! relation betwe5 /imulus & response 9 n]ve & muscle1 x is f\nd t ! molecul> effect z exhibit$ ei!r by contraction or ,e4,m4 v>iation 9 muscle1 or simply by ,e4,m4 v>iation 9 n]ve1 is at fir/ slight4 ,9 ! second "p1 !re is a rapidly increas+ effect ) increas$ /imulus4 ,f9ally1 a t5d5cy %[s itself to approa* a limit ( response4 ,?us we f9d ! curve at fir/ slightly convex1 !n /raight & asc5d+1 & la/ly1 concave to ! abscissa 7fig4#cj74 ,9 muscle ! limit ( response is rea*$ mu* soon] ?an 9 n]ve4 ,z w be se51 ! range ( v>iation ( /imulus 9 ^! curves is n v great4 ,:5 ! /imulus is c>ri$ beyond mod]ate limits1 ! response1 ow+ to fatigue or o!r causes1 may sometimes und]go an actual dim9ution4 ,illu/ration3 ,,fig4#cj4--;,,curves ,,%[+ ,,! ,,relation ,,betwe5 ,,! ,,int5sity ,,( ,,/imulus ,,& ,,response ,absciss indicate increas+ int5sity ( /imulus4 ,ord9ates indicate magnitude ( response4 7,wall]47 ,i h obta9$ v int]e/+ results1 ) ref]5ce to ! relation betwe5 /imulus & response1 :5 exp]im5t+ ) plants4 ,^! results are sugge/ive ( v>i\s types ( response met ) 9 animal tissues4 #a4 ,9 ord] to obta9 ! simple/ type ( effects1 n complicat$ by second>y ph5om5a1 "o has to *oose specim5s :i* exhibit little fatigue4 ,hav+ procur$ ^!1 ,i und]took two s]ies ( exp]im5ts4 ,9 ! fir/ 7,a7 ! /imulus 0 appli$ by means ( ! spr+-tapp]1 & 9 ! second 7,b7 by torsional vibration4 ,illu/ration3 ,,fig4#ca ,taps ( increas+ /r5g? #a3b3c3d produc+ increas$ response 9 leaf /alk ( turnip4 7,a7 ,! fir/ /imulus 0 giv5 by a fall ( ! lev] ?r\gh h1 ! second ?r\gh #b;h1 & s on4 ,! response-curves cle>ly %[ increas+ effect ) increas$ /imulus 7fig4#ca74 ,illu/ration3 ,,fig4#cb4--;,,increas$ ,,response ,,) ,,increas+ ,,vibrational ,,/imuli 7,,caulifl[]-,,/alk7 ,/imuli appli$ at int]vals ( ?ree m9utes4 ,v]tical l9e #avolt4 7,b7 #a4 ,! vibrational /imulus 0 increas$ f #be to #e to #ge to #aj to #abe 9 amplitude4 ,x w be obs]v$ h[ ! int5sity ( response t5ds to approa* a limit 7fig4#cb74 ,,table ,,%[+ ,,! ,,increas$ ,e4,m4 ,,v>iation ,,produc$ ,,by ,,increas+ ,,/imulus ---------------------------------------- ,angle ( ,vibration ,e4,m4,f ---------------------------------------- #be #jdd volt #e #jge volt #ge #jij volt #aj #ajj volt #abe #ajf volt --------------------------------------- #b4 ,! next figure %[s h[ little v>iation is produc$ ) l[ value ( /imulus1 b ) increas+ /imulus ! response und]goes a rapid increase1 aft] :i* x t5ds to approa* a limit 7fig4#cc1 a74 ,illu/ration3 ,,fig4#cc4--,,responses ,,to ,,increas+ ,,/imuli ,,produc$ ,,by ,,increas+ ,,angle ,,( ,,vibration 7a7 ,record ) a specim5 ( fre% radi%4 ,/imuli appli$ at int]vals ( two m9utes4 ,! record is tak5 = "o m9ute4 7b7 ,record = /ale radi%4 ,!re is a rev]s$ response = ! feeble /imulus ( #e vibration4 #c4 ,z an extreme in/ance ( ! case j cit$1 ,i h (t5 come across a curi\s ph5om5on4 ,dur+ ! gradual increase ( ! /imulus f a l[ value !re w\ld be app>5tly no response4 ,b :5 a critical value 0 rea*$ a maximum response w\ld sudd5ly occur1 & w\ld n be exce$$ :5 ! /imulus 0 fur!r increas$4 ,"h we h a p>allel to :at is kn[n 9 animal physiology z ! 'all or none' pr9ciple4 ,) ! c>diac muscle1 = example1 !re is a c]ta9 m9imal int5sity :i* is effective 9 produc+ response1 b fur!r increase ( /imulus produces no increase 9 response4 #d4 ,f an inspection ( ! records ( responses :i* are giv51 x w be se5 t ! slope ( a curve :i* %[s ! relation ( /imulus to response w at fir/ be slight1 ! curve w !n asc5d rapidly1 & at high values ( /imulus t5d to become horizontal4 ,! curve z a :ole becomes1 fir/ slightly convex to ! abscissa1 !n /raight & asc5d+1 & la/ly concave4 ,a f> m pron\nc$ convexity 9 ! fir/ "p is %[n 9 "s cases1 especially :5 ! specim5 is /ale4 ,?is is due to ! fact t "u ^! circum/ances response is apt to beg9 ) an actual rev]sal ( sign1 ! plant "u feebl] ?an a c]ta9 critical int5sity ( /imulus giv+ positive1 in/ead ( ! normal negative1 response 7fig4#cc1 b74 ,dim9ution ( response ) excessively /rong /imulus4--,x is f\nd t 9 animal tissues !re is sometimes an actual dim9ution ( response ) excessive increase ( /imulus4 ,?us ,wall] f9ds1 9 work+ ) ret9a1 t z ! int5sity ( light /imulus is gradually increas$1 ! response at fir/ increases1 & !n sometimes und]goes a dim9ution4 ,?is ph5om5on is un=tunately complicat$ by fatigue1 itself reg>d$ z obscure4 ,x is !re=e difficult to say :e!r ! dim9ution ( response is due to fatigue or to "s rev]s+ action ( an excessively /rong /imulus4 ,f fig4#cc1 b1 above1 x is se5 t !re 0 an actual rev]sal ( response 9 ! l[] portion ( ! curve4 ,x is !re=e n improbable t !re may be m ?an "o po9t ( rev]sal4 ,9 physical ph5om5a we are1 h[ev]1 acqua9t$ ) num]\s in/ances ( rev]sals4 ,= example1 a common effect ( magnetisation is to produce an elongation ( an iron rod4 ,b ,bidwell f9ds t z ! magnetis+ =ce is pu%$ to an extreme1 at a c]ta9 po9t elongation ceases & is succe$$1 ) fur!r increase ( magnetis+ =ce1 by an actual contraction4 ,aga9 a photographic plate1 :5 expos$ cont9u\sly to light1 gives at fir/ a negative image4 ,/ill long] exposure produces a positive4 ,!n aga9 we h a negative4 ,!re is ?us produc$ a s]ies ( recurr5t rev]sals4 ,9 photographic pr9ts ( fla%es ( lightn+1 two k9ds ( images are obs]v$1 "o1 ! positive--:5 ! lightn+ dis*>ge is mod]ately int5se--& ! o!r1 negative1 ! s-call$ 'd>k lightn+'--due to ! rev]sal action ( an int5sely /rong dis*>ge4 ,9 /udy+ ! *anges ( conductivity produc$ 9 metallic p>ticles by ! /imulus ( ,h]tzian radiation1 ,i h (t5 notic$ t :]eas feeble radiation produces "o effect1 /rong radiation produces ! opposite4 ,aga91 "u ! cont9u\s action ( electric radiation1 ,i h frequ5tly f\nd recurr5t rev]sals4#ac ,dim9ution ( response "u /rong /imulus trac$ to fatigue4--,b !re are in/ances 9 plant response :]e ! dim9ution effect c be def9itely trac$ to fatigue4 ,! records ( ^! cases are extremely sugge/ive z to ! mann] 9 :i* ! dim9ution is br\ght ab\t4 ,! accompany+ figures 7fig4#cd7 give records ( responses to increas+ /imulus4 ,!y 7 made ) specim5s ( caulifl[]-/alks1 "o ( :i* 7a7 %[$ little fatigue1 :ile 9 ! o!r 7b7 fatigue 0 pres5t4 ,x w be se5 t ! curves obta9$ by jo9+ ! apices ( ! successive s+le responses are v simil>4 ,illu/ration3 ,,fig4#cd4--,,responses ,,to ,,increas+ ,,/imulus ,,obta9$ ,,) ,,two ,,specim5s ,,( ,,/alk ,,( ,,caulifl[] ,9 7a7 fatigue is abs5t1 9 7b7 x is pres5t4 ,9 "o case !re is no fatigue1 ! recov]y f ea* /imulus be+ complete4 ,e response 9 ! s]ies !re=e />ts f a position ( p]fect equilibrium1 & ! height ( ! s+le responses increases ) increas+ /imulation4 ,b 9 ! second case1 ! /ra9 is n completely remov$ aft] any s+le /imulation ( ! s]ies4 ,t recov]y is p>tial is se5 by ! gradual %ift+ ( ! base l9e upw>ds4 ,9 ! =m] case ! base l9e is horizontal & repres5ts a condition ( complete equilibrium4 ,n[1 h[ev]1 ! base l9e1 or l9e ( modifi$ equilibrium1 is tilt$ upw>ds4 ,?us ev5 9 ?is case if we measure ! heights ( successive responses f ! l9e ( absolute equilibrium1 !y w be f\nd to increase ) increas+ /imulus4 ,ord9>ily1 h[ev]1 we make no all[ance = ! %ift+ ( ! base l9e1 measur+ response r f ! place ( its previ\s recov]y1 or f ! po9t ( modifi$ equilibrium4 ,judg$ 9 ?is way1 ! responses und]go an app>5t dim9ution4 ,,footnotes3 #ac ,see ',on ,electric ,t\*1' ,proc4 ,roy4 ,soc4 ,aug4#aijj4 ,,*apt] ,,viii ,,plant ,,response--,,on ,,! ,,influ5ce ,,( ,,temp]ature ,effect ( v l[ temp]ature--,influ5ce ( high temp]ature--,det]m9ation ( dea?-po9t--,increas$ response z aft]-effect ( temp]ature v>iation--,dea? ( plant & abolition ( response by ! action ( /eam4 ,= e plant !re is a range ( temp]ature mo/ fav\rable to its vital activity4 ,above ?is optimum1 ! vital activity dim9i%es1 till a maximum is rea*$1 :5 x ceases altoge!r1 & if ?is po9t be ma9ta9$ = a long "t ! plant is apt to be kill$4 ,simil>ly1 ! vital activity is dim9i%$ if ! temp]ature be l[]$ bel[ ! optimum1 & aga91 at a m9imum po9t x ceases1 :ile bel[ ?is m9imum ! plant may be kill$4 ,we may reg>d ^! maximum & m9imum temp]atures z ! dea?-po9ts4 ,"s plants c resi/ ^! extremes bett] ?an o!rs4 ,l5g? ( exposure1 x %\ld h[ev] be rememb]$1 is also a det]m9+ factor 9 ! "q z to :e!r or n ! plant %all survive unfav\rable conditions ( temp]ature4 ,?us we h h>dy plants1 & plants t are affect$ by excessive v>iations ( temp]ature4 ,)9 ! *>act]i/ic p[] ( ! species1 !re may be1 aga91 a c]ta9 am\nt ( individual diff]5ce4 ,^! facts be+ kn[n1 ,i 0 anxi\s to det]m9e :e!r ! und\bt$ *anges induc$ by temp]ature 9 ! vital activity ( plants w\ld affect electrical response4 ,effect ( v l[ temp]ature4--,z reg>ds ! influ5ce ( v l[ temp]ature1 ,i _h opportunities ( /udy+ ! "q on ! sudd5 appe>ance ( fro/4 ,9 ! previ\s week1 :5 ! temp]ature 0 ab\t #aj;,c41 ,i _h obta9$ /rong electric response 9 radi%es ^: value v>i$ f #je to #avolt4 ,b two or ?ree days lat]1 z ! effect ( ! fro/1 ,i f\nd electric response to h practically disappe>$4 ,a few radi%es 71 h[ev]1 f\nd some:at resi/ant1 b ! electric response _h1 ev5 9 ^! cases1 fall5 f ! av]age value ( #jge,v4 "u normal temp]ature to #jjc,v4 aft] ! fro/4 ,t is to say1 ! av]age s5sitiv5ess _h be5 r$uc$ to ab\t #a_/be?4 ,on w>m+ ! fro/-bitt5 radi% to #bj;,c4 !re 0 an appreciable revival1 z %[n by increase 9 response4 ,9 specim5s :]e ! effect ( fro/ _h be5 v great1 i4e4 9 ^? :i* %[$ little or no electric response1 w>m+ did n re/ore responsiv5ess4 ,f ?is x w\ld appe> t fro/ kill$ "s1 :i* c\ld n be subsequ5tly reviv$1 :]eas o!rs 7 only r$uc$ to a condition ( torpidity1 f :i* !re 0 revival on w>m+4 ,i n[ tri$ ! effect ( artificial l[]+ ( temp]ature on v>i\s plants4 ,a plant :i* is v easily affect$ by cold is a c]ta9 species ( ,eu*>is lily4 ,i fir/ obta9$ responses ) ! leaf-/alk ( ?is lily at ! ord9>y temp]ature ( ! room 7#ag;,c474 ,i !n plac$ x = fifte5 m9utes 9 a cool+ *amb]1 temp]ature -#b;,c41 = only t5 m9utes1 aft] :i*1 on try+ to obta9 response1 x 0 f\nd to h practically disappe>$4 ,i n[ w>m$ ! plant by imm]s+ x = a:ile 9 wat] at #bj;,c41 & ?is produc$ a revival ( ! response 7fig4#ce74 ,if ! plant be subject$ to l[ temp]ature = too long a "t1 !re is !n no subsequ5t revival4 ,illu/ration3 ,,fig4#ce4--;,,dim9ution ,,( ,,response ,,9 ,,eu*>is ,,by ,,l[]+ ,,( ,,temp]ature 7a7 ,normal response at #ag;,c4 7b7 ,! response almo/ disappe>s :5 plant is subject$ to -#b;,c4 = fifte5 m9utes4 7c7 ,revival ( response on w>m+ to #bj;,c4 ,i obta9$ a simil> m>k$ dim9ution ( response ) ! fl[]-/alk ( ,arum lily1 on l[]+ ! temp]ature to z]o4 ,my next attempt 0 to comp>e ! s5sibility ( diff]5t plants to ! effect ( l[]$ temp]atures4 ,= ?is purpose ,i *ose ?ree specim5s3 7#a7 ,eu*>is lily2 7#b7 ,ivy2 & 7#c7 ,holly4 ,i took _! normal response at #ag;,c41 & f\nd t1 g5]ally speak+1 !y atta9$ a fairly con/ant value aft] ! ?ird or f\r? response4 ,aft] tak+ ^! records ( normal response1 ,i plac$ ! specim5s 9 an ice-*amb]1 temp]ature #j;,c41 = tw5ty-f\r h\rs1 & aft]w>ds took _! records once m at ! ord9>y temp]ature ( ! room4 ,f ^! x w be se5 t :ile ! responsiv5ess ( ,eu*>is lily1 kn[n to be susceptible to ! effect ( cold1 _h entirely disappe>$1 t ( ! h>di] plants1 ,holly & ,ivy1 %[$ v little *ange 7fig4#cf74 ,ano!r v curi\s effect t ,i h notic$ is t :5 a plant approa*es its dea?-po9t by reason ( excessively high or l[ temp]ature1 n only is its g5]al responsiv5ess dim9i%$ almo/ to z]o1 b ev5 ! slight response occasionally becomes rev]s$4 ,illu/ration3 ,,fig4#cf4--;,,aft]-,,effect ,,( ,,cold ,,on ,,ivy1 ,,holly1 ,,& ,,eu*>is ,,lily a4 ,! normal response2 b4 ,response aft] subjection to freez+ temp]ature = tw5ty-f\r h\rs4 ,influ5ce ( high temp]ature1 & det]m9ation ( dea?-po9t4--,i next tri$ to f9d out :e!r a rise ( temp]ature produc$ a depression ( response1 & :e!r ! response disappe>$ at a maximum temp]ature--! temp]ature ( dea?-po9t4 ,= ?is purpose ,i took a bat* ( six radi%es & obta9$ f !m responses at gradually increas+ temp]atures4 ,^! specim5s 7 obta9$ late 9 ! season1 & _! electric responsiv5ess 0 mu* l[] ?an ^? obta9$ e>li]4 ,! plant1 previ\sly kept = five m9utes 9 wat] at a def9ite temp]ature 7say #ag;,c471 0 m\nt$ 9 ! vibration app>atus & responses obs]v$4 ,! plant 0 !n dism\nt$1 & replac$ 9 ! wat]-ba? at a high] temp]ature 7say #cj;,c47 aga91 = five m9utes4 ,a second set ( responses 0 n[ tak54 ,9 ?is way obs]vations 7 made ) ea* specim5 till ! temp]ature at :i* response almo/ or altoge!r ceas$ 0 rea*$4 ,i give bel[ a table ( results obta9$ ) six specim5s ( radi%1 f :i* x w\ld appe> t response beg9s to be aboli%$ 9 ^! cases at temp]atures v>y+ f #ec to #ee;,c4 ,,table ,,%[+ ,,effect ,,( ,,high ,,temp]ature ,,9 ,,aboli%+ ,,response ,temp]ature ,galvanometric response 7#ajj;dns4 #jg,v47 7#a7 #ag;,c #gj dns4 #ec #d 7#b7 #ag #afj #ec #a 7#c7 #ag #ajj #ej #b 7#d7 #ag #hj #ee #j 7#e7 #ag #dj #fj #j 7#f7 #ag #fj #ee #j ,illu/ration3 ,,fig4#cg4--,,! ,,glass ,,*amb] ,,conta9+ ,,! ,,plant ,amplitude ( vibration :i* det]m9es ! int5sity ( /imulus is measur$ by ! graduat$ circle se5 to ! "r4 ,temp]ature is regulat$ by ! electric heat+ coil ,r4 ,= exp]im5ts on action ( an/hetics1 vap\r ( *lor(orm is bl[n 9 ?r\gh ! side tube4 ,electric heat+4--,! exp]im5ts j describ$ 71 h[ev]1 r tr\blesome1 inasmu* z1 9 ord] to produce ea* v>iation ( temp]ature1 ! specim5 _h to be tak5 out ( ! app>atus1 w>m$1 & rem\nt$4 ,i !re=e introduc$ a modification by :i* ?is difficulty 0 obviat$4 ,! specim5 0 n[ enclos$ 9 a glass *amb] 7fig4#cg71 :i* also conta9$ a spiral ( ,g]man-silv] wire1 ?r\gh :i* electric curr5ts c\ld be s5t1 = ! purpose ( heat+ ! *amb]4 ,by v>y+ ! int5sity ( ! curr5t1 ! temp]ature c\ld be regulat$ at w4 ,! specim5 *os5 = exp]im5t 0 ! leaf-/alk ( cel]y4 ,x 0 kept at ea* giv5 temp]ature = t5 m9utes1 & two records 7 tak5 dur+ t "t4 ,x 0 !n rais$ by #aj;,c41 & ! same process 0 repeat$4 ,x w be notic$ f ! record 7fig4#ch7 t 9 ?is p>ticul> case1 z ! temp]ature rose f #bj;,c4 to #cj;,c41 !re 0 a m>k$ dim9ution ( response4 ,at ! same "t1 9 ?is case at lea/1 recov]y 0 quick]4 ,at #bj;,c41 = example1 ! response 0 #ba;dns41 & ! recov]y 0 n complete 9 ! c\rse ( a m9ute4 ,at #cj;,c41 h[ev]1 ! response _h be5 r$uc$ to #ge;divisions1 b !re 0 almo/ complete recov]y 9 twelve seconds4 ,z ! temp]ature 0 gradually increas$1 a cont9u\s decrease ( response occurr$4 ,?is dim9ution ( response ) increas$ temp]ature appe>s to be univ]sal1 b ! quick5+ ( recov]y may be true ( individual cases only4 ,illu/ration3 ,,fig4#ch4--;,,effect ,,( ,,temp]ature ,,on ,,response ,! response 0 aboli%$ at ! hot-wat] temp]ature ( #ee;,c4 ,,table ,,%[+ ,,dim9ution ,,( ,,response ,,) ,,increas+ ,,temp]ature 7#ja,volt #ce;divisions7 ,temp]ature ,response #bj #ba #cj #ge #dj #ee #ej #d #fe #c ,9 radi%es response disappe>$ completely at #ee;,c41 b ) cel]y1 heat$ 9 ! mann] describ$1 ,i c\ld n obta9 its entire abolition at #fj;,c4 or ev5 high]4 ,a noticeable circum/ance1 h[ev]1 0 ! prolongation ( ! p]iod ( recov]y at ^! high temp]atures4 ,i soon und]/ood ! reason ( ?is app>5t anomaly4 ,! me?od adopt$ 9 ! pres5t case 0 t ( dry heat+1 :]eas ! previ\s exp]im5ts _h be5 c>ri$ on by ! use ( hot wat]4 ,x is well kn[n t "o c /& a temp]ature ( #ajj;,c4 )\t ill effects 9 ! hot-air *amb] ( a ,turki% ba?1 :ile imm]sion 9 wat] at #ajj;,c4 w\ld be fatal4 ,9 ord] to f9d out :e!r subjection to hot wat] w\ld kill ! cel]y-/alk1 ,i took x out & plac$ x = five m9utes 9 wat] at #ee;,c4 ,?is1 z w be se5 f ! record tak5 aft]w>ds1 effectively kill$ ! plant 7fig4#ch1 w74 ,illu/ration3 ,,fig4#ci4--;,,effect ,,( ,,ris+ ,,& ,,fall+ ,,temp]ature ,,on ,,! ,,response ,,( ,,scot* ,,kale ,increas$ s5sitiv5ess z aft]-effect ( temp]ature v>iation4--,a v curi\s effect ( temp]ature v>iation is ! m>k$ increase ( s5sitiv5ess :i* (t5 appe>s z its aft]-effect4 ,i notic$ ?is fir/ 9 a s]ies ( obs]vations :]e records 7 tak5 dur+ ! rise ( temp]ature & cont9u$ :ile ! temp]ature 0 fall+ 7fig4#ci74 ,! temp]ature 0 adju/$ by electric heat+4 ,x 0 f\nd t ! responses 7 m>k$ly enhanc$ dur+ cool+1 z comp>$ ) responses giv5 at ! same temp]atures :ile w>m+ 7see table74 ,temp]ature v>iation ?us seems to h a /imulat+ effect on response1 by increas+ molecul> mobility 9 "s way4 ,! second record 7fig4#dj7 %[s ! v>iation ( response 9 ,eu*>is lily 7#a7 dur+ ! rise1 & 7#b7 dur+ ! fall ( temp]ature4 ,fig4#da gives a curve ( v>iation ( response dur+ ! rise & fall ( temp]ature4 ,,table ,,%[+ ,,! ,,v>iation ,,( ,,response ,,9 ,,scot* ,,kale ,,dur+ ,,! ,,rise ,,& ,,fall ,,( ,,temp]ature ,temp]ature ,response ,response ,temp]ature ris+ ,temp]ature fall+ #ai;,c4 #dg dns4 -- #be #bd -- #cj #aa #bc dns4 #ej #h #af #gj v #g -- ----- ,illu/ration3 ,,fig4#dj4--,,records ,,( ,,responses ,,9 ,,eu*>is ,,lily ,,dur+ ,,rise ,,& ,,fall ,,( ,,temp]ature ,/imulus con/ant1 appli$ at int]vals ( "o m9ute4 ,! temp]ature ( plant-*amb] gradually rose on />t+ curr5t 9 ! heat+ coil2 on break+ curr5t1 ! temp]ature fell gradually4 ,temp]ature correspond+ to ea* record is giv5 bel[4 ,temp]ature ris+3 7#a7bj1 7#b7bj1 7#c7bb1 7#d7ch1 7#e7ec1 7#f7fh1 7#g7fe4 ,temp]ature fall+3 7#h7fj1 7#i7ea1 7#aj7de1 7#aa7dj1 7#ab7ch4 ,po9t ( temp]ature maximum4--,we h se5 h[1 9 cases ( l[]$ temp]ature1 response is aboli%$ e>li] 9 plants l ,eu*>is1 :i* are affect$ by cold1 ?an 9 ! h>di] plants su* z ,holly & ,ivy4 ,plants aga9 are unequally affect$ z reg>ds ! upp] range4 ,9 ! case ( ,scot* kale1 = in/ance1 response disappe>s aft] t5 m9utes ( wat] temp]ature ( ab\t #ee;,c41 b ) ,eu*>is fairly m>k$ response c /ill be obta9$ aft] su* imm]sion & does n disappe> till x has be5 subject$ = t5 m9utes to hot wat]1 at a temp]ature ( #fe;,c4 or ev5 high]4 ,! reason ( ?is great p[] ( resi/ance to heat is probably f\nd 9 ! fact t ! ,eu*>is is a tropical plant1 & is gr[n1 9 ?is c\ntry1 9 hot-h\ses :]e a comp>atively high temp]ature is ma9ta9$4 ,illu/ration3 ,,fig4#da4--;,,curve ,,%[+ ,,v>iation ,,( ,,response ,,9 ,,eu*>is ,,) ,,! ,,rise ,,& ,,fall ,,( ,,temp]ature ,! effect ( /eam4--,i next wi%$ to obta9 a cont9u\s record by :i* ! effects ( sudd5ly increas$ temp]atures1 culm9at+ 9 ! dea? ( ! plant1 might be made evid5t4 ,= ?is purpose ,i m\nt$ ! plant 9 ! glass *amb]1 into :i* /eam c\ld be introduc$4 ,i _h *os5 a specim5 :i* gave regul> response4 ,on ! introduction ( /eam1 ) ! consequ5t sudd5 increase ( temp]ature1 !re 0 a transitory augm5tation ( excitability4 ,b ?is quickly disappe>$1 & 9 five m9utes ! plant 0 effectively kill$1 z w be se5 graphically illu/rat$ 9 ! record 7fig4#db74 ,illu/ration3 ,,fig4#db4--;,,effect ,,( ,,/eam ,,9 ,,kill+ ,,response ,! two records to ! left exhibit normal response at #ag;,c4 ,sudd5 w>m+ by /eam produc$ at fir/ an increase ( response1 b five m9utes exposure to /eam kill$ ! plant 7c>rot7 & aboli%$ ! response4 ,vibrational /imulus ( #cj appli$ at int]vals ( "o m9ute2 v]tical l9e #avolt4 ,x w ?us be se5 t ^? modifications ( vital activity :i* are produc$ 9 plants by temp]ature v>iation c be v accurately gaug$ by electric response4 ,inde$ x may be said t !re is no o!r me?od by :i* ! mom5t ( cessation ( vitality c be s satisfactorily di/+ui%$4 ,ord9>ily1 we are able to judge t a plant has di$1 only aft] v>i\s indirect effects ( dea?1 su* z )]+1 h begun to appe>4 ,b 9 ! electric response we h an imm$iate indication ( ! arre/ ( vitality1 & we are !reby enabl$ to det]m9e ! dea?-po9t1 :i* x is impossible to d by any o!r means4 ,x may be m5tion$ "h t ! explanation sugge/$ by ,kunkel1 ( ! response be+ due to movem5t ( wat] 9 ! plant1 is inadequate4 ,= 9 t case we %\ld expect a def9ite /imulation to be "u all conditions foll[$ by a def9ite electric response1 ^: int5sity & sign %\ld rema9 inv>iable4 ,b we f9d1 in/ead1 ! response to be pr(\ndly modifi$ by any influ5ce :i* affects ! vitality ( ! plant4 ,= in/ance1 ! response is at its maximum at an optimum temp]ature1 a rise ( a few degrees produc+ a pr(\nd depression2 ! response disappe>s at ! maximum & m9imum temp]atures1 & is reviv$ :5 br\ght back to ! optimum4 ,an/hetics & poisons aboli% ! response4 ,aga91 we h ! response und]go+ an actual rev]sal :5 ! tissue is /ale4 ,all ^! facts %[ t m]e movem5t ( wat] c\ld n be ! effective cause ( plant response4 ,,*apt] ,,ix ,,plant ,,response--,,effect ,,( ,,an,,/hetics ,,& ,,poisons ,effect ( an/hetics1 a te/ ( vital "* ( response--,effect ( *lor(orm--,effect ( *loral--,effect ( =mal9--,me?od 9 :i* response is unaffect$ by v>iation ( resi/ance--,advantage ( block me?od--,effect ( dose4 ,! mo/ important te/ by :i* vital ph5om5a are di/+ui%$ is ! influ5ce on response ( n>cotics & poisons4 ,= example1 a n]ve :5 n>cotis$ by *lor(orm exhibits a dim9i%+ response z ! action ( ! an/hetic proce$s4 7,see bel[1 fig4#dc47 ,simil>ly1 v>i\s poisons h ! effect ( p]man5tly aboli%+ all response4 ,?us a n]ve is kill$ by /rong alkalis & /rong acids4 ,i h already %[n h[ plants :i* previ\sly gave /rong response did n1 aft] application ( an an/hetic or poison1 give any response at all4 ,9 ^! cases x 0 ! la/ /age only t c\ld be obs]v$4 ,b x appe>$ important to be able to trace ! gr[+ effect ( an/hetisation or poison+ ?r\gh\t ! process4 ,!re 71 h[ev]1 two conditions :i* x at fir/ appe>$ difficult to meet4 ,fir/ x 0 necess>y to f9d a specim5 :i* w\ld normally exhibit no fatigue1 & give rise = a long "t to a uni=m s]ies ( response4 ,! imm$iate *anges made 9 ! response1 9 consequ5ce ( ! application ( *emical reag5ts1 c\ld !n be demon/rat$ 9 a /rik+ mann]4 ,& ) a little tr\ble1 specim5s c be secur$ 9 :i* p]fect regul>ity ( response is f\nd4 ,! record giv5 9 fig4#af1 obta9$ ) a specim5 ( radi%1 %[s h[ possible x is to secure plants 9 :i* response is absolutely regul>4 ,i subject$ ?is to uni=m /imulation at int]vals ( "o m9ute1 dur+ half an h\r1 )\t detect+ ! lea/ v>iation 9 ! responses4 ,b x is ( c\rse easi] to f9d o!rs 9 :i* ! responses z a :ole may be tak5 z regul>1 ?\gh !re may be slight rhy?mic fluctuations4 ,& ev5 9 ^! cases ! effect ( reag5ts is too m>k$ & sudd5 to escape notice4 ,illu/ration3 ,,fig4#dc4--;,,effect ,,( ,,*lor(orm ,,on ,,n]ve ,,response 7,,wall]7 ,= ! obta9+ ( con/ant & /rong response ,i f\nd ! be/ mat]ials to be c>rot & radi%1 select$ individuals f :i* gave mo/ satisfactory results4 ,! c>rots 7 at _! be/ 9 ,augu/ & ,septemb]1 aft] :i* _! s5sitiv5ess rapidly decl9$4 ,lat]1 be+ oblig$ to seek = o!r specim5s1 ,i came ^u radi%1 :i* gave good results 9 ! e>ly "p ( ,novemb]2 b ! sett+-9 ( ! fro/ _h a prejudicial effect on its responsiv5ess4 ,less p]fect ?an ^!1 b /ill s]viceable1 are ! leaf-/alks ( turnip & caulifl[]4 ,9 ^! ! successive responses z a :ole may be reg>d$ z regul>1 ?\gh a curi\s alt]nation is sometimes notic$1 :i*1 h[ev]1 has a regul>ity ( its own4 ,my second misgiv+ 0 z to :e!r ! action ( reag5ts w\ld be suffici5tly rapid to display itself )9 ! "t limit ( a photographic record4 ,?is w\ld ( c\rse dep5d 9 turn ^u ! rapidity ) :i* ! tissues ( ! plant c\ld absorb ! reag5t & be affect$ by x4 ,x 0 a surprise to me to f9d t1 ) good specim5s1 ! effect 0 manife/$ 9 ! c\rse ( s %ort a "t z a m9ute or s4 ,effect ( *lor(orm4--,9 /udy+ ! effect ( *emical reag5ts 9 plants1 ! me?od is precisely simil> to t employ$ ) n]ve2 t is to say1 :]e vap\r ( *lor(orm is us$1 x is bl[n into ! plant *amb]4 ,9 cases ( liquid reag5ts1 !y are appli$ on ! po9ts ( contact ,a & ,b & _! close neighb\rhood4 ,! mode ( exp]im5t 0 7#a7 to obta9 a s]ies ( normal responses to uni=m /imuli1 appli$ at regul> int]vals ( "t1 say "o m9ute1 ! record be+ tak5 ! :ile on a photographic plate4 7#b7 ,)\t int]rupt+ ?is proc$ure1 ! an/hetic ag5t1 vap\r ( *lor(orm1 0 bl[n into ! clos$ *amb] conta9+ ! plant4 ,x w be se5 h[ rapidly *lor(orm produces depression ( response 7fig4#dd71 & h[ ! effect gr[s ) "t4 ,9 ^! exp]im5ts ) plants1 ! same curi\s %ift+ ( ! z]o l9e is sometimes notic$ z 9 n]ve :5 subject$ simil>ly to ! action ( reag5ts4 ,?is is a po9t ( m9or importance1 ! ess5tial po9t to be notic$ be+ t ! responses are rapidly r$uc$4 ,illu/ration3 ,,fig4#dd4--;,,effect ,,( ,,*lor(orm ,,on ,,responses ,,( ,,c>rot ,/imuli ( #be vibration at int]vals ( "o m9ute4 ,effects ( *loral & =mal94--,i give bel[ 7figs4 #de1 #df7 two sets ( records1 "o = ! reag5t *loral & ! o!r = =mal94 ,! reag5ts 7 appli$ 9 ! =m ( a solution on ! tissue at ! two lead+ contacts1 & ! contigu\s surface4 ,! rhy?mic fluctuation 9 ! normal response %[n 9 fig4#de is int]e/+4 ,! abrupt decl9e1 )9 a m9ute ( ! application ( *loral1 is also extremely well m>k$4 ,illu/ration3 ,,fig4#de4--;,,action ,,( ,,*loral ,,hydrate ,,on ,,! ,,responses ,,( ,,leaf-,,/alk ,,( ,,caulifl[] ,vibration ( #be at int]vals ( "o m9ute4 ,illu/ration3 ,,fig4#df4--;,,action ,,( ,,=mal9 7,,radi%7 ,response unaffect$ by v>iation ( resi/ance4--,9 ord] to br+ out cle>ly ! ma9 ph5om5a1 ,i h po/pon$ till n[ ! consid]ation ( a po9t ( "s difficulty4 ,to det]m9e ! influ5ce ( a reag5t 9 modify+ ! excitability ( ! tissue1 we rely ^u its effect 9 exalt+ or depress+ ! responsive ,e4,m4 v>iation4 ,we read ?is effect by means ( galvanometric deflections4 ,& if ! resi/ance ( ! circuit rema9$ con/ant1 !n an increase ( galvanomet] deflection w\ld accurately indicate a height5$ or depress$ ,e4,m4 response1 due to great] or less excitability ( tissue caus$ by ! reag5t4 ,b1 by ! introduction ( ! *emical reag5t1 ! resi/ance ( ! tissue may und]go *ange1 & ow+ to ?is cause1 modification ( response z read by ! galvanomet] may be produc$ )\t any ,e4,m4 v>iation4 ,! obs]v$ v>iation ( response may ?us be p>tly ow+ to "s unkn[n *ange ( resi/ance1 z well z to t ( ! ,e4,m4 v>iation 9 response to /imulus4 ,we may h[ev] discrim9ate z to h[ mu* ( ! obs]v$ *ange is due to v>iation ( resi/ance by comp>+ ! deflections produc$ 9 ! galvanomet] by ! action ( a def9ite small ,e4,m4,f4 be=e & aft] ! introduction ( ! reag5t4 ,if ! deflections be ! same 9 bo? cases1 we "k t ! resi/ance has n v>i$4 ,if !re h be5 any *ange1 ! v>iation ( deflection w %[ ! am\nt1 & we c make all[ance accord+ly4 ,i h h[ev] adopt$ ano!r me?od1 by :i* all necessity ( correction is obviat$1 & ! galvanometric deflections simply give ,e4,m4 v>iations1 unaffect$ by any *ange 9 ! resi/ance ( ! tissue4 ,?is is done by int]pos+ a v l>ge & con/ant resi/ance 9 ! ext]nal circuit & !reby mak+ o!r resi/ances negligible4 ,an example w make ?is po9t cle>4 ,tak+ a c>rot z ! vegetable tissue1 ,i f\nd its resi/ance plus ! resi/ance ( ! non-pol>isable electrode equal to #bj1jjjohms4 ,! introduction ( a *emical reag5t r$uc$ x to #ai1jjjohms4 ,! resi/ance ( ! galvanomet] is equal to #a1jjjohms4 ,! high ext]nal resi/ance 0 #a1jjj1jjjohms4 ,! v>iation ( resi/ance produc$ 9 ! circuit w\ld !re=e be #a1jjj 9 7#a1jjj1jjjai1jjja1jjj7 or "o "p 9 #a1jbj4 ,!re=e ! v>iation ( galvanometric deflection due to *ange ( resi/ance w\ld be less ?an "o "p 9 a ?\s& 7cf4 fig4#di74 ,! advantage ( ! block me?od4--,9 ^! inve/igations ,i h us$ ! block me?od1 in/ead ( t ( negative v>iation1 & ,i may "h draw att5tion to ! advantages :i* x (f]s4 ,9 ! me?od ( negative v>iation1 "o contact be+ injur$1 ! *emical reag5ts act on injur$ & un9jur$ unequally1 & x is conceivable t by ?is unequal action ! re/+ diff]5ce ( pot5tial may be alt]$4 ,b ! int5sity ( response 9 ! me?od ( injury dep5ds on ?is re/+ diff]5ce4 ,x is ?us hypo!tically possible t on ! me?od ( negative v>iation !re might be *anges 9 ! responses caus$ by v>iation ( ! re/+ diff]5ce1 & n necess>ily due to ! /imulat+ or depress+ effect ( ! reag5t on ! tissue4 ,b by ! block me?od ! two contacts are made ) un9jur$ surfaces1 & ! effect ( reag5ts on bo? is simil>4 ,?us no advantage is giv5 to "o contact ov] ! o!r4 ,! *anges n[ detect$ 9 response are !re=e due to no adv5titi\s circum/ance1 b to ! reag5t itself4 ,if fur!r v]ification be desir$ z to ! effect ( ! reag5t1 we c obta9 x by alt]nate /imulation ( ! ,a & ,b ends4 ,bo? ends w !n %[ ! giv5 *ange4 ,i give bel[ a record ( responses giv5 by two ends ( leaf-/alk ( turnip1 /imulat$ alt]nately 9 ! mann] describ$4 ,! /alk us$ 0 slightly conical1 & ow+ to ?is diff]5ce betwe5 ! ,a & ,b ends ! responses giv5 by "o end 7 slightly diff]5t f ^? giv5 by ! o!r1 ?\gh ! /imuli 7 equal4 ,a few drops ( #ajp]c5t4 solution ( ,na,o,h 0 appli$ to bo? ! ends4 ,x w be se5 h[ quickly ?is reag5t aboli%$ ! response ( bo? ends 7fig4#dg74 ,illu/ration3 ,,fig4#dg4--;,,abolition ,,( ,,response ,,at ,,bo? ,a ,,& ,b ,,ends ,,by ,,! ,,action ,,( ,na,o,h ,/imuli ( #cj vibration 7 appli$ at int]vals ( "o m9ute to ,a & ,b alt]nately4 ,response 0 completely aboli%$ tw5ty-f\r m9utes aft] application ( ,na,o,h4 ,effect ( dose4--,x is sometimes f\nd t :ile a reag5t acts z a poison :5 giv5 9 l>ge quantities1 x may act z a /imulant 9 small doses4 ,( ! two foll[+ records fig4#dh %[s ! slight /imulat+ effect ( v dilute ,,koh1 & fig4#di exhibits ne>ly complete abolition ( response by ! action ( ! same reag5t :5 giv5 9 /rong] doses4 ,illu/ration3 ,,fig4#dh4--,,/imulat+ ,,action ,,( ,,v ,,dilute ,,koh ,s we see t1 judg$ by ! f9al crit]ion ( ! effect produc$ by an/hetics & poisons1 ! plant response fulfils ! te/ ( vital ph5om5on4 ,9 previ\s *apt]s we h f\nd t 9 ! matt] ( response by negative v>iation1 ( ! pres5ce or abs5ce ( fatigue1 ( ! relation betwe5 /imulus & response1 ( modification ( response by high & l[ temp]atures1 & ev5 9 ! matt] ( occasional abnormal v>iations su* z positive response 9 a modifi$ tissue1 !y 7 /rictly correspond5t to simil> ph5om5a 9 animal tissues4 ,! rema9+ te/1 ( ! influ5ce ( *emical reag5ts1 hav+ n[ be5 appli$1 a complete p>allelism may be held to h be5 e/abli%$ betwe5 plant response on ! "o h&1 & t ( animal tissue on ! o!r4 ,illu/ration3 ,,fig4#di4--,,ne>ly ,,complete ,,abolition ,,( ,,response ,,by ,,/rong ,,koh ,! two v]tical l9es are galvanomet] deflections due to #avolt1 be=e & aft] ! application ( reag5t4 ,x w be notic$ t ! total resi/ance rema9s un*ang$4 ,,*apt] ,x ,,response ,,9 ,,metals ,is response f\nd 9 inorganic sub/ances8--,exp]im5t on t91 block me?od--,anomalies ( exi/+ t]m9ology--,response by me?od ( depression--,response by me?od ( exaltation4 ,we h n[ se5 t ! electrical sign ( life is n conf9$ to animals1 b is also f\nd 9 plants4 ,& we h se5 h[ electrical response s]ves z an index to ! vital activity ( ! plant1 h[ ) ! arre/ ( ?is vital activity electrical response is also arre/$ tempor>ily1 z 9 ! case among/ o!rs ( an/hetic action1 & p]man5tly1 = in/ance "u ! action ( poisons4 ,?us liv+ tissues--bo? animal & vegetable--may pass f a responsive to an irresponsive condition1 f :i* latt] !re may or may n be subsequ5t revival4 ,hi!rto1 z already said1 electrical response 9 animals has be5 reg>d$ z a purely physiological ph5om5on4 ,we h prov$ by v>i\s te/s t response 9 plants is ( ! same "*4 ,& we h se5 t by physiological ph5om5a are g5]ally und]/ood ^? ( :i* no physical explanation c be (f]$1 !y be+ suppos$ to be due to ! play ( "s unkn[n vital =ce exi/+ 9 liv+ sub/ances & giv+ rise to electric response to /imulation z "o ( its manife/ations4 ,is response f\nd 9 inorganic sub/ances8#ad--;,x is n[ = u1 h[ev]1 to exam9e into ! alleg$ sup]-physical "* ( ^! ph5om5a by /imulat+ inorganic sub/ances & discov]+ :e!r !y d or d n give rise to ! same electrical mode ( response :i* 0 suppos$ to be ! special *>act]i/ic ( liv+ sub/ances4 ,we %all use ! same app>atus & ! same mode ( /imulation z ^? employ$ 9 obta9+ plant response1 m]ely sub/itut+1 = ! /alk ( a plant1 a metallic wire1 say 't9' 7fig4#ej74 ,any o!r metal c\ld be us$ in/ead ( t94 ,exp]im5t on t91 block me?od4--,let u !n take a piece ( t9 wire#ae f :i* all /ra9s h be5 previ\sly remov$ by anneal+1 & hold x clamp$ 9 ! middle at ,c4 ,if ! /ra9s h be5 successfully remov$ ,a & ,b w be f\nd iso-electric1 & no curr5t w pass ?r\gh ! galvanomet]4 ,if ,a & ,b are n exactly simil>1 !re w be a slight curr5t4 ,b ?is w n mat]ially affect ! results to be describ$ pres5tly1 ! slight exi/+ curr5t m]ely add+ itself algebraically to ! curr5t ( response4 ,if we n[ /imulate ! end ,a by taps1 or bett] /ill by torsional vibration1 a transitory 'curr5t ( action' w be f\nd to fl[ 9 ! wire f ,b to ,a1 f ! un/imulat$ to ! /imulat$1 & 9 ! galvanomet] f ! /imulat$ to ! un/imulat$4 ,/imulation ( ,b w give rise to a curr5t 9 an opposite direction4 ,illu/ration3 ,,fig4#ej4--;,,electric ,,response ,,9 ,,metals 7a7 ,me?od ( block2 7b7 ,equal & opposite responses :5 ! ends ,a & ,b are /imulat$2 ! dott$ portions ( ! curves %[ recov]y2 7c7 ,balanc+ effect :5 bo? ! ends are /imulat$ simultane\sly4 ,exp]im5t to exhibit ! balanc+ effect4--,if ! wire has be5 c>efully anneal$1 ! molecul> condition ( its diff]5t portions is f\nd to be approximately ! same4 ,if su* a wire be held at ! 'balanc+ po9t' 7:i* is at or ne> ! middle7 by ! clamp1 & a quick vibration1 say1 ( #ij be giv5 to ,a1 an upw>d deflection w be produc$2 if a vibration ( #ij be giv5 to ,b1 !re w be an equal d[nw>d deflection4 ,if n[ bo? ! ends ,a & ,b are vibrat$ simultane\sly1 ! responsive ,e4,m4 v>iation at ! two ends w cont9u\sly balance ea* o!r & ! galvanomet] spot w rema9 quiesc5t 7fig4#cj1 ,a1 ,b1 ,r74 ,?is balance w be /ill ma9ta9$ :5 ! block is remov$ & ! wire is vibrat$ z a :ole4 ,x is to be rememb]$ t ) ! l5g? ( wire con/ant1 ! int5sity ( /imulus increases ) ! amplitude ( vibration4 ,aga91 keep+ ! amplitude con/ant1 ! int5sity ( /imulus is increas$ by %ort5+ ! wire4 ,h5ce x w be se5 t if ! clamp be %ift$ f ! balanc+ po9t t[>ds ,a1 simultane\s vibration ( ,a & ,b ?r\gh #ij w n[ give a resultant upw>d deflection1 %[+ t ! ,a response is n[ relatively /rong]4 ,?us keep+ ! re/ ( ! circuit unt\*$1 m]ely mov+ ! clamp f ! left1 pa/ ! balanc+ po9t to ! "r1 we get ei!r a positive1 or z]o1 or negative1 resultant effect4 ,9 t9 ! curr5t ( response is f ! less to ! m excit$ po9t4 ,9 ! ret9a also1 we f\nd ! curr5t ( action fl[+ f ! less /imulat$ to ! m /imulat$1 & z t is kn[n z a positive response1 we %all consid] ! normal response ( t9 to be 9 l mann] positive4 ,j z ! response ( ret9a or n]ve1 "u c]ta9 molecul> conditions1 und]goes rev]sal1 ! positive be+ !n conv]t$ into negative1 & negative into positive1 s x w be %[n t ! response 9 metallic wires "u c]ta9 conditions is f\nd to und]go rev]sal4 ,anomalies ( pres5t t]m9ology4--,:5 !re is no curr5t ( injury1 a p>ticul> curr5t ( response c h>dly be call$ a negative1 or positive1 v>iation4 ,su* nom5clature is purely arbitr>y1 & leads1 z w be %[n1 to mu* confusion4 ,a m def9ite t]m9ology1 free f misund]/&+1 w\ld be1 z already said1 to reg>d ! curr5t t[>ds ! m /imulat$ z positive1 & t t[>ds ! less /imulat$1 9 tissue or wire1 z negative4 ,! /imulat$ end ( t91 say ! end ,a1 ?us becomes z9coid1 i4e4 ! curr5t ?r\gh ! electrolyte 7non-pol>isable electrodes ) int]pos$ galvanomet]7 is f ,a to ,b1 & ?r\gh ! wire1 f ! less /imulat$ ,b to ! m /imulat$ ,a4 ,conv]sely1 :5 ,b is /imulat$1 ! action curr5t fl[s r\nd ! circuit 9 an opposite direction4 ,?is positive is ! mo/ usual =m ( response1 b !re are cases :]e ! response is negative4 ,9 ord] to %[ t normally speak+ a /imulat$ wire becomes z9coid1 & also to %[ once m ! anomalies into :i* we may fall by adopt+ no m def9ite t]m9ology ?an t ( negative v>iation1 ,i h devis$ ! foll[+ exp]im5t 7fig4#ea74 ,let u take a b>1 "o half ( :i* is z9c & ! o!r half copp]1 clamp$ 9 ! middle1 s t a di/urbance produc$ at "o end may n rea* ! o!r2 ! two ends are connect$ to a galvanomet] ?r\gh non-pol>isable electrodes4 ,! curr5t ?r\gh ! electrolyte 7non-pol>isable electrodes & int]pos$ galvanomet]7 w !n fl[ f left to "r4 ,we mu/ rememb] t metals "u /imulation g5]ally become1 9 an electrical s5se1 m z9c-l4 ,on vibrat+ ! copp] end 7inasmu* z copp] w\ld !n become m z9c-l7 ! diff]5ce ( pot5tial betwe5 z9c & copp] ought to be dim9i%$1 & ! curr5t fl[+ 9 ! circuit w\ld !re=e be less5$4 ,b vibration ( ! z9c end ought to increase ! pot5tial diff]5ce1 & !re ought to be !n an increase ( curr5t dur+ /imulation ( z9c4 ,illu/ration3 ,,fig4#ea4--;,,curr5t ,,( ,,response ,,t[>ds ,,! ,,/imulat$ ,,end ,h5ce :5 ,cu /imulat$3 action curr5t --1 normal ,e4,m4,f4 dim9i%$ 7#he-jji7 ,v4 ,:5 ,zn /imulat$3 action curr5t --1 normal ,e4,m4,f4 increas$ 7#hejac7 ,v4 ,9 ! p>ticul> exp]im5t ( fig4#ea1 ! ,e4,m4,f4 betwe5 ! z9c & copp] ends 0 f\nd to be #hevolt4 ,?is 0 balanc$ by a pot5tiomet] arrangem5t1 s t ! galvanomet] spot came to z]o4 ,on vibrat+ ! z9c wire1 a deflection ( #cc;dns4 0 obta9$1 9 a direction :i* %[$ an increase ( ,e4,m4,f4 ,on /opp+ ! vibration1 ! spot ( light came back to z]o4 ,on n[ vibrat+ ! copp] wire1 a deflection ( #bc;dns4 0 obta9$ 9 an opposite direction1 %[+ a dim9ution ( ,e4,m4,f4 ,?is transitory responsive v>iation disappe>$ on ! cessation ( di/urbance4 ,by di/urb+ ! balance ( ! pot5tiomet]1 ! galvanomet] deflection due to a kn[n increase ( ,e4,m4,f4 0 f\nd f :i* ! absolute ,e4,m4 v>iation caus$ by di/urbance ( copp] or z9c 0 det]m9$4 ,x 0 ?us f\nd t /imulation ( z9c _h increas$ ! ,p4,d4 by fifte5 p>ts 9 #a1jjj1 :]eas /imulation ( copp] _h decreas$ x by elev5 p>ts 9 #a1jjj4 ,accord+ to ! old t]m9ology1 ! response due to /imulation ( z9c w\ld h be5 reg>d$ z positive v>iation1 t ( copp] negative4 ,! responses h[ev] are n ess5tially opposite 9 "*1 ! action curr5t 9 ! b> be+ 9 bo? cases t[>ds ! m excit$4 ,= ?is reason x w\ld be pref]able1 z already said1 to employ ! t]ms positive & negative 9 ! s5se ,i h sugge/$1 i4e4 positive1 :5 ! curr5t 9 ! act$ sub/ance is t[>ds ! m excit$1 & negative1 :5 t[>ds ! less excit$4 ,! me?od ( block is1 z ,i h already %[n1 ! mo/ p]fect = ! /udy ( ^! responses4 ,9 ! exp]im5t fig4#ej1 if ! block is aboli%$ & ! wire is /ruck 9 ! middle1 a wave ( molecul> di/urbance w rea* ,a & ,b4 ,! me*anical & ! att5dant electrical di/urbance w at ^! po9ts rea* a maximum & !n gradually subside4 ,! resultant effect 9 ! galvanomet] w be due to ,e,a-,e,b :5 ,e,a & ,e,b are ! electrical v>iations produc$ at ,a & ,b by ! /imulus4 ,! electric *anges at ,a & ,b w cont9u\sly balance ea* o!r1 & ! resultant effect on ! galvanomet] w be z]o3 7a7 if ! excit+ di/urbance rea*es ,a & ,b at ! same "t & ) ! same int5sity2 7b7 if ! molecul> condition is simil> at ! two po9ts2 & 7c7 if ! rate ( rise & subsid5ce ( excitation is ! same at ! two po9ts4 ,9 ord] t a resultant effect may be exhibit$ 9 ! galvanomet]1 matt]s h to be s arrang$ t ! di/urbance may rea* "o po9t1 say ,a1 & n ,b1 & vice v]sa4 ,?is 0 accompli%$ by means ( a clamp1 9 ! me?od ( block4 ,aga9 a resultant diff]5tial action may be obta9$ ev5 :5 ! di/urbance rea*es bo? ,a & ,b1 if ! electrical excitability ( "o po9t is exalt$ or depress$ by physical or *emical means4 ,we %all 9 ,*ap4 ,,xvi /udy 9 detail ! effect ( *emical reag5ts 9 produc+ ! enhancem5t or depression ( excitability4 ,!re are ?us two o!r means ( obta9+ a resultant effect--7#b7 by ! me?od ( relative depression1 7#c7 by ! me?od ( relative exaltation4 ,electric response by me?od ( depression4--,we may ?us by r$uc+ or aboli%+ ! excitability ( "o end by means ( suitable *emical reag5ts 7s-call$ me?od ( injury7 obta9 response 9 metals )\t a block4 ,! entire l5g? ( ! wire may !n be /imulat$ & a resultant response w be produc$1 ow+ to ! diff]5ce betwe5 ! excitability ( ! two ends4 ,a piece ( t9 wire is tak51 & "o normal contact is made at ,a 7/rip ( clo? moi/5$ ) wat]1 or v dilute salt solution74 ,! excitability ( ,b is depress$ by a few drops ( /rong pota% or oxalic acid4 ,by ! application ( ! latt] !re w be a small ,p4,d4 betwe5 ,a & ,b2 ?is w simply produce a displacem5t ( z]o4 ,by means ( a pot5tiomet] ! galvanomet] spot may be br\ght back to ! orig9al position4 ,! %ift+ ( ! z]o w n affect ! g5]al result4 ,! effect ( me*anical /imulus is to produce a transi5t electro-motive response1 :i* w be sup]pos$ algebraically on ! exi/+ ,p4,d4 ,! deflection w take place f ! modifi$ z]o to :i* ! spot returns dur+ recov]y4 ,on n[ /imulat+ ! wire z a :ole by1 say1 torsional vibration1 ! curr5t ( response w be f\nd t[>ds ! m excitable1 i4e4 f ,b to ,a 7fig4#eb1 a74 ,illu/ration3 ,,fig4#eb4--,,response ,,by ,,me?od ,,( ,,depression 7,,)\t ,,block7 ,:5 ! wire is /imulat$ z a :ole ! curr5t ( response is t[>ds ! m excitable4 ,9 7a7 ,a is a normal contact1 ,b has be5 depress$ by oxalic acid2 curr5t ( response is t[>ds ! m excitable ,a4 ,9 7b7 ! same wire is us$1 only ,a is depress$ by oxalic acid & a normal contact is made at a fre% po9t ,b'1 a little to ! left ( ,b 9 7a74 ,curr5t ( response is n[ f ,a t[>ds ! m excitable ,b'4 ,a corroborative rev]sal exp]im5t may next be made on ! same piece ( wire4 ,! normal contact1 ?r\gh wat] or salt solution1 is n[ made at ,b'1 a little to ! left ( ,b4 ,! excitability ( ,a is n[ depress$ by oxalic acid4 ,on /imulation ( ! :ole wire1 ! curr5t ( response w n[ be f\nd to fl[ 9 an opposite direction--i4e4 f ,a to ,b'--b /ill f ! relatively less to ! relatively m excitable 7fig4#eb1 b74 ,f ^! exp]im5ts x w be se5 h[ 9 "o id5tical piece ( wire ! responsive curr5t fl[s n[ 9 "o direction & !n 9 ! o!r1 9 absolute con=mity ) !oretical consid]ations4 ,me?od ( exaltation4--,a /ill m /rik+ corroboration ( ^! results may1 h[ev]1 be obta9$ by ! conv]se process ( relative exaltation ( ! responsiv5ess ( "o contact4 ,?is may be accompli%$ by t\*+ "o contact1 say ,b1 ) a reag5t :i* l ,na#b;,,co#c exalts ! electric excitability4 ,on /imulation ( ! wire1 ! curr5t ( response is t[>ds ! m excitable ,b 7fig4#ec74 ,illu/ration3 ,,fig4#ec4--,,me?od ,,( ,,exaltation ,! contact ,b is made m excitable by *emical /imulant 7,na#b;,,co#c74 ,! curr5t ( response is t[>ds ! m excitable ,b4 ,i give f\r records 7fig4#ed7 :i* w cle>ly exhibit ! responses z obta9$ by ! me?ods ( relative depression or exaltation4 ,9 7a7 ,b is t\*$ ) ! excitant ,na#b;,,co#c1 a p]man5t curr5t fl[s f ,a to ,b1 response to /imulus is 9 ! same direction z ! p]man5t curr5t 7positive v>iation74 ,9 7b7 ,b is t\*$ ) a trace ( ! depressant oxalic acid1 ! p]man5t curr5t is 9 ! same direction z be=e1 b ! curr5t ( response is 9 ! opposite direction 7negative v>iation74 ,9 7c7 ,b is t\*$ ) dilute ,,kho1 ! response is exhibit$ by a positive v>iation4 ,9 7d7 ,b is t\*$ ) /rong ,,kho1 ! response is n[ exhibit$ by a negative v>iation4 ,! la/ two results1 app>5tly anomal\s1 are due to ! fact1 :i* w be demon/rat$ lat]1 t ,,kho 9 m9ute quantities is an excitant1 :ile 9 l>ge quantities x is a depressant4 ,illu/ration3 ,,fig4#ed ---------------------------------------- ,curr5t ,p]man5t ( ,curr5t ,response ---------------------------------------- ,b treat$ ) sodium c>bonate4 -- -- ---------------------------------------- ,b treat$ ) oxalic acid -- -- ---------------------------------------- ,b treat$ ) v dilute pota% -- -- ---------------------------------------- ,b treat$ ) /rong pota% -- -- ---------------------------------------- ,curr5t ( response is always t[>ds ! m excitable po9t4 7a7 ,response :5 ,b is treat$ ) sodium c>bonate4--,an app>5t positive v>iation4 7b7 ,response :5 ,b is treat$ ) oxalic acid4--,an app>5t negative v>iation4 7c7 ,response :5 ,b is treat$ ) v dilute pota%4--,positive v>iation4 7d7 ,response :5 ,b is treat$ ) /rong pota%4--,negative v>iation4 ,! response is up :5 ,b is m excitable1 & d[n :5 ,a is m excitable4 ,l9es ?us ------ indicate deflection due to p]man5t curr5t4 ,we h ?us se5 t we may obta9 response 7#a7 by block me?od1 7#b7 by ! me?od ( injury1 or relative depression ( responsiv5ess ( "o contact1 & 7#c7 by ! me?od ( relative exaltation ( responsiv5ess ( "o contact4 ,9 all ^! cases alike we obta9 a consi/5t action curr5t1 :i* 9 t9 is normally positive1 or t[>ds ! relatively m excit$4 ,,footnotes3 #ad ,foll[+ ano!r l9e ( inquiry ,i obta9$ response to electric /imulus 9 inorganic sub/ances us+ ! me?od ( conductivity v>iation 7see ',de la ,gnralit des ,phnomnes ,molculaires ,produits p> l',electricit sur la ,matire ,inorganique et sur la ,matire ,vivante1' ,travaux du ,congrs ,int]national de ,physique1 ,p>is1 #aijj2 & also ',on ,simil>ities ( ,effect ( ,electric ,/imulus on ,inorganic & ,liv+ ,sub/ances1' ,briti% ,association #aijj4 ,see ,electrician74 ,to br+ out ! p>allelism 9 all details betwe5 ! inorganic & liv+ response1 ,i h 9 ! foll[+ *apt]s us$ ! me?od ( electro-motive v>iation employ$ by physiologi/s4 #ae ,by 't9' is meant an alloy ( t9 & lead us$ z electric fuse4 ,,*apt] ,,xi ,,inorganic ,,response--,,modifi$ ,,app>atus ,,to ,,exhibit ,,response ,,9 ,,metals ,conditions ( obta9+ quantitative measurem5ts--,modification ( ! block me?od--,vibration cell--,application ( /imulus--,graduation ( ! int5sity ( /imulus--,consid]ations %[+ t electric response is due to molecul> di/urbance--,te/ exp]im5t--,molecul> voltaic cell4 ,we h already se5 t metals respond to /imulus by ,e4,m4 v>iation1 j z d animal & vegetable tissues4 ,we h yet to see :e!r ! simil>ity ext5ds to ?is po9t only1 or goes /ill fur!r1 :e!r ! response-curves ( liv+ & 9 organic are alike1 & :e!r ! inorganic response-curve is modifi$1 z liv+ response 0 f\nd to be1 by ! influ5ce ( ext]nal ag5cies4 ,if s1 are ! modifications simil>8 ,:at are ! effects ( sup]position ( /imuli8 ,is !re fatigue8 ,if !re be1 9 :at way does x affect ! curves8 ,& la/ly1 is ! response ( metals exalt$ or depress$ by ! action ( *emical reag5ts8 ,conditions ( obta9+ quantitative measurem5ts4--,9 ord] to c>ry out ^! inve/igations1 x is necess>y to remove all s\rces ( unc]ta9ty1 & obta9 quantitative measurem5ts4 ,_m difficulties at fir/ pres5t$ !mselves 9 ! c\rse ( ?is attempt1 b !y 7 completely remov$ by ! adoption ( ! foll[+ exp]im5tal modification4 ,9 ! simple arrangem5t = qualitative demon/ration ( response 9 metals previ\sly describ$1 successive exp]im5ts w n give results :i* are /rictly comp>able 7#a7 unless ! resi/ance ( ! circuit be ma9ta9$ con/ant4 ,?is w\ld necessitate ! adoption ( "s plan = keep+ ! electrolytic contacts at ,a & ,b absolutely inv>iable4 ,!re %\ld !n be no *ance ( any %ift+ or v>iation ( contact4 7#b7 ,!re mu/ also be "s means ( apply+ successive /imuli ( equal int5sity4 7#c7 ,& = c]ta9 fur!r exp]im5ts x w be necess>y to h "s way ( gradually increas+ or decreas+ ! /imuli 9 a def9ite mann]4 ,modification ( ! block me?od4--,by consid]ation ( ! foll[+ exp]im5tal modifications ( ! block me?od 7fig4#ee71 x w be f\nd easy to con/ruct a p]fect$ =m ( app>atus1 9 :i* all ^! conditions are fully met4 ,! ess5tials to be kept 9 m9d 7 ! introduction ( a complete block midway 9 ! wire1 s t ! di/urbance ( "o half %\ld be prev5t$ f rea*+ ! o!r1 & ! mak+ ( a p]fect electrolytic contact = ! electrodes lead+ to ! galvanomet]4 ,/>t+ f ! simple arrangem5t previ\sly describ$ :]e a /raight wire is clamp$ 9 ! middle 7fig4#ee1 a71 we next arrive at 7b74 ,"h ! wire ,a,b is plac$ 9 a ,u tube & clamp$ 9 ! middle by a tightly fitt+ cork4 ,melt$ p>aff9 wax is p\r$ to a c]ta9 dep? 9 ! b5d ( ! tube4 ,! two limbs ( ! tube are n[ fill$ ) wat]1 till ! ends ,a & ,b are completely imm]s$4 ,connection is made ) ! non-pol>isable electrodes by ! side tubes4 ,vibration may be imp>t$ to ei!r ,a or ,b by means ( ebonite clip hold]s se5 at ! upp] ends ,a,b ( ! wire4 ,illu/ration3 ,,fig4#ee4--,,successive ,,modifications ,,( ,,! ,,block ,,me?od ,,f ,,! ',,/raight ,,wire' 7a7 ,,to ',,cell ,,=m' 7e7 ,:5 ,a is excit$1 curr5t ( response 9 ! wire is f less excit$ ,b to m excit$ ,a4 ,note t ?\gh ! curr5t ( response is con/ant 9 direction1 ! galvanomet] deflection 9 7d7 w be opposite to t 9 7b74 ,x w be se5 t ! two limbs ( ! tube fill$ ) wat] s]ve ! purpose ( ! /rip ( moi/5$ clo? us$ 9 ! la/ exp]im5t to make electric connections ) ! lead+-out electrodes--) ! advantage t we h "h no *ance ( any %ift+ ( contact or v>iation ( surface1 ! contact betwe5 ! wire & ! surr\nd+ liquid be+ p]fect & inv>iable4 ,on n[ vibrat+ ! end ,a ( ! t9 wire by means ( ! ebonite clip hold]1 a curr5t w be f\nd to fl[ f ,b to ,a ?r\gh ! wire--t is to say1 t[>ds ! excit$--& f ,a to ,b 9 ! galvanomet]4 ,! next modification 7c7 is to transf] ! galvanomet] f ! electrolytic to ! metallic "p ( ! circuit1 t is to say1 x is int]pos$ 9 a gap made by cutt+ ! wire ,a,b1 ! upp] "p ( ! circuit be+ directly connect$ by ! electrolyte4 ,vibration ( ,a w n[ give rise to a curr5t ( response :i* fl[s 9 ! metallic "p ( ! circuit ) ! int]pos$ galvanomet] f ,b to ,a4 ,we see t ?\gh ! direction ( ! curr5t 9 ?is is ! same z 9 ! la/ case1 yet ! galvanomet] deflection is n[ rev]s$1 = ! evid5t reason t we h x int]pos$ 9 ! metallic & n 9 ! electrolytic "p ( ! circuit4 ,! next arrangem5t 7d7 consi/s simply ( ! prec$+ plac$ upside d[n4 ,"h ,a & ,b are held p>allel to ea* o!r 9 an electrolytic ba? 7wat]74 ,me*anical vibration may n[ be appli$ to ,a )\t affect+ ,b1 & vice v]sa4 ,! actual app>atus1 ( :i* ?is is a diagrammatic repres5tation1 is se5 9 7e74 ,two pieces1 f ! same specim5 ( wire1 are clamp$ sep>ately at _! l[] ends by means ( ebonite screws1 9 an ,l-%ap$ piece ( ebonite4 ,! wires are fix$ at _! upp] ends to two electrodes--lead+ to ! galvanomet]--& kept mod]ately & uni=mly /ret*$ by spiral spr+s4 ,! h&le1 by :i* a torsional vibration is imp>t$ to ! wire1 may be slipp$ ov] ei!r electrode4 ,! amplitude ( vibration is measur$ by means ( a graduat$ circle4 ,x w be se5 f ^! arrangem5ts3 7#a7 ,t ! cell depict$ 9 7e7 is ess5tially ! same z t 9 7a74 7#b7 ,t ! wires 9 ! cell be+ imm]s$ to a def9ite dep? 9 ! electrolyte !re is always a p]fect & inv>iable contact betwe5 ! wire & ! electrolyte4 ,! difficulty z reg>ds v>iation ( contact is ?us elim9at$4 7#c7 ,t z ! wires ,a & ,b are clamp$ sep>ately bel[1 we may imp>t a sudd5 molecul> di/urbance to ei!r ,a or ,b by giv+ a quick to-&-fro 7torsional7 vibration r\nd ! v]tical wire1 z axis1 by means ( ! h&le4 ,z ! wire ,a is sep>ate f ,b1 di/urbance ( "o w n affect ! o!r4 ,vibration ( ,a produces a curr5t 9 "o direction1 vibration ( ,b 9 ! opposite direction4 ,?us we h means ( v]ify+ e exp]im5t by obta9+ corroborative & rev]s$ effects4 ,:5 ! two wires h be5 br\ght to exactly ! same molecul> condition by ! processes ( anneal+ or /ret*+1 ! effects obta9$ on subject+ ,a or ,b to any giv5 /imulus are always equal 7fig4#ef74 ,illu/ration3 ,,fig4#ef4--;,,equal ,,& ,,opposite ,,responses ,,exhibit$ ,,by ,a ,,& ,b ,usually ,i int]pose an ext]nal resi/ance v>y+ f "o to five megohms accord+ to ! s5sitiv5ess ( ! wire4 ,! resi/ance ( ! electrolyte 9 ! cell is ?us relatively small1 & ! galvanomet] deflections are proportional to ! ,e4,m4 v>iations4 ,x is always advisable to h a high ext]nal resi/ance1 z by ?is means "o is n only able to keep ! deflections )9 ! scale1 b "o is n tr\bl$ by slight accid5tal di/urbances4 ,graduation ( int5sity ( /imulus4--,if n[ a rapid torsional vibration be giv5 to ,a or ,b1 an ,e4,m4 v>iation w be induc$4 ,if ! amplitude ( vibration be kept con/ant1 successive responses--9 sub/ances :i*1 l t91 %[ no fatigue--w be f\nd to be absolutely id5tical4 ,b z '! amplitude ( vibration' is increas$1 response w also become enhanc$ 7see ,*ap4 ,,xv74 ,illu/ration3 ,,fig4#eg4--,,top ,,view ,,( ,,! ,,vibration ,,cell ,! amplitude ( vibration is det]m9$ by means ( movable /ops ,s,s'1 fix$ to ! edge ( ! graduat$ circle ,g4 ,! index arm ,i plays betwe5 ! /ops4 7,! second index arm1 connect$ ) ,b1 & ! second circle are n %[n47 ,amplitude ( vibration is measur$ by means ( ! graduat$ circle 7fig4#eg74 ,a project+ index1 9 connection ) ! vibration-head1 plays betwe5 fix$ & slid+ /ops 7,s & ,s'71 "o at ! z]o po9t ( ! scale1 & ! o!r movable4 ,! amplitude ( a giv5 vibration c ?us be pr$et]m9$ by ! adju/m5t ( ! slid+ /op4 ,9 ?is way we c obta9 ei!r uni=m or def9itely graduat$ /imuli4 ,consid]ations %[+ t electric response is due to molecul> di/urbance4--,! electromotive v>iation v>ies ) ! sub/ance4 ,) sup]position ( /imuli1 a relatively high value is obta9$ 9 t91 am\nt+ sometimes to ne>ly half a volt1 :]eas 9 silv] ! electromotive v>iation is only ab\t #ja ( ?is value4 ,! int5sity ( ! response1 h[ev]1 does n dep5d on ! *emical activity ( ! sub/ance1 = ! electromotive v>iation 9 ! relatively *emically inactive t9 is great] ?an t ( z9c4 ,aga91 ! sign ( response1 positive or negative1 is sometimes modifi$ by ! molecul> condition ( ! wire 7see ,*ap4 ,,xii74 ,z reg>ds ! electrolyte1 dilute ,na,cl solution1 dilute solution ( bi*romate ( pota% c4 are normal 9 _! action1 t is to say1 ! electric response 9 su* electrolytes is practically ! same z ) wat]4 ,ord9>ily ,i use tap-wat] z ! electrolyte4 ,z9c wires 9 ,zn,s,o#d solution give responses simil> 9 "* to ^? giv5 by1 = example1 ,pt or ,sn 9 wat]4 ,te/ exp]im5t4--,x may be urg$ t ! ,e4,m4 effect is due 9 "s way 7#a7 to ! friction ( ! vibrat+ wire aga9/ ! liquid2 or 7#b7 to "s unkn[n surface action1 at ! po9t 9 ! wire ( ! contact ( liquid & air surfaces4 ,?is second objection has already be5 completely met 9 exp]im5tal modification1 fig4#ee1 b1 :]e ! wire 0 %[n to give response :5 kept completely imm]s$ 9 wat]1 v>iation ( surface be+ ?us entirely elim9at$4 ,bo? ^! que/ions may1 h[ev]1 be subject$ to a def9ite & f9al te/4 ,:5 ! wire to be act$ on is clamp$ bel[1 & vibration is imp>t$ to x1 a /rong molecul> di/urbance is produc$4 ,if n[ x be c>efully releas$ f ! clamp1 & ! wire rotat$ backw>ds & =w>ds1 !re c\ld be little molecul> di/urbance1 b ! liquid friction & surface v>iation1 if any1 w\ld rema94 ,! effect ( any slight di/urbance out/&+ ow+ to %ak+ ( ! wire w\ld be relatively v small4 ,we c ?us det]m9e ! effect ( liquid friction & surface action by repeat+ an exp]im5t ) & )\t clamp+4 ,9 a t9 wire cell1 ) int]pos$ ext]nal resi/ance equal to "o million ohms1 ! wire ,a 0 subject$ to a s]ies ( vibrations ?r\gh #ahj1 & a deflection ( #baj;divisions 0 obta9$4 ,a correspond+ negative deflection result$ on vibrat+ ! wire ,b4 ,n[ ,a 0 releas$ f ! clamp1 s t x c\ld be rotat$ backw>ds & =w>ds 9 ! wat] by means ( ! h&le4 ,on vibrat+ ! wire ,a no measurable deflection 0 produc$1 ?us %[+ t nei!r wat] friction nor surface v>iation _h any?+ to d ) ! electric action4 ,! vibration ( ! /ill clamp$ ,b gave rise to ! normal /rong deflection4 ,z all ! re/ ( ! circuit 0 kept absolutely ! same 9 ! two diff]5t sets ( exp]im5ts1 ^! results conclusively prove t ! responsive electro-motive v>iation is solely due to ! molecul> di/urbance produc$ by me*anical vibration 9 ! act$ wire4 ,a new & !oretically int]e/+ molecul> voltaic cell may ?us be made1 9 :i* ! two elem5ts consi/ ( ! same metal4 ,molecul> di/urbance is 9 ?is case ! ma9 s\rce ( en]gy4 ,a cell once made may be kept 9 work+ ord] = "s "t by p\r+ 9 a little vasel9e to prev5t evaporation ( ! liquid4 ,x w be %[n fur!r1 9 succe$+ *apt]s1 by num]\s in/ances1 t any conditions :i* increase molecul> mobility w also increase int5sity ( response1 & conv]sely t any conditions hav+ ! rev]se effect w depress response4 ,,*apt] ,,xii ,,inorganic ,,response--,,me?ods ,,( ,,ensur+ ,,consi/5t ,,results ,prep>ation ( wire--,effect ( s+le /imulus4 ,i %all n[ proce$ to describe 9 detail ! response-curves obta9$ ) metals4 ,! ,e4,m4 v>iations result+ f /imulus range1 z has be5 said1 f #dvolt to #ja ( t value1 accord+ to ! metal employ$4 ,& z ^! are molecul> ph5om5a1 ! effect w also dep5d on ! molecul> condition ( ! wire4 ,prep>ation ( wire4--,9 ord] to h our results ?or\ghly consi/5t1 x is necess>y to br+ ! wire itself into a normal condition = exp]im5t4 ,! v fact ( m\nt+ x 9 ! cell /ra9s x1 & ! aft]-effect ( ?is /ra9 may cause irregul>ities 9 ! response4 ,= ! purpose ( br++ ! wire to ?is normal /ate1 "o or all ( ! foll[+ devices may be us$ ) advantage4 7#a7 ,! wires obta9$ are usually w\nd on spools4 ,x is1 !re=e1 advisable to /raight5 any giv5 l5g?1 be=e m\nt+1 by hold+ x /ret*$1 & rubb+ x up & d[n ) a piece ( clo?4 ,on wa%+ ) wat]1 !y are n[ ready = m\nt+ 9 ! cell4 7#b7 ,! cell is usually fill$ ) tap-wat]1 & a p]iod ( re/ aft] mak+ up1 g5]ally speak+1 improves ! s5sitiv5ess4 ,^! exp$i5ts are ord9>ily suffici5t1 b x occasionally happ5s t ! wire has got into an abnormal condition4 ,illu/ration3 ,,fig4#eh4--;,,effect ,,( ,,anneal+ ,,on ,,increas+ ,,! ,,response ,,( ,,bo? ,a ,,& ,b ,,wires 7,,t97 ,/imuli 7vibration ( #afj7 appli$ at int]vals ( "o m9ute4 ,9 ?is case x w be f\nd helpful 7#c7 to h rec\rse to ! process ( anneal+4 ,= if response be a molecul> ph5om5on1 !n any?+ t increases molecul> mobility w also increase its int5sity4 ,h5ce we may expect anneal+ to enhance responsiv5ess4 ,?is inf]5ce w be se5 v]ifi$ 9 ! record giv5 9 fig4#eh4 ,9 ! case "u consid]ation1 ! conv5i5t me?od employ$ 0 by p\r+ hot wat] into ! cell1 & all[+ x to /& & cool sl[ly4 ,! fir/ ?ree pairs ( responses 7 tak5 by /imulat+ ,a & ,b alt]nately1 on m\nt+ 9 ! cell1 :i* 0 fill$ ) wat]4 ,hot wat] 0 !n sub/itut$1 & ! cell 0 all[$ to cool d[n to its orig9al temp]ature4 ,! six foll[+ pairs ( responses 7 !n tak54 ,t ?is b5eficial effect ( anneal+ 0 n due to any accid5tal circum/ance w be se5 f ! fact t bo? wires h _! s5sitiv5ess equally enhanc$4 7#d7 ,9 addition to ?is mode ( anneal+1 bo? wires may be %ort-circuit$ & vibrat$ = a "t4 ,la/ly 7#e7 slight /ret*+ 9 situ w also sometimes be f\nd b5eficial4 ,= ?is purpose ,i h a screw arrangem5t4 ,by "o or all ( ^! me?ods1 ) a little practice1 x is always possible to br+ ! wires to a normal condition4 ,! responses subsequ5tly obta9$ become extraord9>ily consi/5t4 ,!re is !re=e no reason :y p]fect results %\ld n be arriv$ at4 ,illu/ration3 ,,fig4#ei4--,,uni=m ,,responses ,,9 ,,t9 ,effect ( s+le /imulus4--,! accompany+ figure 7fig4#ei7 gives a s]ies1 ea* ( :i* is ! response curve = a s+le /imulus ( uni=m int5sity1 ! amplitude ( vibration be+ kept con/ant4 ,! p]fect regul>ity ( responses w be notic$ 9 ?is figure4 ,! wire aft] a long p]iod ( re/ may be 9 an abnormal condition1 b aft] a %ort p]iod ( /imulation ! responses become extremely regul>1 z may be notic$ 9 ?is figure4 ,t9 is1 usually speak+1 almo/ indefatigable1 & ,i h (t5 obta9$ sev]al hundr$s ( successive responses %[+ practically no fatigue4 ,9 ! figure x w be notic$ t ! ris+ portion ( ! curve is some:at /eep1 & ! recov]y convex to ! abscissa1 ! fall be+ relatively rapid 9 its fir/1 & less rapid 9 its lat]1 p>ts4 ,z ! electric v>iation is ! concomitant effect ( molecul> di/urbance--a tempor>y upset ( ! molecul> equilibrium--on ! cessation ( ! ext]nal /imulus1 ! excitatory /ate1 & its expression 9 electric v>iation1 disappe> ) ! return ( ! molecules to _! condition ( equilibrium4 ,?is process is se5 cle>ly 9 ! curve ( recov]y4 ,diff]5t metals exhibit diff]5t p]iods ( recov]y1 & ?is aga9 is modifi$ by any influ5ce :i* affects ! molecul> condition4 ,t ! excitatory /ate p]si/s = a "t ev5 on ! cessation ( /imulus c be indep5d5tly %[n by keep+ ! galvanomet] circuit op5 dur+ ! application ( /imulus1 & complet+ x at v>i\s %ort int]vals aft] ! cessation1 :5 a p]si/+ electrical effect1 dim9i%+ rapidly ) "t1 w be app>5t4 ,! rate ( recov]y imm$iately on ! cessation ( /imulus is r rapid1 b traces ( /ra9 p]si/ = a %ort "t4 ,,*apt] ,,xiii ,,inorganic ,,response--,,molecul> ,,mobility3 ,,its ,,influ5ce ,,on ,,response ,effects ( molecul> in]tia--,prolongation ( p]iod ( recov]y by ov]/ra9--,molecul> model--,r$uction ( molecul> sluggi%ness att5d$ by quick5$ recov]y & height5$ response--,effect ( temp]ature--,modification ( lat5t p]iod & p]iod ( recov]y by ! action ( *emical reag5ts--,diphasic v>iation4 ,we h se5 t ! /imulation ( matt] causes an electric v>iation1 & t ! act$ sub/ance gradually recov]s f ! effect ( /imulus4 ,we %all next /udy h[ ! =m ( response-curves is modifi$ by v>i\s ag5cies4 ,9 ord] to /udy ^! effects we mu/ use1 9 practice1 a highly s5sitive galvanomet] z ! record] ( ,e4,m4 v>iations4 ,?is necessitates ! use ( an in/rum5t ) a comp>atively long p]iod ( sw+ ( ne$le1 or ( susp5d$ coil 7z 9 a ,d',arsonval74 ,ow+ to in]tia ( ! record+ galvanomet]1 h[ev]1 !re is a lag produc$ 9 ! records ( ,e4,m4 *anges4 ,b ?is c be di/+ui%$ f ! effect ( ! molecul> in]tia ( ! sub/ance itself by comp>+ two successive records tak5 ) ! same in/rum5t1 9 "o ( :i* ! latt] effect is relatively abs5t1 & 9 ! o!r pres5t4 ,we wi%1 = example1 to f9d out :e!r ! ,e4,m4 effect ( me*anical /imulus is in/antane\s1 or1 aga91 :e!r ! effect disappe>s imm$iately4 ,we fir/ take a galvanomet] record ( ! sudd5 introduction & cessation ( an ,e4,m4,f4 on ! circuit conta9+ ! vibration-cell 7fig4#fj1 a74 ,we !n take a record ( ! ,e4,m4 effect produc$ by a /imulus caus$ by a s+le torsional vibration4 ,9 ord] to make ! conditions ( ! two exp]im5ts z simil> z possible1 ! di/urb+ ,e4,m4,f41 f a pot5tiomet]1 is previ\sly adju/$ to give a deflection ne>ly equal to t caus$ by /imulus4 ,! torsional vibration 0 accompli%$ 9 a qu>t] ( a second1 & ! contact ) ! pot5tiomet] circuit 0 also made = ! same l5g? ( "t4 ,illu/ration3 ,,fig4#fj 7a7 ,arrangem5t = apply+ a %ort-liv$ ,e4,m4,f4 7b7 ,diff]5ce 9 ! p]iods ( recov]y3 7#a7 f in/antane\s ,e4,m4,f42 & 7#b7 t caus$ by me*anical /imulus4 ,! record 0 !n tak5 z foll[s4 ,! record+ drum _h a fa/ spe$ ( six in*es 9 a m9ute1 "o ( ! small subdivisions repres5t+ a second4 ,! batt]y contact 9 ! ma9 pot5tiomet] circuit 0 made = a qu>t] ( a second z j m5tion$ & a record tak5 ( ! effect ( a %ort-liv$ ,e4,m4,f4 on ! circuit conta9+ ! cell4 7#b7 ,a record 0 next tak5 ( ! ,e4,m4 v>iation produc$ 9 ! cell by a s+le /imulus4 ,x w be se5 on comp>ison ( ! two records t ! maximum effect took place relatively lat] 9 ! case ( me*anical /imulus1 & t :]eas ! galvanomet] recov]y 9 ! =m] case took place 9 #aaseconds1 ! recov]y 9 ! latt] 0 n complete till aft] #fjseconds 7fig4#fj1 b74 ,?is %[s t x takes "s "t = ! effect ( /imulus to atta9 its maximum1 & t ! effect does n disappe> till aft] ! lapse ( a c]ta9 int]val4 ,! "t ( recov]y f /ra9 dep5ds on ! int5sity ( /imulus4 ,x takes a long] "t to recov] f a /rong] /imulus4 ,b1 o!r ?+s be+ equal1 successive recov]y p]iods f successive /imulations ( equal int5sity are1 g5]ally speak+1 ! same4 ,we may n[ /udy ! influ5ce ( any *ange 9 ext]nal conditions by obs]v+ ! modifications x produces 9 ! normal curve4 ,illu/ration3 ,,fig4#fa4--,,prolongation ,,( ,,p]iod ,,( ,,recov]y ,,aft] ,,ov]/ra9 ,recov]y is complete 9 #fj :5 ! /imulus is due to #bj vibration4 ,b ) /rong] /imulus ( #dj vibration1 ! p]iod ( recov]y is prolong$ to #ij4 ,prolongation ( p]iod ( recov]y by ov]/ra94--,! pair ( records giv5 9 fig4#fa %[s h[ recov]y is delay$1 z ! effect ( ov]/ra94 ,curve 7a7 is = a s+le /imulus due to a vibration ( amplitude #bj1 & curve 7b7 = a /imulus ( #dj amplitude ( vibration4 ,x w be notic$ h[ relatively prolong$ is ! recov]y 9 ! latt] case4 ,illu/ration3 ,,fig4#fb4--,,model ,,%[+ ,,! ,,effect ,,( ,,friction ,molecul> ,model4--,we h se5 t ! electric response is an outw>d expression ( ! molecul> di/urbance produc$ by ! action ( ! /imulus4 ,! ris+ "p ( ! response-curve ?us exhibits ! effect ( molecul> upset1 & ! fall+ "p1 or recov]y1 ! re/oration to equilibrium4 ,! me*anical model 7fig4#fb7 w help u to visualise _m complex response ph5om5a4 ,! molecul> model consi/s ( a torsional p5dulum--a wire ) a dep5d5t sph]e4 ,by ! /imulus ( a bl[ !re is produc$ a torsional vibration--a response foll[$ by recov]y4 ,! writ+ lev] atta*$ to ! p5dulum records ! response-curves4 ,! =m ( ^! curves1 /imulus rema9+ con/ant1 w be modifi$ by friction2 ! less ! friction1 ! great] is ! mobility4 ,! friction may be v>i$ by m or less rais+ a vessel ( s& t\*+ ! p5dulum4 ,by v>y+ ! friction ! foll[+ curves 7 obta9$4 7a7 ,:5 !re is little friction we get an aft]-oscillation1 to :i* we h ! correspond+ ph5om5on 9 ! ret9al aft]-oscillation 7comp>e fig4#aje74 7b & c7 ,if ! friction is increas$1 !re is a damp+ ( oscillation4 ,9 7c7 we get recov]y-curves simil> to ^? f\nd 9 n]ve1 muscle1 plant1 & metal4 7d7 ,if ! friction is /ill fur!r increas$ ! maximum is rea*$ mu* lat]1 z w be se5 9 ! increas+ slant ( ! ris+ "p ( ! curve2 ! height ( response is dim9i%$ & ! p]iod ( recov]y v mu* prolong$ by p>tial molecul> arre/4 ,! curve 7d7 is v simil> to ! 'molecul> arre/' curve obta9$ by small dose ( *emical reag5ts :i* act z 'poison' on liv+ tissue or on metals 7comp>e fig4#ic1 a74 7e7 ,:5 ! molecul> mobility is fur!r decreas$ !re is no recov]y 7comp>e fig4#ic1 b74 ,/ill fur!r increase ( friction completely arre/s ! molecul> p5dulum1 & !re is no response4 ,f :at has be5 said1 x w be se5 t if 9 any way ! friction is dim9i%$ or mobility increas$ ! response w be enhanc$4 ,?is is well exemplifi$ 9 ! height5$ response aft] anneal+ 7fig4#eh7 & aft] prelim9>y vibration 7figs4 #ha1 #hb74 ,possibly connect$ ) ?is may be ! increas$ responses exhibit$ by ! action ( /imulants 7figs4 #hi1 #ij74 ,r$uction ( molecul> sluggi%ness att5d$ 7#a7 by quick5$ recov]y4--,sometimes1 aft] a cell has be5 re/+ = too long a p]iod1 especially on cold days1 ! wire gets into a sluggi% condition1 & ! p]iod ( recov]y is !reby prolong$4 ,b successive vibrations gradually remove ?is in]tness1 & recov]y is !n ha/5$4 ,?is is %[n 9 ! accompany+ curves1 fig4#fc1 :]e 7a7 exhibits only v p>tial recov]y ev5 aft] ! expiration ( #fjseconds1 :]eas :5 a few vibrations _h be5 giv5 recov]y 0 entirely complet$ 9 #dgseconds 7b74 ,!re 0 "h little *ange 9 ! height ( response4 ,illu/ration3 ,,fig4#fc 7a7 ,sl[ recov]y ( a wire 9 a sluggi% condition4 7b7 ,quick5$ recov]y 9 ! same wire aft] a few vibrations4 ,or 7#b7 by height5$ response4--,! removal ( sluggi%ness by vibration1 result+ 9 increas$ molecul> mobility1 is 9 o!r in/ances att5d$ by increase 9 ! height ( response1 z w be se5 f ! two sets ( records :i* foll[ 7fig4#fd74 ,cold1 due to prevail+ fro/y wea!r1 _h made ! wires 9 ! cell some:at le?>gic4 ,! records 9 7a7 7 ! fir/ tak5 on ! day ( ! exp]im5t4 ,! amplitudes ( vibration 7 #de1 #ij1 & #ace4 ,9 7b7 are giv5 ! records ( ! next s]ies1 :i* are 9 e case great] ?an ^? ( 7a74 ,?is %[s t previ\s vibration1 by conf]r+ increas$ mobility1 _h height5$ ! response4 ,9 ?is case1 removal ( molecul> sluggi%ness is att5d$ by great] int5sity ( response1 )\t mu* *ange 9 ! p]iod ( recov]y4 ,9 connection ) ?is x mu/ be rememb]$ t great] /ra9 consequ5t on height5$ response has a g5]al t5d5cy to a prolongation ( ! p]iod ( recov]y4 ,illu/ration3 ,,fig4#fd 7a7 ,?ree sets ( responses = #de1 #ij1 & #ace vibration 9 a sluggi% wire4 7b7 ,! next ?ree sets ( responses 9 ! same wire2 increas$ mobility conf]r$ by previ\s vibration has height5$ ! response4 ,x is ?us se5 t :5 ! wire is 9 a sluggi% condition1 successive vibrations conf] increas$ molecul> mobility1 :i* f9ds expression 9 quick5$ recov]y or height5$ response4 ,effect ( temp]ature4--,simil> consid]ations lead u to expect t a mod]ate rise ( temp]ature w be conducive to increase ( response4 ,?is is exhibit$ 9 ! next s]ies ( records4 ,! wire at ! l[ temp]ature ( #e;,c4 happ5$ to be 9 a sluggi% condition1 & ! responses to vibrations ( #de to #ij 9 amplitude 7 feeble4 ,tepid wat] at #cj;,c4 0 n[ sub/itut$ = ! cold wat] 9 ! cell1 & ! responses und]w5t a rem>kable enhancem5t4 ,b ! excessive molecul> di/urbance caus$ by ! high temp]ature ( #ij;,c4 produc$ a great dim9ution ( response 7fig4#fe74 ,illu/ration3 ,,fig4#fe4--,,responses ,,( ,a ,,wire ,,to ,,amplitudes ,,( ,,vibration #de ,,& #ij 7a7 ,responses :5 ! wire 0 9 a sluggi% condition at temp]ature ( #e;,c4 7b7 ,enhanc$ response at #cj;,c4 7c7 ,dim9ution ( response at #ij;,c4 ,diphasic v>iation4--,x has already be5 said t if two po9ts ,a & ,b are 9 ! same physico-*emical condition1 !n a giv5 /imulus w give rise to simil> excitatory electric effects at ! two po9ts4 ,if ! galvanomet] deflection is 'up' :5 ,a alone is excit$1 ! excitation ( ,b w give rise to a d[nw>d deflection4 ,:5 ! two po9ts are simultane\sly excit$ ! electric v>iation at ! two po9ts w cont9u\sly balance ea* o!r4 ,"u su* conditions !re w be no resultant deflection4 ,b if ! int5sity ( /imulation ( "o po9t is relatively /rong]1 !n ! balance w be di/urb$1 & a resultant deflection produc$ ^: sign & magnitude c be f\nd indep5d5tly by ! algebraical summation ( ! individual effects ( ,a & ,b4 ,x has also be5 %[n t a balanc+ po9t = ! block1 :i* is approximately ne> ! middle ( ! wire1 may be f\nd s t ! vibrations ( ,a & ,b ?r\gh ! same amplitude produce equal & opposite deflection4 ,simultane\s vibration ( bo? w give no resultant curr5t2 :5 ! block is aboli%$ & ! wire is vibrat$ z a :ole1 !re w /ill be no resultant1 inasmu* z simil> excitations are produc$ at ,a & ,b4 ,aft] obta9+ ! balance1 if we apply an excit+ reag5t l ,na#b;,,co#c at "o po9t1 & a depress+ reag5t l ,k,br at ! o!r1 ! responses w n[ become unequal1 ! m excitable po9t giv+ a /rong] deflection4 ,we c1 h[ev]1 make ! two deflections equal by increas+ ! amplitude ( vibration ( ! less s5sitive po9t4 ,! two deflections may ?us be r5d]$ equal & opposite1 b ! "t relations--! lat5t p]iod1 ! "t rate = atta9+ ! maximum excitation & recov]y f t effect--w no long] be ! same 9 ! two cases4 ,!re w\ld !re=e be no cont9u\s balance1 & we obta9 in/ead a v int]e/+ diphasic record4 ,i give bel[ an exact reproduction ( ! response-curves ( ,a & ,b record$ on a fa/-mov+ drum4 ,x w be rememb]$ t "o po9t 0 t\*$ ) ,na#b;,,co#c & ! o!r ) ,k,br4 ,by suitably increas+ ! amplitude ( vibration ( ! less s5sitive1 ! two deflections 7 r5d]$ approximately equal4 ,! records ( ,a & ,b 7 at fir/ tak5 sep>ately 7fig4#ff1 a74 ,x w be notic$ t ! maximum deflection ( ,a 0 atta9$ relatively mu* e>li] ?an t ( ,b4 ,! resultant curve ,r' 0 obta9$ by summation4 ,illu/ration3 ,,fig4#ff4--;,,diphasic ,,v>iation 7a7 ,records ( ,a & ,b obta9$ sep>ately4 ,r' is ! resultant by algebraical summation4 7b7 ,diphasic record obta9$ by simultane\s /imulation ( ,a & ,b4 ,aft] tak+ ! records ( ,a & ,b sep>ately1 a record ( resultant effect ,r due to simultane\s vibration ( ,a & ,b 0 next tak54 ,x gave ! curi\s two-phas$ response--positive effect foll[$ by negative aft]-vibration1 practically simil> to ! resultant curve ,r' 7fig4#ff1 b74 ,! positive portion ( ! curve is due to ,a effect & ! negative to ,b4 ,if by any means1 say by ei!r increas+ ! amplitude ( vibration ( ,a or increas+ its s5sitiv5ess1 ! response ( ,a is v greatly enhanc$1 !n ! positive effect w\ld be pr$om9ant & ! negative effect w\ld become inconspicu\s4 ,:5 ! two con/itu5t responses are ( ! same ord] ( magnitude1 we %all h a positive response foll[$ by a negative aft]-vibration2 ! fir/ twit* w belong to ! "o :i* responds e>li]4 ,if ! response ( ,a is v mu* r$uc$1 !n ! positive effect w be r$uc$ to a m]e twit* & ! negative effect w become pr$om9ant4 ,i give a s]ies ( records1 fig4#fg1 9 :i* ^! ?ree pr9cipal types are well exhibit$1 ! two contacts hav+ be5 r5d]$ unequally excitable by solutions ( ! two reag5ts ,k,br & ,na#b;,,co#c4 ,a & ,b 7 vibrat$ simultane\sly & records tak54 7a7 ,fir/1 ! relative response ( ,b 7d[nw>d7 is increas$ by increas+ its amplitude ( vibration4 ,! amplitude ( vibration ( ,a 0 ?r\gh\t ma9ta9$ con/ant4 ,! negative or d[nw>d response is n[ v conspicu\s1 !re be+ only a m]e prelim9>y indication ( ! positive effect4 7b7 ,! amplitude ( vibration ( ,b is n[ slightly r$uc$1 & we obta9 ! diphasic effect4 7c7 ,! int5sity ( vibration ( ,b is dim9i%$ /ill fur!r1 & ! negative effect is se5 r$uc$ to a slight d[nw>d aft]-vibration1 ! positive up-curve be+ n[ v prom95t 7fig4#fg74 ,illu/ration3 ,,fig4#fg4--,,negative1 ,,diphasic1 ,,& ,,positive ,,resultant ,,response ,cont9u\s trans=mation f negative to positive4--,i h %[n ! ?ree phases ( trans=mation1 ! int5sity ( "o ( ! con/itu5t responses be+ v>i$ by alt]+ ! int5sity ( di/urbance4 ,9 ! foll[+ record 7fig4#fh7 ,i succe$$ 9 obta9+ a cont9u\s trans=mation f positive to negative phase by a cont9u\s *ange 9 ! relative s5sitiv5ess ( ! two contacts4 ,i f\nd t traces ( aft]-effect due to ! application ( ,na#b;,,co#c rema9 = a "t4 ,if ! reag5t is previ\sly appli$ to an area & ! traces ( ! c>bonate !n wa%$ (f1 ! increas$ s5sitiv5ess conf]r$ disappe>s gradually4 ,aga91 if we apply ,na#b;,,co#c solution to a fre% po9t1 ! s5sitiv5ess gradually increases4 ,!re is ano!r fur!r int]e/+ po9t to be notic$3 ! beg9n+ ( response is e>li] :5 ! application ( ,na#b;,,co#c is fre%4 ,illu/ration3 ,,fig4#fh4--;,,cont9u\s ,,trans=mation ,,f ,,negative ,,to ,,positive ,,?r\gh ,,int]m$iate ,,diphasic ,,response ,?ick dots repres5t ! times ( application ( successive /imuli4 ,we h ?us a wire held at "o end1 & successive uni=m vibrations at int]vals ( "o m9ute imp>t$ to ! wire z a :ole1 by means ( a vibration head on ! o!r end4 ,ow+ to ! aft]-effect ( previ\s application ( ,na#b;,,co#c ! s5sitiv5ess ( ,b is at ! beg9n+ great1 h5ce ! ?ree resultant responses at ! beg9n+ are negative or d[nw>d4 ,dilute solution ( ,na#b;,,co#c is next appli$ to ,a4 ,! response ( ,a 7up7 beg9s e>li] & cont9ues to gr[ /rong] & /rong]4 ,h5ce1 aft] ?is application1 ! response %[s a prelim9>y positive twit* ( ,a foll[$ by negative deflection ( ,b4 ,! positive gr[s cont9u\sly4 ,at ! fif? response ! two phases1 positive & negative1 become equal1 aft] t ! positive becomes v prom95t1 ! negative be+ r$uc$ z a feeble aft]-vibration4 ,x ne$ only be add$ "h t ! diphasic v>iations z exhibit$ by metals are 9 e way c\nt]p>ts ( simil> ph5om5a obs]v$ 9 animal tissues4 ,,*apt] ,,xiv ,,inorganic ,,response--,,fatigue1 ,,/aircase1 ,,& ,,modifi$ ,,response ,fatigue 9 metals--,fatigue "u cont9u\s /imulation--,/aircase effect--,rev]s$ responses due to molecul> modification 9 n]ve & metal1 & _! trans=mation into normal aft] cont9u\s /imulation--,increas$ response aft] cont9u\s /imulation4 ,illu/ration3 ,,fig4#fi4--;,,fatigue ,,9 ,,muscle 7,,wall]7 ,illu/ration3 ,,fig4#gj4--;,,fatigue ,,9 ,,plat9um ,fatigue4--,9 "s metals1 z 9 muscle & 9 plant1 we f9d in/ances ( t progressive dim9ution ( response :i* is kn[n z fatigue 7fig4#fi74 ,! accompany+ record %[s ?is 9 plat9um 7fig4#gj74 ,x has be5 said t t9 is practically indefatigable4 ,we mu/1 h[ev]1 rememb] t ?is is a "q ( degree only4 ,no?+ is absolutely indefatigable4 ,! exhibition ( fatigue dep5ds on v>i\s conditions4 ,ev5 9 t91 !n1 ,i obta9$ ! *>act]i/ic fatigue-curve ) a specim5 :i* _h be5 9 cont9u\s use = _m days 7fig4#ga74 ,:ile discuss+ ! subject ( fatigue 9 plants1 ,i h adduc$ consid]ations :i* %[$ t ! residual effect ( /ra9 0 "o ( ! ma9 causes = ! production ( fatigue4 ,?is conclusion receives indep5d5t support f ! records obta9$ ) metals4 ,illu/ration3 ,,fig4#ga4--;,,fatigue ,,%[n ,,by ,,t9 ,,wire ,,:i* ,,_h ,,be5 ,,cont9u\sly ,,/imulat$ ,,= ,,sev]al ,,days ,9 ?is connection ! important fact is t ! v>i\s typical fatigue effects exhibit$ 9 liv+ sub/ances are exactly reproduc$ 9 metals1 :]e !re c be "q nei!r ( fatigue-product produc+ fatigue effects1 nor ( ^? con/ructive processes by :i* !y might be remov$4 ,we h se51 bo? 9 muscles & 9 plants1 t if suffici5t "t = complete recov]y be all[$ betwe5 ea* pair ( /imuli1 ! heights ( successive responses are ! same1 & !re is no app>5t fatigue 7see page#ci74 ,b ! height ( response dim9i%es z ! excitation int]val is %ort5$4 ,we f9d ! same ?+ 9 metals4 ,bel[ is giv5 a record tak5 ) t9 7fig4#gb74 ,?r\gh\t ! exp]im5t ! amplitude ( vibration 0 ma9ta9$ con/ant1 b 9 7a7 ! int]val betwe5 consecutive /imuli 0 #a'1 :ile 9 7b7 ?is 0 r$uc$ to #cj4 ,a dim9ution ( height imm$iately occurs4 ,on re/or+ ! orig9al rhy?m z 9 7c71 ! responses rev]t to _! fir/ l>ge value4 ,?us we see t :5 ! wire has n completely recov]$1 its responses1 ow+ to residual /ra91 und]go dim9ution4 ,height ( response is ?us decreas$ by incomplete recov]y4 ,if !n suffici5t "t be n all[$ = p]fect recov]y1 we c und]/& h[1 "u c]ta9 circum/ances1 ! residual /ra9 w\ld progressively increase ) repetition ( /imulus1 & ?us !re w\ld be a progressive dim9ution ( height ( response or fatigue4 ,aga91 we saw 9 ! la/ *apt] t increase ( /ra9 necessitates a long] p]iod ( recov]y4 ,?us ! long] a wire is /imulat$1 ! m & m ov]/ra9$ x becomes1 & x !re=e requires a gradual prolongation ( ! int]val betwe5 ! successive /imuli1 if recov]y is to be complete4 ,?is int]val1 h[ev]1 be+ ma9ta9$ con/ant1 ! recov]y p]iods virtually und]go a gradual r$uction1 & successive recov]ies become m & m incomplete4 ,^! consid]ations may be f\nd to af=d an insight into ! progressive dim9ution ( response 9 fatigu$ sub/ances4 ,illu/ration3 ,,fig4#gb4--;,,dim9ution ,,( ,,response ,,due ,,to ,,%ort5+ ,,! ,,p]iod ,,( ,,recov]y ,! /imulus is ma9ta9$ con/ant4 ,9 7a7 ! int]val betwe5 two successive /imuli is "o m9ute1 9 7b7 x is half a m9ute1 & 9 7c7 x is aga9 "o m9ute4 ,! response 9 7b7 is feebl] ?an 9 ei!r 7a7 or 7c74 ,fatigue "u cont9u\s /imulation4--,fatigue is p]haps be/ %[n "u cont9u\s /imulation4 ,= example1 9 muscles1 :5 fre% & n fatigu$1 ! top ( ! tetanic curve is horizontal1 or may ev5 be asc5d+1 b ) long-cont9u$ /imulation ! curve decl9es4 ,! rapidity ( ?is decl9e dep5ds on ! nature ( ! muscle & its previ\s condition4 ,9 metals ,i h f\nd exactly p>allel in/ances4 ,9 t91 s little liable to fatigue1 ! top ( ! curve is horizontal or asc5d+2 or x may exhibit a slight decl9e4 ,b ! record ) plat9um %[s ! rapid decl9e due to fatigue 7fig4#gc74 ,illu/ration3 ,,fig4#gc 7a7 ,! top ( response-curve "u cont9u\s /imulation 9 t9 is horizontal or asc5d+ z 9 figure4 7b7 ,9 plat9um !re is rapid decl9e ow+ to fatigue4 ,tak+ any ( ^! in/ances1 say t 9 :i* fatigue is mo/ prom95t1 x is f\nd t %ort p]iod ( re/ re/ores ! orig9al int5sity ( response4 ,?is af=ds additional pro( ( ! fact t fatigue is due to ov]/ra91 & t ?is /ra91 ) its sign ( att5dant fatigue1 disappe>s ) "t4 ,/aircase effect4--,we %all n[ discuss an effect :i* appe>s to be ! direct opposite ( fatigue4 ,?is is ! curi\s ph5om5on kn[n to physiologi/s z '! /aircase' effect1 9 :i* successive uni=m /imuli produce a s]ies ( increas+ responses4 ,?is is se5 "u p>ticul> conditions 9 ! response ( c]ta9 muscles 7fig4#gd1 a74 ,x is also obs]v$ sometimes ev5 9 n]ve1 :i* o!rwise1 g5]ally speak+1 gives uni=m responses4 ,( ?is effect1 no satisfactory !ory has z yet be5 (f]$4 ,x is 9 direct contradiction to t !ory :i* supposes t ea* /imulus is foll[$ by dissimilation or break-d[n ( ! tissue1 r$uc+ its function bel[ p>4 ,= 9 ^! cases ! suppos$ dissimilation is foll[$ n by a decrease b by an increase ( functional activity4 ,?is '/aircase effect' ,i h %[n to be occasionally exhibit$ by plants4 ,i h also f\nd x 9 metals4 ,9 ! la/ *apt] we h se5 t a wire (t5 falls1 especially aft] re/+ = a long "t1 into a /ate ( comp>ative sluggi%ness1 & t ?is molecul> in]tness !n gradually gives place to increas$ mobility "u /imulation4 ,z a consequ5ce1 an increas$ response is ?us obta9$4 ,i give 9 fig4#gd1 b1 a s]ies ( responses to uni=m /imuli1 exhibit$ by plat9um :i* _h be5 at re/ = "s "t4 ,?is effect is v cle>ly %[n "h4 ,s we see t 9 a sub/ance :i* has previ\sly be5 9 a sluggi% condition1 /imulation conf]s increas$ mobility4 ,response ?us rea*es a maximum1 b cont9u$ /imulation may aft]w>ds produce ov]/ra91 & ! subsequ5t responses may !n %[ a decl9e4 ,?is consid]ation w expla9 c]ta9 types ( responses exhibit$ by muscles1 :]e ! fir/ "p ( ! s]ies exhibits a /aircase increase foll[$ by decl9+ responses ( fatigue4 ,illu/ration3 ,,fig4#gd4--',,/aircase' ,,effect 7a7 9 muscle 7aft] ,engelmann74 7b7 9 metal4 ,rev]s$ response due to molecul> modification & its trans=mation into normal aft] cont9u\s /imulation 7#a7 9 n]ve4--,ref]5ce has already be5 made to ! fact t a n]ve :i*1 :5 fre%1 exhibit$ ! normal negative response1 w (t51 if kept = "s "t 9 pres]vative sal9e1 und]go a molecul> modification1 aft] :i* x gives a positive v>iation4 ,?us :ile ! response giv5 by fre% n]ve is normal or negative1 a /ale n]ve gives modifi$1 i4e4 rev]s$ or positive1 response4 ,?is peculi> modification does n always occur1 yet is too frequ5t to be consid]$ abnormal4 ,aga91 :5 su* a n]ve is subject$ to tetanisation or cont9u\s /imulation1 ?is modifi$ response t5ds once m to become normal4 ,x is f\nd t n only tetanisation1 b also ,,co#b has ! p[] ( conv]t+ ! modifi$ response into normal4 ,h5ce x has be5 sugge/$ t ! conv]sion "u tetanisation ( modifi$ response to normal1 9 /ale n]ve1 is due to a hypo!tical evolution ( ,,co#b 9 ! n]ve dur+ /imulation4#af 7#b7 ,9 metals4--,i h1 h[ev]1 met ) exactly p>allel ph5om5a 9 metals1 :]e1 ow+ to "s molecul> modification1 ! responses became rev]s$1 & :]e1 "u cont9u\s /imulation1 ?\gh "h !re c\ld be no possibility ( ! evolution ( ,,co#b1 !y t5d$ aga9 to become normal4 ,if aft] m\nt+ a wire 9 a cell fill$ ) wat]1 x be set aside = too long a "t1 ,i h sometimes notic$ t x und]goes a c]ta9 modification1 ow+ to :i* its response ceases to be normal & becomes rev]s$ 9 sign4 ,i h obta9$ ?is effect ) v>i\s metals1 = in/ance lead & t91 & ev5 ) ! *emically inactive sub/ance--plat9um4 ,illu/ration3 ,,fig4#ge4--;,,abnormal ,,positive 7,,up7 ,,response ,,9 ,,n]ve ,,conv]t$ ,,into ,,normal 7,,d[n7 ,,response ,,aft] ,,cont9u\s ,,/imulation ,t 7,,wall]7 ,! galvanomet] is n dead-beat1 & %[s aft]-oscillation4 ,! subject w be made cle>] if we fir/ foll[ 9 detail ! ph5om5on exhibit$ by modifi$ n]ve1 giv+ ?is abnormal response4 ,! normal responses 9 n]ve are usually repres5t$ by 'd[n' & ! rev]s$ abnormal responses by 'up' curves4 ,9 ! modifi$ n]ve1 !n1 ! abnormal responses are 'up' in/ead ( ! normal 'd[n4' ,! record ( su* abnormal response 9 ! modifi$ n]ve is %[n 9 fig4#ge4 ,x w be notic$ t 9 ?is1 ! successive responses are und]go+ a dim9ution1 or t5d+ t[>ds ! normal4 ,aft] cont9u\s /imulation or tetanisation 7,t71 x w be se5 t ! abnormal or 'up' responses are conv]t$ into normal or 'd[n4' ,i %all n[ give a record :i* w exhibit an exactly simil> trans=mation f ! abnormal to normal response aft] cont9u\s /imulation4 ,"h ! normal responses are repres5t$ by 'up' & ! abnormal by 'd[n' curves4 ,?is record 0 giv5 by a t9 wire1 :i* _h be5 molecul>ly modifi$ 7fig4#gf74 ,we h at fir/ ! abnormal responses2 successive responses are und]go+ a dim9ution or t5d+ t[>ds ! normal2 aft] cont9u\s /imulation 7,t71 ! subsequ5t responses are se5 to h become normal4 ,ano!r record1 obta9$ ) plat9um1 %[s ! same ph5om5on 7fig4#gg74 ,illu/ration3 ,,fig4#gf ,,& ,,fig4#gg ,abnormal 'd[n' response 9 t9 7fig4#gf7 & 9 plat9um 7fig4#gg7 trans=m$ into normal 'up' response1 aft] cont9u\s /imulation1 ,t4 ,on plac+ ! ?ree sets ( records--n]ve1 t91 & plat9um--side by side1 x w be se5 h[ ess5tially simil> !y are 9 e respect4#ag ,?is rev]sion to normal is se5 to h appe>$ 9 a pron\nc$ mann] aft] rapidly cont9u\s /imulation1 9 process ( :i* ! modifi$ molecul> condition mu/ 9 "s way h rev]t$ to ! normal4 ,illu/ration3 ,,fig4#gh4--,,! ,,gradual ,,transition ,,f ,,abnormal ,,to ,,normal ,,response ,,9 ,,plat9um ,! transition w be se5 to h comm5c$ at ! ?ird & end$ at ! sev5?1 c\nt+ f ! left4 ,be+ desir\s to trace ?is *ange gradually tak+ place1 ,i took a plat9um wire cell giv+ modifi$ responses1 & obta9$ a s]ies ( records ( effects ( individual /imuli cont9u$ = a long "t4 ,9 ?is s]ies1 ! po9ts ( transition f modifi$ response to normal w be cle>ly se5 7fig4#gh74 ,illu/ration3 ,,fig4#gi4--,,! ,,normal ,,response a ,,9 ,,n]ve ,,enhanc$ ,,to b ,,aft] ,,cont9u\s ,,/imulation ,t 7,,wall]7 ,! normal response 9 n]ve is record$ 'd[n4' ,illu/ration3 ,,fig4#hj4--;,,enhanc$ ,,response ,,9 ,,plat9um ,,aft] ,,cont9u\s ,,/imulation ,t ,increas$ response aft] cont9u\s /imulation4--,we h se5 t responses to uni=m /imuli sometimes %[ a /aircase increase1 app>5tly ow+ to ! gradual removal ( molecul> sluggi%ness4 ,possibly analog\s to ?is is ! increase ( response 9 n]ve aft] cont9u\s /imulation or tetanisation1 obs]v$ by ,wall] 7fig4#gi74 ,l ! /aircase effect1 ?is contrav5es ! commonly accept$ !ory ( ! dissimilation ( tissue by /imulus1 & ! consequ5t depression ( response4 ,x is sugge/$ by ,wall] t ?is increase ( response aft] tetanisation may be due to ! hypo!tical evolution ( ,,co#b to :i* allusion has previ\sly be5 made4 ,illu/ration3 ,,fig4#ha4--;,,enhanc$ ,,response ,,9 ,,t9 ,,aft] ,,cont9u\s ,,/imulation ,t ,b !re is an exact correspond5ce betwe5 ?is ph5om5on & t exhibit$ by metals "u simil> conditions4 ,i give "h two sets ( records 7figs4 #hj1 #ha71 "o obta9$ ) plat9um & ! o!r ) t91 :i* demon/rate h[ ! response is enhanc$ aft] cont9u\s /imulation 9 a mann] exactly simil> to t notic$ 9 ! case ( n]ve4 ,! explanation :i* has be5 sugge/$ ) reg>d to ! /aircase effect--increas$ molecul> mobility due to removal ( sluggi%ness by repeat$ /imulation--w\ld appe> to be applicable 9 ?is case also4 ,x w\ld appe>1 !n1 t 9 all ! ph5om5a :i* we h /udi$ "u ! heads ( '/aircase' effect1 increase ( response aft] cont9u\s /imulation1 & fatigue1 !re is a simil>ity betwe5 ! obs]vations made ^u ! response ( muscle & n]ve on ! "o h&1 & t ( metals on ! o!r4 ,ev5 9 _! abnormalities we h se5 an agreem5t4 ,b among/ ^! ph5om5a !mselves1 ?\gh at fir/ sight s div]se1 !re is "s k9d ( cont9uity4 ,call+ all normal response positive1 = ! sake ( conv5i5ce1 we obs]ve its gradual modification1 correspond+ to *anges 9 ! molecul> condition ( ! sub/ance4 ,beg9n+ ) t case 9 :i* molecul> modification is extreme1 we f9d a maximum v>iation ( response f ! normal1 t is to say1 to negative4 ,cont9u$ /imulation1 h[ev]1 br+s back ! molecul> condition to normal1 z evid5c$ by ! progressive less5+ ( ! negative response1 culm9at+ 9 rev]sion to ! normal positive4 ,?is is equally true ( n]ve & metal4 ,9 ! next class ( ph5om5a1 ! modification ( molecul> condition is n s great4 ,x n[ exhibits itself m]ely z a relative in]tness1 & ! responses1 ?\gh positive1 are feeble4 ,"u cont9u$ /imulation1 !y increase 9 ! same direction z 9 ! la/ case1 t is to say1 f less positive to m positive1 be+ ! rev]se ( fatigue4 ,?is is evid5c$ alike by ! /aircase effect & by ! increase ( response aft] tetanisation1 se5 n only 9 n]ve b also 9 plat9um & t94 ,! sub/ance may next be 9 :at we call ! normal condition4 ,successive uni=m /imuli n[ evoke uni=m & equal positive responses1 t is to say1 !re is no fatigue4 ,b aft] int5se or long-cont9u$ /imulation1 ! sub/ance is ov]/ra9$4 ,! responses n[ und]go a *ange f positive to less positive2 fatigue1 t is to say1 appe>s4 ,aga91 "u v mu* prolong$ /imulation ! response may decl9e to z]o1 or ev5 und]go a rev]sal to negative1 a ph5om5on :i* we %all f9d in/anc$ 9 ! rev]s$ response ( ret9a "u ! long-cont9u$ /imulus ( light4 ,we mu/ !n recognise t a sub/ance may exi/ 9 v>i\s molecul> conditions1 :e!r due to int]nal *anges or to ! action ( /imulus4 ,! responses give u indications ( ^! conditions4 ,a complete cycle ( molecul> modifications c be trac$1 f ! abnormal negative to ! normal positive1 & !n aga9 to negative se5 9 rev]sal "u cont9u\s /imulation4 ,,footnotes3 #af ',consid]+ t we h no previ\s evid5ce ( any *emical or physical *ange 9 tetanis$ n]ve1 x seems to me n wor? :ile paus+ to deal ) ! criticism t x is n ,,co#b1 b some?+ else t has giv5 ! result4'--,wall]1 ,animal ,electricity1 p4#ei4 ,t ?is ph5om5on is nev]!less capable ( physical explanation w be %[n pres5tly4 #ag ,9 ord] to expla9 ! ph5om5a ( electric response1 "s physiologi/s assume t ! negative response is due to a process ( dissimilation1 or breakd[n1 & ! positive to a process ( assimilation1 or build+ up1 ( ! tissue4 ,! modifi$ or positive response 9 n]ve is ?us held to be due to assimilation2 aft] cont9u\s /imulation1 ?is process is suppos$ to be trans=m$ into "o ( dissimilation1 ) ! att5dant negative response4 ,h[ arbitr>y & unnecess>y su* assumptions are w become evid5t1 :5 ! abnormal & normal responses1 & _! trans=mation f "o to ! o!r1 are f\nd repeat$ 9 all details 9 metals1 :]e !re c be no "q ( ! processes ( assimilation or dissimilation4 ,,*apt] ,,xv ,,inorganic ,,response--,,relation ,,betwe5 ,,/imulus ,,& ,,response--,,sup]position ,,( ,,/imuli ,relation betwe5 /imulus & response--,magnetic analogue--,increase ( response ) increas+ ,/imulus--,?re%old ( response--,sup]position ( ,/imuli--,hy/]esis4 ,relation betwe5 /imulus & response4--,we h se5 :at extremely uni=m responses are giv5 by t91 :5 ! int5sity ( /imulus is ma9ta9$ con/ant4 ,h5ce x is obvi\s t ^! ph5om5a are n accid5tal1 b gov]n$ by def9ite laws4 ,?is fact becomes /ill m evid5t :5 we discov] h[ inv>iably response is increas$ by increas+ ! int5sity ( /imulus4 ,electrical response is due1 z we h se51 to a molecul> di/urbance1 ! /imulus caus+ a di/ortion f a position ( equilibrium4 ,9 deal+ ) ! subject ( ! relation betwe5 ! di/urb+ =ce & ! molecul> effect x produces1 x may be in/ructive to consid] c]ta9 analog\s physical ph5om5a 9 :i* molecul> deflections are also produc$ by a di/ort+ =ce4 ,magnetic analogue4--,let u consid] ! effect t a magnetis+ =ce produces on a b> ( s(t iron4 ,x is kn[n t ea* molecule 9 su* a b> is an individual magnet4 ,! b> z a :ole1 nev]!less1 exhibits no ext]nal magnetisation4 ,?is is held to be due to ! fact t ! molecul> magnets are turn$ ei!r 9 haphaz>d directions or 9 clos$ *a9s1 & !re is !re=e no resultant pol>ity4 ,b :5 ! b> is subject$ to a magnetis+ =ce by means1 say1 ( a sol5oid c>ry+ electrical curr5t1 ! individual molecules are ela/ically deflect$1 s t all ! molecul> magnets t5d to place !mselves along ! l9es ( magnetis+ =ce4 ,all ! nor? poles ?us po9t m or less "o way1 & ! s\? poles ! o!r4 ,! /rong] ! magnetis+ =ce1 ! ne>] d ! molecules approa* to a p]fect alignm5t1 & ! great] is ! induc$ magnetisation ( ! b>4 ,! int5sity ( ?is induc$ magnetisation may be measur$ by not+ ! deflection x produces on a freely susp5d$ magnet 9 a magnetomet]4 ,! =ce :i* produces t molecul> deflection1 to :i* ! magnetisation ( ! b> is imm$iately due1 is ! magnetis+ curr5t fl[+ r\nd ! sol5oid4 ,! magnetisation1 or ! molecul> effect1 is measur$ by ! deflection ( ! magnetomet]4 ,we may express ! relation betwe5 cause & effect by a curve 9 :i* ! abscissa repres5ts ! magnetis+ curr5t1 & ! ord9ate ! magnetisation produc$ 7fig4#hb74 ,illu/ration3 ,,fig4#hb4--;,,curve ,,( ,,magnetisation ,9 su* a curve we may r\ghly di/+ui% ?ree p>ts4 ,9 ! fir/1 :]e ! =ce is feeble1 ! molecul> deflection is slight4 ,9 ! next1 ! curve is rapidly asc5d+1 i4e4 a small v>iation ( impress$ =ce produces a relatively l>ge molecul> effect4 ,& la/ly1 a limit is rea*$1 z se5 9 ! ?ird "p1 :]e increas+ =ce produces v little fur!r effect4 ,9 ?is cause-&-effect curve1 ! fir/ "p is slightly convex to ! abscissa1 ! second /raight & asc5d+1 & ! ?ird concave4 ,increase ( response ) increas+ /imulus4--,we %all f9d 9 deal+ ) ! relation betwe5 ! /imulus & ! molecul> effect--i4e4 ! response--some?+ v simil>4 ,on gradually increas+ ! int5sity ( /imulus1 :i* may be done1 z already /at$1 by increas+ ! amplitude ( vibration1 x w be f\nd t1 beg9n+ ) feeble /imulation1 ?is increase is at fir/ slight1 !n m pron\nc$1 & la/ly %[s a t5d5cy to approa* a limit4 ,9 all ?is we h a p]fect p>allel to correspond+ ph5om5a 9 animal & vegetable response4 ,we saw t ! prop] inve/igation ( ?is subject 0 mu* complicat$1 9 ! case ( animal & vegetable tissues1 by ! appe>ance ( fatigue4 ,! comp>atively indefatigable nature ( t9 causes x to (f] great advantages 9 ! pursuit ( ?is inquiry4 ,i give bel[ two s]ies ( records made ) t94 ,! fir/ record1 fig4#hc1 is = increas+ amplitudes f #e to #dj by /eps ( #e4 ,! /imuli are imp>t$ at int]vals ( "o m9ute4 ,x w be notic$ t :]eas ! recov]y is complete 9 "o m9ute :5 ! /imulus is mod]ate1 x is n q complete :5 ! /imulus is /rong]4 ,! recov]y f ! effect ( /rong] /imulus is m prolong$4 ,ow+ to want ( complete recov]y1 ! base l9e is tilt$ slightly upw>d4 ,?is slight displacem5t ( ! z]o l9e does n mat]ially affect ! result1 provid$ ! %ift+ is slight4 ,illu/ration3 ,,fig4#hc4--,,records ,,( ,,responses ,,9 ,,t9 ,,) ,,increas+ ,,/imuli1 ,,amplitudes ,,( ,,vibration ,,f #e ,,to #dj ,! v]tical l9e to ! "r repres5ts #avolt4 ,,table ,,%[+ ,,! ,,increas+ ,,electric ,,response ,,due ,,to ,,increas+ ,,amplitude ,,( ,,vibration ------------------------------------- ,vibration amplitude ,e4,m4 v>iation ------------------------------------- #e #jbd volt #aj #jeg #bj #aaa #be #adc #cj #agj #ce #ahg #dj #bjd ------------------------------------- ,! next figure 7fig4#hd7 gives record ( responses ?r\gh a wid] range4 ,= accurate quantitative measurem5ts x is pref]able to wait till ! recov]y is complete4 ,we may accompli% ?is )9 ! limit$ space ( ! record+ photographic plate by mak+ ! record = "o m9ute2 dur+ ! re/ ( recov]y1 ! clockwork mov+ ! plate is /opp$ & ! galvanomet] spot ( light is cut (f4 ,?us ! next record />ts f a po9t ( complet$ recov]y1 :i* w be notic$ z a bright spot at ! beg9n+ ( ea* curve4 ,) /imulation ( high int5sity1 a t5d5cy w be notic$ = ! responses to approa* a limit4 ,illu/ration3 ,,fig4#hd4--;,a ,,second ,,set ,,( ,,records ,,) ,a ,,diff]5t ,,specim5 ,,( ,,t9 ,! amplitudes ( vibration are increas$ by /eps ( #aj1 f #bj to #afj4 7,! deflections are r$uc$ by int]pos+ a high ext]nal resi/ance47 ,illu/ration3 ,,fig4#he4--;,,effect ,,( ,,sup]position ,,on ,,t9 ,a s+le /imulus produces ! feeble effect %[n 9 ! fir/ response4 ,sup]position ( #e1 #i1 #ac su* /imuli produce ! succe$+ /rong] responses4 ,?re%old ( response4--,!re is a m9imum int5sity ( /imulus bel[ :i* !re is h>dly any visible response4 ,we may reg>d ?is po9t z ! ?re%old ( response4 ,?\gh app>5tly ineffective1 ! sublim9al /imuli produce "s lat5t effect1 :i* may be demon/rat$ by _! additive action4 ,! record 9 fig4#he %[s h[ individually feeble /imuli become m>k$ly effective by sup]position4 ,illu/ration3 ,,fig4#hf4--;,,incomplete ,,& ,,complete ,,fusion ,,( ,,effect ,,9 ,,t9 ,z ! frequ5cy ( /imulation is increas$ ! fusion becomes m & m complete4 ,v]tical l9e to ! "r repres5ts #avolt4 ,sup]position ( /imuli4--,! additive effect ( succe$+ /imuli w be se5 f ! above4 ,! fusion ( effect w be incomplete if ! frequ5cy ( /imulation be n suffici5tly great2 b x w t5d to be m complete ) high] frequ5cy ( /imulation 7fig4#hf74 ,we h "h a p>allel case to ! complete & incomplete tetanus ( muscles1 "u simil> conditions4 ,by ! addition ( ^! rapidly succe$+ /imuli1 a maximum effect is produc$1 & fur!r /imulation adds no?+ to ?is4 ,! effect is balanc$ by a =ce ( re/itution4 ,! response-curve ?us rises to its maximum1 aft] :i* ! deflection is held z x 7 rigid1 s long z ! vibration is kept up4 ,illu/ration3 ,,fig4#hg4--;,,cyclic ,,curve ,,= ,,maximum ,,effects ,,%[+ ,,hy/]esis ,x 0 f\nd t increas+ int5sities ( s+le /imuli produc$ correspond+ly increas$ responses4 ,! same is true also ( gr\ps ( /imuli4 ,! maximum effect produc$ by sup]position ( /imuli increases ) ! int5sity ( ! con/itu5t /imuli4 ,hy/]esis4--,allusion has already be5 made to ! increas$ responsiv5ess conf]r$ by prelim9>y /imulation 7see p4#abg74 ,be+ desir\s ( f9d+ out 9 :at mann] ?is is br\ght ab\t1 ,i took a s]ies ( obs]vations = an entire cycle1 t is to say1 a s]ies ( obs]vations 7 tak5 = maximum effects1 />t+ f amplitude ( vibration ( #aj & end+ 9 #ajj1 & backw>ds f #ajj to #aj4 ,effect ( hy/]esis is v cle>ly se5 7see ,a1 fig4#hg72 !re is a consid]able div]g5ce betwe5 ! =w>d & return curves1 ! return curve be+ high]4 ,on repeat+ ! cycle sev]al times1 ! div]g5ce is f\nd v mu* r$uc$1 ! wire on ! :ole is f\nd to assume a m con/ant s5sitiv5ess4 ,9 ?is /eady condition1 g5]ally speak+1 ! s5sitiv5ess = small] amplitude ( vibration is f\nd to be great] ?an at ! v beg9n+1 b ! rev]se is ! case = /rong] int5sity ( /imulation4 ,effect ( anneal+4--,i repeat$ ! exp]im5t ) ! same wire1 aft] p\r+ hot wat] into ! cell & all[+ x to cool to ! old temp]ature4 ,f ! cyclic curve 7,b1 fig4#hg7 x w be se5 7#a7 t ! s5sitiv5ess has become v mu* enhanc$2 7#b7 t !re is relatively less div]g5ce betwe5 ! =w>d & return curves4 ,ev5 ?is div]g5ce practically disappe>$ at ! ?ird cycle1 :5 ! =w>d & backw>d curves co9cid$ 7,c1 fig4#hg74 ,! above results %[ 9 :at mann] ! excitability ( ! wire is enhanc$ by purely physical means4 ,x is v curi\s to notice t addition ( ,na#b;,,co#c solution 7see ,*ap4 ,,xv--,action ( ,/imulants7 produces enhancem5t ( responsive p[] simil> to t produc$ by anneal+2 t is to say1 n only is !re a great increase ( s5sitiv5ess1 b !re is also a r$uction ( hy/]esis4 ,,*apt] ,,xvi ,,inorganic ,,response--,,effect ,,( ,,*emical ,,reag5t ,action ( *emical reag5ts--,action ( /imulants on metals--,action ( depressants on metals--,effect ( 'poisons' on metals--,opposite effect ( l>ge & small doses4 ,we h se5 t ! ultimate crit]ion ( ! physiological "* ( electric response is held to be its abolition :5 ! sub/ance is subject$ to ^? *emical reag5ts :i* act z poisons4 ,illu/ration3 ,,fig4#hh4--;,,action ,,( ,,poison ,,9 ,,aboli%+ ,,response ,,9 ,,n]ve 7,,wall]7 ,action ( *emical reag5ts4--,( ^! reag5ts1 "s are univ]sal 9 _! action1 among/ :i* /rong solutions ( acids & alkalis1 & salts l m]curic *loride1 may be cit$4 ,^! act z p[]ful toxic ag5ts1 kill+ ! liv+ tissue1 & caus+ electric response to disappe>4 7,see fig4#hh47 ,x mu/1 h[ev]1 be rememb]$ t !re are aga9 specific poisons :i* may affect "o k9d ( tissue & n o!rs4 ,poisons 9 g5]al may be reg>d$ z extreme cases ( depressants4 ,z an example ( ^? :i* produce mod]ate physiological depression1 potassium bromide may be m5tion$1 & ?is also dim9i%es electric response4 ,!re are o!r *emical reag5ts1 on ! o!r h&1 :i* produce ! opposite effect ( increas+ ! excitability & caus+ a correspond+ exaltation ( electric response4 ,we %all n[ proce$ to inquire :e!r ! response ( inorganic bodies is affect$ by *emical reag5ts1 s t _! excitability is exalt$ by "s1 & depress$ or aboli%$ by o!rs4 ,%\ld x prove to be s1 ! la/ te/ w h be5 fulfill$1 & t p>allelism :i* has be5 already demon/rat$ ?r\gh\t a wide range ( ph5om5a1 betwe5 ! electric response ( animal tissues on ! "o h&1 & t ( plants & metals on ! o!r1 w be completely e/abli%$4 ,action ( /imulants on metals4--,we %all fir/ /udy ! /imulat+ action ( v>i\s *emical reag5ts4 ,! me?od ( proc$ure is to take a s]ies ( normal responses to uni=m /imuli1 ! electrolyte be+ wat]4 ,! *emical reag5t ^: effect is to be obs]v$ is n[ add$ 9 small quantity to ! wat] 9 ! cell1 & a second s]ies ( responses tak51 us+ ! same /imulus z be=e4 ,g5]ally speak+1 ! influ5ce ( ! reag5t is manife/$ 9 a %ort p]iod1 b !re may be occasional in/ances :]e ! effect takes "s "t to develop fully4 ,we mu/ rememb] t by ! introduction ( ! *emical reag5t "s *ange may be produc$ 9 ! int]nal resi/ance ( ! cell4 ,! effect ( ?is on ! deflection is elim9at$ by int]pos+ a v high ext]nal resi/ance 7f "o to five megohms7 9 comp>ison ) :i* ! int]nal resi/ance ( ! cell is negligible4 ,! fact t ! introduction ( ! reag5t did n produce any v>iation 9 ! total resi/ance ( ! circuit 0 demon/rat$ by tak+ two deflections1 due to a def9ite fraction ( a volt1 be=e & aft] ! introduction ( ! reag5t4 ,^! deflections 7 f\nd equal4 ,illu/ration3 ,,fig4#hi4--,,/imulat+ ,,action ,,( ,na#b;,,co#c ,,on ,,t9 ,i fir/ give a record ( ! /imulat+ action ( sodium c>bonate on t91 :i* w become evid5t by a comp>ison ( ! responses be=e & aft] ! introduction ( ,na#b;,,co#c 7fig4#hi74 ,! next record %[s ! effect ( ! same reag5t on plat9um 7fig4#ij74 ,illu/ration3 ,,fig4#ij4--,,/imulat+ ,,action ,,( ,na#b;,,co#c ,,on ,,plat9um ,action ( depressants4--,c]ta9 o!r reag5ts1 aga91 produce an opposite effect4 ,t is to say1 !y dim9i% ! int5sity ( response4 ,! record giv5 on ! next page 7fig4#ia7 %[s ! depress+ action ( #ajp]c5t4 solution ( ,k,br on t94 ,illu/ration3 ,,fig4#ia4--;,,depress+ ,,effect ,,( ,,kbr 7#aj,,p] ,,c5t47 ,,on ,,! ,,response ,,( ,,t9 ,effect ( 'poison4'--,liv+ tissues are kill$1 & _! electric responses are at ! same "t aboli%$ by ! action ( poisons4 ,x is v curi\s t v>i\s *emical reag5ts are simil>ly effective 9 kill+ ! response ( metals4 ,i give bel[ a record 7fig4#ib7 to %[ h[ oxalic acid aboli%es ! response4 ,! depressive effect ( ?is reag5t is s great t a /r5g? ( "o "p 9 #aj1jjj is (t5 suffici5t to produce complete abolition4 ,ano!r notable po9t ) ref]5ce to ! action ( ?is reag5t is ! p]si/5ce ( aft]-effect4 ,?is w be cle>ly se5 f an acc\nt ( ! foll[+ exp]im5t4 ,! two wires ,a & ,b1 9 ! cell fill$ ) wat]1 7 f\nd to give equal responses4 ,! wires 7 n[ lift$ (f1 & "o wire ,b 0 t\*$ ) dilute oxalic acid4 ,all traces ( acid 7 next remov$ by rubb+ ! wire ) clo? "u a /ream ( wat]4 ,on replac+ ! wire 9 ! cell1 ,a gave ! usual response1 :]eas t ( ,b 0 f\nd to be aboli%$4 ,! depression produc$ is s great & passes 9 s deep t ,i h (t5 fail$ to revive ! response1 ev5 aft] rubb+ ! wire ) em]y pap]1 by :i* ! molecul> lay] on ! surface mu/ h be5 remov$4 ,illu/ration3 ,,fig4#ib4--;,,abolition ,,( ,,response ,,by ,,oxalic ,,acid ,we h se5 9 ! molecul> model 7fig4#fb1 d1 e7 h[ ! atta9m5t ( maximum is delay$1 ! response dim9i%$1 & ! recov]y prolong$ or arre/$ by increase ( friction or r$uction ( molecul> mobility4 ,x w\ld appe> z if ! reag5ts :i* act z poisons produc$ "s k9d ( molecul> arre/4 ,! foll[+ records se5 to l5d support to ?is view4 ,if ! oxalic acid is appli$ 9 l>ge quantities1 ! abolition ( response is complete4 ,b on c>efully add+ j ! prop] am\nt ,i f9d t ! fir/ /imulus evokes a responsive electric twit*1 :i* is less ?an ! normal1 & ! p]iod ( recov]y is v mu* prolong$ f ! normal "o m9ute be=e1 to five m9utes aft]1 ! application ( ! reag5t 7fig4#ic1 a74 ,9 ano!r record ! arre/ is m pron\nc$1 i4e4 !re is n[ no recov]y 7fig4#ic1 b74 ,note also t ! maximum is atta9$ mu* lat]4 ,/imuli appli$ aft] ! arre/ produce no effect1 z if ! molecul> me*anism became1 z x 71 clogg$ or lock$ up4 ,9 connection ) ?is x is int]e/+ to note t ! effect ( v]atr9e poison on muscle is some:at simil>4 ,?is reag5t n only dim9i%es ! excitability1 b causes a v great prolongation ( ! p]iod ( recov]y4 ,9 connection ) ! action ( *emical reag5ts ! foll[+ po9ts are notewor?y4 ,illu/ration3 ,,fig4#ic4--',,molecul> ,,arre/' ,,by ,,! ,,action ,,( ',,poison' ,9 ea*1 curves to ! left %[ ! normal response1 curve to ! "r %[s ! effect ( poison4 ,9 7a7 ! arre/ is evid5c$ by prolongation ( p]iod ( recov]y4 ,9 7b7 !re is no recov]y4 7#a7 ,! effect ( ^! reag5ts is n only to increase or dim9i% ! height ( ! response-curve1 b also to modify ! "t relations4 ,by ! action ( "s ! lat5t p]iod is dim9i%$1 o!rs produce a prolongation ( ! p]iod ( recov]y4 ,"s curi\s effects produc$ by ! *ange ( "t relations h be5 notic$ 9 ! acc\nt giv5 ( diphasic v>iation 7see p4#aac74 7#b7 ,! effect produc$ by a *emical reag5t dep5ds to "s ext5t on ! previ\s condition ( ! wire4 7#c7 ,a c]ta9 "t is requir$ = ! full developm5t ( ! effect4 ,) "s reag5ts ! full effect takes place almo/ in/antane\sly1 :ile ) o!rs ! effect takes place sl[ly4 ,aga9 ! effect may ) "t rea* a maximum1 aft] :i* !re may be a slight decl9e4 7#d7 ,! aft]-effects ( ! reag5ts may be transitory or p]si/5t2 t is to say1 9 "s cases ! removal ( ! reag5t causes ! responses to rev]t to ! normal1 :ile 9 o!rs ! effect p]si/s ev5 aft] ! removal ( all traces ( ! reag5t4 ,opposite effects ( l>ge & small doses4--,!re rema9s a v curi\s ph5om5on1 kn[n n only to /ud5ts ( physiological response b also kn[n 9 m$ical practice1 namely t ( ! opposite effects produc$ by ! same reag5t :5 giv5 9 l>ge or 9 small doses4 ,"h1 too1 we h ! same ph5om5a reproduc$ 9 an extraord9>y mann] 9 inorganic response4 ,! same reag5t :i* becomes a 'poison' 9 l>ge quantities may act z a /imulant :5 appli$ 9 small doses4 ,?is is se5 9 record fig4#id1 9 :i* 7a7 gives ! normal responses 9 wat]2 ,,kho solution 0 n[ add$ s z to make ! /r5g? ?ree p>ts 9 #a1jjj1 & 7b7 %[s ! consequ5t enhancem5t ( response4 ,a fur!r quantity ( ,,kho 0 add$ s z to increase ! /r5g? to ?ree p>ts 9 #ajj4 ,?is caus$ a complete abolition 7c7 ( response4 ,illu/ration3 ,,fig4#id4--,,opposite ,,effects ,,( ,,small ,,& ,,l>ge ,,doses 7,,t97 7a7 is ! normal response2 7b7 is ! /imulat+ action ( small dose ( pota% 7#cp>ts 9 #a1jjj72 7c7 is ! abolition ( response ) a /rong] dose 7#cp>ts 9 #ajj74 ,x w ?us be se5 t z 9 ! case ( animal tissues & ( plants1 s also 9 metals1 ! electrical responses are exalt$ by ! action ( /imulants1 l[]$ by depressants1 & completely aboli%$ by c]ta9 o!r reag5ts4 ,! p>allelism w ?us be f\nd complete 9 e detail betwe5 ! ph5om5a ( response 9 ! organic & ! inorganic4 ,,*apt] ,,xvii ,,on ,,! ,,/imulus ,,( ,,light ,,& ,,ret9al ,,curr5ts ,visual impulse3 7#a7 *emical !ory2 7#b7 electrical !ory--,ret9al curr5ts--,normal response positive--,inorganic response "u /imulus ( light--,typical exp]im5t on ! electrical effect induc$ by light4 ,! effect ( ! /imulus ( light on ! ret9a is p]ceiv$ 9 ! bra9 z a visual s5sation4 ,! process by :i* ! e!r-wave di/urbance causes ?is visual impulse is /ill v obscure4 ,two !ories may be advanc$ 9 explanation4 7#a7 ,*emical !ory4--,accord+ to ! fir/1 or *emical1 !ory1 x is suppos$ t c]ta9 visual sub/ances 9 ! ret9a are affect$ by light1 & t vision orig9ates f ! metabolic *anges produc$ 9 ^! visual sub/ances4 ,x is also suppos$ t ! metabolic *anges consi/ ( two phases1 ! upw>d1 con/ructive1 or anabolic phase1 & ! d[nw>d1 de/ructive1 or katabolic phase4 ,v>i\s visual sub/ances by _! anabolic or katabolic *anges are suppos$ to produce ! v>iations ( s5sation ( light & col\r4 ,?is !ory1 z w be se51 is v complex1 & !re are c]ta9 ob/acles 9 ! way ( its acceptance4 ,x is1 = in/ance1 difficult to see h[ ?is v quick visual process c\ld be due to a comp>atively sl[ *emical action1 consi/+ ( ! de/ructive break+-d[n ( ! tissue1 foll[$ by its r5ovation4 ,"s support 0 at fir/ giv5 to ?is *emical !ory by ! blea*+ action ( light on ! visual purple pres5t 9 ! ret9a1 b x has be5 f\nd t ! pres5ce or abs5ce ( visual purple c\ld n be ess5tial to vision1 & t its function1 :5 pres5t1 is ( only second>y importance4 ,= x is well kn[n t 9 ! mo/ s5sitive portion ( ! human ret9a1 ! fovea c5tralis1 ! visual purple is want+2 x is also f\nd to be completely abs5t f ! ret9 ( _m animals possess+ ke5 sight4 7#b7 ,electrical !ory4--,! second1 or electrical1 !ory supposes t ! visual impulse is ! concomitant ( an electrical impulse2 t an electrical curr5t is g5]at$ 9 ! ret9a "u ! incid5ce ( light1 & t ?is is transmitt$ to ! bra9 by ! optic n]ve4 ,!re is mu* to be said 9 fav\r ( ?is view1 = x is an und\bt$ fact1 t light gives rise to ret9al curr5ts1 & t1 conv]sely1 an electrical curr5t suitably appli$ causes ! s5sation ( light4 ,ret9al curr5ts4--,holmgr51 ,dew>1 ,mc,kendrick1 ,kuhne1 ,/e9]1 & o!rs h %[n t illum9ation produces electric v>iation 9 a fre%ly excis$ eye4 ,ab\t ?is g5]al fact ( ! electrical response !re is a widespread agreem5t1 b !re is "s diff]5ce ( op9ion z reg>ds ! sign ( ?is response imm$iately on ! application1 cessation1 & dur+ ! cont9uance ( light4 ,^! slight discrepancies may be p>tly due to ! unsatisfactory nom5clature--z reg>ds use ( t]ms positive & negative--hi!rto 9 vogue & p>tly also to ! diff]+ /ates ( ! excis$ eyes obs]v$4 ,wall]1 9 8 excell5t & detail$ "w on ! ret9al curr5ts ( ! frog1 has %[n h[ ! sign ( response is rev]s$ 9 ! moribund condition ( ! eye4 ,z to ! confusion aris+ f our pres5t t]m9ology1 we mu/ rememb] t ! t]m positive or negative is us$ ) reg>d to a curr5t ( ref]5ce--! s-call$ curr5t ( injury4 ,illu/ration3 ,,fig4#ie4 ,,ret9al ,,response ,,to ,,light ,! curr5t ( response is f ! n]ve to ! ret9a4 ,:5 ! two galvanometric contacts are made1 "o ) ! cut end ( ! n]ve1 & ! o!r on ! un9jur$ cornea1 a curr5t ( injury is f\nd :i* 9 ! eye is f ! n]ve to ! ret9a4 ,9 ! normal fre%ly excis$ eye1 ! curr5t ( response due to ! action ( light on ! ret9a is always f ! n]ve1 :i* is n directly /imulat$ by light1 to ! ret9a1 t is1 f ! less excit$ to ! m excit$ 7fig4#ie74 ,?is curr5t ( response fl[s1 !n1 9 ! same direction z ! exi/+ curr5t ( ref]5ce--! curr5t ( injury--& may !re=e be call$ positive4 ,un=tunately ! curr5t ( injury is v (t5 apt to *ange its sign2 x !n fl[s ?r\gh ! eye f ! cornea to ! n]ve4 ,& n[1 ?\gh ! curr5t ( response due to light may rema9 un*ang$ 9 direction1 /ill1 ow+ to ! rev]sal ( ! curr5t ( ref]5ce1 x w appe> z negative4 ,t is to say1 ?\gh its absolute direction is ! same z be=e1 its relative direction is alt]$4 ,i h already advocat$ ! use ( ! t]m positive = curr5ts :i* fl[ t[>ds ! /imulat$1 & negative = ^? ^: fl[ is away f ! /imulat$4 ,if su* a conv5tion be adopt$1 no confusion c arise1 ev5 :51 z 9 ! giv5 cases1 ! curr5ts ( injury und]go a *ange ( direction4 ,normal response positive4--,! normal effect ( light on ! ret9a1 z notic$ by all ! obs]v]s already m5tion$1 is a positive v>iation1 dur+ exposure to light ( n too long duration4 ,cessation ( light is foll[$ by recov]y4 ,on ^! po9ts !re is g5]al agreem5t among/ inve/igators4 ,deviations are reg>d$ z due to abnormal conditions ( ! eye1 ow+ to r\gh usage1 or to ! rapid approa* ( dea?4 ,= j z 9 ! dy+ plant we f\nd occasional rev]sals f negative to positive response1 s 9 ! dy+ ret9a ! response may und]go *anges f ! normal positive to negative4 ,! sign ( response1 z we h already se5 9 num]\s cases1 dep5ds v mu* on ! molecul> condition ( ! s5sitive sub/ance1 & if ?is condition be 9 any way *ang$1 x is n surpris+ t ! "* ( ! response %\ld also und]go alt]ation4 ,unlike muscle 9 ?is1 successive ret9al responses exhibit little *ange1 =1 g5]ally speak+1 fatigue is v slight1 ! ret9a recov]+ quickly ev5 "u /rong light if ! exposure be n too long4 ,9 exceptional cases1 h[ev]1 fatigue1 or its conv]se1 ! /aircase effect1 may be obs]v$4 ,inorganic response "u ! /imulus ( light4--,x may n[ be ask$ :e!r su* a complex vital ph5om5on z ret9al response c\ld h its c\nt]p>t 9 non-liv+ response4 ,tak+ a rod ( silv]1 we may beat out "o end into ! =m ( a holl[ cup1 s5sitis+ ! inside by expos+ x = a %ort "t to vap\r ( brom9e4 ,! cup may n[ be fill$ ) wat]1 & connection made ) a galvanomet] by non-pol>isable electrodes4 ,!re w n[ be a curr5t due to diff]5ce betwe5 ! inn] surface & ! rod4 ,?is may be balanc$1 h[ev]1 by a comp5sat+ ,e4,m4,f4 ,illu/ration3 ,,fig4#if4--,,record ,,( ,,responses ,,to ,,light ,,giv5 ,,by ,,! ,,s5sitive ,,cell ,?ick l9es repres5t ! effect dur+ illum9ation1 dott$ l9es ! recov]y 9 d>kness4 ,note ! prelim9>y negative twit*1 :i* is sometimes also obs]v$ 9 responses ( frog's ret9a4 ,we h ?us an arrangem5t some:at resembl+ ! eye1 ) a s5sitive lay] correspond+ to ! ret9a1 & ! less s5sitive rod correspond+ to ! conduct+ n]ve-/ump 7fig4#if1 a74 ,! app>atus is next plac$ inside a black box1 ) an ap]ture at ! top4 ,by means ( an incl9$ mirror1 light may be ?r[n d[n ^u ! s5sitive surface ?r\gh ! op5+4 ,on expos+ ! s5sitive surface to light1 ! balance is at once di/urb$1 & a responsive curr5t ( positive "* produc$4 ,! curr5t1 t is to say1 is f ! less to ! m /imulat$ s5sitive lay]4 ,on ! cessation ( light1 !re is fairly quick recov]y 7fig4#if1 b74 ,! "* & ! int5sity ( ,e4,m4 v>iation ( ! s5sitive cell dep5d to "s ext5t on ! process ( prep>ation4 ,! p>ticul> cell ) :i* mo/ ( ! foll[+ exp]im5ts 7 c>ri$ out usually gave rise to a positive v>iation ( ab\t #jjhvolt :5 act$ on = "o m9ute by ! light ( an inc&esc5t gas-burn] :i* 0 plac$ at a di/ance ( #ej;cm4 ,typical exp]im5t on ! electrical effect induc$ by light4--,?is subject ( ! production ( an electrical curr5t by ! /imulus ( light w\ld appe> at fir/ sight v complex4 ,b we %all be able to advance naturally to a cle> und]/&+ ( its mo/ complicat$ ph5om5a if we g ?r\gh a prelim9>y consid]ation ( an ideally simple case4 ,we h se51 9 our exp]im5ts on ! me*anical /imulation (1 = example1 t91 t a diff]5ce ( electric pot5tial 0 induc$ betwe5 ! m /imulat$ & less /imulat$ p>ts ( ! same rod1 & t an action curr5t c\ld ?us be obta9$1 on mak+ suitable electrolytic connections4 ,:e!r ! m excit$ 0 z9coid or cuproid dep5d$ on ! sub/ance & its molecul> condition4 ,let u n[ imag9e ! metal rod flatt5$ into a plate1 & "o face /imulat$ by light1 :ile ! o!r is protect$4 ,w\ld !re be a diff]5ce ( pot5tial induc$ betwe5 ! two faces ( ?is same %eet ( metal8 ,let two blocks ( p>aff9 be tak5 & a l>ge hole drill$ ?r\gh bo?4 ,next1 place a %eet ( metal betwe5 ! blocks1 & p\r melt$ p>aff9 r\nd ! edge to seal up ! junction1 ! two op5 ends be+ also clos$ by panes ( glass4 ,we %all h !n two comp>tm5ts sep>at$ by ! %eet ( metal1 & ^! comp>tm5ts may be fill$ ) wat] ?r\gh ! small ap]tures at ! top 7fig4#ig1 a74 ,illu/ration3 ,,fig4#ig 7a7 ,a1 ,b are ! two faces ( a brom9at$ %eet ( silv]4 ,"o face1 say ,a1 is act$ on by light4 ,! curr5t ( response is f ,b to ,a1 across ! plate4 ,illu/ration3 ,,fig4#ig 7b74--,,record ,,( ,,responses ,,obta9$ ,,f ,,! ,,above ,,cell ,t5 seconds' exposure to light foll[$ by fifty seconds' recov]y 9 ! d>k4 ,?ick l9es repres5t action 9 light1 dott$ l9es repres5t recov]y4 ,! two liquid masses 9 ! sep>at$ *amb]s ?us make p]fect electrolytic contacts ) ! two faces ,a & ,b ( ! %eet ( metal4 ,^! two faces may be put 9 connection ) a galvanomet] by means ( two non-pol>isable electrodes1 ^: ends dip into ! two *amb]s4 ,if ! %eet ( metal h be5 prop]ly anneal$1 !re w n[ be no diff]5ce ( pot5tial betwe5 ! two faces1 & no curr5t 9 ! galvanomet]4 ,if ! two faces are n molecul>ly simil>1 h[ev]1 !re w be a curr5t1 & ! electrical effects to be subsequ5tly describ$ w act additively1 9 an algebraical s5se4 ,let "o face n[ be expos$ to ! /imulus ( light4 ,a responsive curr5t w be f\nd to fl[1 f ! less to ! m /imulat$ face1 9 "s cases1 & 9 o!rs 9 an opposite direction4 ,x appe>s at fir/ v curi\s t ?is diff]5ce ( electric pot5tial %\ld be ma9ta9$ betwe5 opposite faces ( a v ?9 & highly conduct+ %eet ( metal1 ! int]v5+ di/ance betwe5 ! oppos$ surfaces be+ s extremely small1 & ! electrical resi/ance q inf9itesimal4 ,a homog5e\s %eet ( metal has become by ! unequal action ( light1 molecul>ly speak+1 het]og5e\s4 ,! two oppos$ surfaces are ?r[n into opposite k9ds ( electric condition1 ! result ( :i* is z if a c]ta9 ?ickness ( ! %eet1 electrically speak+1 7 made z9c-l1 & ! re/ copp]-l4 ,f su* unfamili> conceptions1 we %all n[ pass easily to o!rs to :i* we are m accu/om$4 ,in/ead ( two oppos$ surfaces1 we may obta9 a simil> response by unequally light+ diff]5t portions ( ! same surface4 ,tak+ a %eet ( metal1 we may expose "o half1 say ,a1 to light1 ! o!r half1 ,b1 be+ scre5$4 ,electrolytic contacts are made by plung+ ! two limbs 9 two vessels :i* are 9 connection ) ! two non-pol>isable electrodes ,e & ,e' 7fig4#ih1 a74 ,on illum9ation ( ,a & ,b alt]nately1 we %all n[ obta9 curr5ts fl[+ alt]nately 9 opposite directions4 ,illu/ration3 ,,fig4#ih4--,,modification ,,( ,,! ,,s5sitive ,,cell ,j z 9 ! /ra9 cells ! galvanomet] contact 0 transf]r$ f ! electrolytic "p to ! metallic "p ( ! circuit1 s we may next1 9 an exactly simil> mann]1 cut ?is plate into two1 & connect ^! directly to ! galvanomet]1 electrolytic connection be+ made by p>tially plung+ !m into a cell conta9+ wat]4 ,! po/]ior surfaces ( ! two half-plates may be cov]$ ) a non-conduct+ coat+4 ,& we arrive at a typical photo-electric cell 7fig4#ih1 b74 ,^! consid]ations w %[ t ! eye is practically a photo-electric cell4 ,illu/ration3 ,,fig4#ii4--,,responses ,,to ,,light ,,9 ,,frog',s ,,ret9a ,illum9ation ,l = "o m9ute1 recov]y 9 d>k = two m9utes dur+ obscurity ,d4 7,wall]47 ,we %all n[ give detail$ exp]im5tal results obta9$ ) ! s5sitive silv]-bromide cell1 & comp>e its response-curve ) ^? ( ! ret9a4 ,a s]ies ( uni=m light /imuli gives rise to uni=m responses1 :i* %[ v little sign ( fatigue4 ,h[ simil> ^! response-curves are to ^? ( ! ret9a w be se5 f a pair ( records giv5 bel[1 :]e fig4#ii %[s responses ( frog's ret9a1 & fig4#ajj gives ! responses obta9$ ) ! s5sitive silv] cell 7fig4#ajj74 ,x 0 said t ! responses ( ! ret9a are uni=m4 ,?is is only approximately true4 ,9 addition to num]\s cases ( uni=m responses1 ,wall] f9ds in/ances ( '/aircase' increase1 & its opposite1 slight fatigue4 ,9 ! record "h giv5 ( ! silv] cell1 ! /aircase effect is se5 at ! beg9n+1 & foll[$ by slight fatigue4 ,i h o!r records :]e = a v long "t ! responses are p]fectly uni=m1 !re be+ no sign ( fatigue4 ,illu/ration3 ,,fig4#ajj4--,,responses ,,9 ,,s5sitive ,,silv] ,,cell ,illum9ation = "o m9ute & obscurity = "o m9ute4 ,?ick l9e repres5ts record dur+ illum9ation1 dott$ l9e recov]y dur+ obscurity4 ,ano!r curi\s ph5om5on sometimes obs]v$ 9 ! response ( ret9a is an occasional slight increase ( response imm$iately on ! cessation ( light1 aft] :i* !re is ! f9al recov]y4 ,an indication ( ?is is se5 9 ! second & f\r? curves 9 fig4#ii4 ,curi\sly en\gh1 ?is abnormality is also occasionally met ) 9 ! responses ( ! silv] cell1 z se5 9 ! fir/ two curves ( fig4#ajj4 ,o!r in/ances w be giv5 lat]4 ,,*apt] ,,xviii ,,inorganic ,,response--,,influ5ce ,,( ,,v>i\s ,,conditions ,,on ,,! ,,response ,,to ,,/imulus ,,( ,,light ,effect ( temp]ature--,effect ( increas+ l5g? ( exposure--,relation betwe5 int5sity ( light & magnitude ( response--,aft]-oscillation--,abnormal effects3 7#a7 prelim9>y negative twit*2 7#b7 rev]sal ( response2 7#c7 transi5t positive twit* on cessation ( light2 7#d7 decl9e & rev]sal--,rsum4 ,we %all next proce$ to /udy ! effect1 on ! response ( ! s5sitive cell1 ( all ^? conditions :i* influ5ce ! normal response ( ! ret9a4 ,we %all !n briefly inquire :e!r ev5 ! abnormalities sometimes met ) 9 ret9al responses h n _! p>allel 9 ! responses giv5 by ! inorganic4 ,illu/ration3 ,,fig4#aja4--;,,influ5ce ,,( ,,temp]ature ,,on ,,response ,illum9ation#bj1 obscurity#dj4 ,9 7a7 is %[n a s]ies ( responses at #bj;,c4--! record exhibits slight fatigue4 7b7 is ! slight irregul> response at #ej;,c4 7c7 is ! record on re-cool+2 x exhibits '/aircase' increase4 ,effect ( temp]ature4--,x has be5 f\nd t :5 ! temp]ature is rais$ above a c]ta9 po9t1 ret9al response %[s rapid dim9ution4 ,on cool+1 h[ev]1 response reappe>s1 ) its orig9al int5sity4 ,9 ! response giv5 by ! s5sitive cell1 ! same peculi>ity is notic$4 ,i give bel[ 7fig4#aja1 a7 a set ( response-curves = #bj;,c4 ,^! responses1 aft] %[+ slight fatigue1 became fairly con/ant4 ,on rais+ ! temp]ature to #ej;,c4 response practically disappe>$ 7#aja1 b74 ,b on cool+ to ! fir/ temp]ature aga91 x reappe>$1 ) its orig9al if n slightly great] int5sity 7fig4#aja1 c74 ,a curi\s po9t is t :ile 9 record 7a71 be=e w>m+1 slight fatigue is obs]v$1 9 7c71 aft] cool+1 ! rev]se1 or /aircase effect1 appe>s4 ,illu/ration3 ,,fig4#ajb4--,,response-,,curves ,,= ,,increas+ ,,duration ,,( ,,illum9ation ,,f #a ,,to #aj ,9 7a7 ! s\rce ( light 0 at a di/ance ( #ej;cm42 9 7b7 x 0 at a di/ance ( #be;cm4 ,note ! aft]-oscillation4 ,effect ( increas+ l5g? ( exposure4--,if ! int5sity ( light be kept con/ant1 ! magnitude ( response ( ! s5sitive cell increases ) l5g? ( exposure4 ,b ?is soon rea*es a limit1 aft] :i* increase ( duration does n increase magnitude ( effect4 ,too long an exposure may h[ev]1 ow+ to fatigue1 produce an actual decl9e4 ,i give "h two sets ( curves 7fig4#ajb7 illu/rat+ ! effect ( l5g!n+ exposure4 ,! int5sities ( light 9 ! two cases are z #a to #d4 ,! inc&esc5t burn] 0 9 ! two cases at di/ances #ej & #be;cm4 respectively4 ,x w be obs]v$ t beyond eight seconds' exposure ! responses are approximately uni=m4 ,ano!r noticeable fact is t ) long exposure !re is an aft]-oscillation4 ,?is gr[+ effect ) l5g!n+ exposure & atta9m5t ( limit is exactly p>allel$ by responses ( ret9a "u simil> conditions4 ,relation betwe5 int5sity ( light & magnitude ( response4--,9 ! responses ( ret9a1 x is f\nd t increas+ int5sity ( light produces an increas+ effect4 ,b ! rate ( increase is n uni=m3 increase ( effect does n keep pace ) increase ( /imulus4 ,?us a curve giv+ ! relation betwe5 /imulus & response is concave to ! axis :i* repres5ts ! /imulus4 ,! same is true ( ! s5sation ( light4 ,t is to say1 )9 wide limits1 int5sity ( s5sation does n increase s rapidly z /imulus4 ,?is p>ticul> relation betwe5 /imulus & effect is also exhibit$ 9 a rem>kable mann] by ! s5sitive cell4 ,= a con/ant s\rce ( light ,i us$ an inc&esc5t burn]1 & graduat$ ! int5sity ( ! incid5t light by v>y+ its di/ance f ! s5sitive cell4 ,! int5sity ( light incid5t on ! cell1 :5 ! inc&esc5t burn] is at a di/ance ( #aej;cm41 has be5 tak5 z ! arbitr>y unit4 ,9 ord] to make all[ance = ! possible effects ( fatigue ,i took two successive s]ies ( responses 7fig4#ajc74 ,9 ! fir/1 records 7 tak5 ) int5sities dim9i%+ f #g to #a1 & imm$iately aft]w>ds increas+ f #a to #g1 9 ! second4 ,illu/ration3 ,,fig4#ajc4--,,responses ,,( ,,s5sitive ,,cell ,,to ,,v>i\s ,,int5sities ,,( ,,light ,on ! left ! responses are = dim9i%+ int5sities 9 ! ratios ( #g1 #e1 #c1 & #a4 ,on ! "r !y are = ! increas+ int5sities #a1 #c1 #e1 & #g4 ,! ?ick l9es are records dur+ exposures ( "o m9ute2 ! dott$ l9es repres5t recov]ies = "o m9ute4 ,,table ,,giv+ ,,response ,,to ,,v>y+ ,,int5sities ,,( ,,light 7,! int5sity ( an inc&esc5t gas-burn] at a di/ance ( #aej;cm4 is tak5 z unit47 ---------------------------------------- -------------------------- ,response ,response ,int5sity 7,light 7,light ,mean ,value 9 volt ( ,light dim9i%+7 increas+7 ---------------------------------------- -------------------------- #g #dc #ci #da #fcj #aj- volt #e #ca #bi #cj #dfa #c #ahe #age #ah #bgg #a #aj #i #ie #adf ---------------------------------------- -------------------------- ,z ! z]o po9t 0 slightly %ift$ dur+ ! c\rse ( ! exp]im5t1 ! deflection 9 ea* curve 0 measur$ f a l9e jo9+ ! beg9n+ ( ! response to ! end ( its recov]y4 ,a mean deflection1 correspond+ to ea* int5sity1 0 obta9$ by tak+ ! av]age ( ! desc5d+ & asc5d+ read+s4 ,! two sets ( read+s did n1 h[ev]1 v>y to any m>k$ ext5t4 ,! deflections correspond+ to ! int5sities #a1 #c1 #e1 #g1 are1 !n1 z #ie to #ah1 to #cj1 to #da4 ,if ! deflections _h be5 /rictly proportionate to ! int5sities ( light /imulus !y w\ld h be5 z #ie to #bhe1 to #dge1 to #ffe4 ,illu/ration3 ,,fig4#ajd4--;,,curves ,,giv+ ,,! ,,relation ,,betwe5 ,,int5sity ,,( ,,light ,,& ,,magnitude ,,( ,,response ,9 7a7 s5sitive cell1 7b7 9 frog's ret9a4 ,9 ano!r set ( records1 ) a diff]5t cell1 ,i obta9$ ! deflections ( #f1 #aj1 #ac1 #ae1 correspond+ to light int5sities ( #c1 #e1 #g1 & #i4 ,! two curves 9 fig4#ajd1 giv+ ! relation betwe5 response & /imulus1 %[ t 9 ! case ( inorganic sub/ances1 z 9 ! ret9a 7,wall]71 magnitude ( response does n increase s rapidly z /imulus4 ,aft]-oscillation4--,:5 ! s5sitive surface is subject$ to ! cont9u$ action ( light1 ! ,e4,m4 effect atta9s a maximum at :i* x rema9s con/ant = "s "t4 ,if ! exposure be ma9ta9$ aft] ?is = a long] p]iod1 !re w be a decl9e1 z we f\nd to be ! case 9 o!r in/ances ( cont9u$ /imulation4 ,! appe>ance ( ?is decl9e1 & its rapidity1 dep5ds on ! p>ticul> condition ( ! sub/ance4 ,:5 ! s5sitive elem5t is consid]ably /ra9$ by ! action ( light1 & if t light be n[ cut (f1 !re is a reb\nd t[>ds recov]y & a subsequ5t aft]-oscillation4 ,t is to say1 ! curve ( recov]y falls bel[ ! z]o po9t1 & !n sl[ly oscillates back to ! position ( equilibrium4 ,we h already se5 an in/ance ( ?is 9 fig4#ajb4 ,above is giv5 a s]ies ( records %[+ ! appe>ance ( decl9e1 f too long-cont9u$ exposure & recov]y1 foll[$ by aft]-oscillation on ! cessation ( light 7fig4#aje74 ,c]ta9 visual analogues to ?is ph5om5on w be notic$ lat]4 ,illu/ration3 ,,fig4#aje4--;,,aft]-,,oscillation ,exposure ( "o m9ute foll[$ by obscurity ( "o m9ute4 ,note ! decl9e dur+ illum9ation1 & aft]-oscillation 9 d>kness4 ,abnormal effects4--,we h already treat$ ( all ! normal effects ( ! /imulus ( light on ! ret9a1 & _! c\nt]p>ts 9 ! s5sitive cell4 ,b ! ret9a und]goes molecul> *anges :5 injur$1 /ale1 or 9 a dy+ condition1 & "u ^! circum/ances v>i\s complicat$ modifications are obs]v$ 9 ! response4 ,illu/ration3 ,,fig4#ajf4--,,transi5t ,,positive ,,augm5tation ,,giv5 ,,by ,,! ,,frog',s ,,ret9a ,,on ,,! ,,cessation ,,( ,,light ,l 7,,wall]7 #a4 ,prelim9>y negative twit*4--,:5 ! light is incid5t on ! frog's ret9a1 !re is sometimes a transitory negative v>iation1 foll[$ by ! normal positive response4 ,?is is frequ5tly obs]v$ 9 ! s5sitive cell 7see fig4#if1 b74 #b4 ,rev]sal ( response4--,aga91 9 a /ale ret9a1 ow+ to molecul> modification ! response is apt to und]go rev]sal 7,wall]74 ,t is to say1 x n[ becomes negative4 ,9 work+ ) ! same s5sitive cell on diff]5t days ,i h f\nd x occasionally exhibit+ ?is rev]s$ response4 #c4 ,transi5t rise ( curr5t on cessation ( light4--,ano!r v curi\s fact obs]v$ 9 ! ret9a by ,kuhne & ,/e9] is t imm$iately on ! /oppage ( light !re is sometimes a sudd5 increase 9 ! ret9al curr5t1 be=e ! usual recov]y takes place4 ,?is is v well %[n 9 ! s]ies ( records tak5 by ,wall] 7fig4#ajf74 ,x w be notic$ t on illum9ation ! response-curve rises1 t cont9u$ illum9ation produces a decl9e1 & t on ! cessation ( light !re is a transi5t rise ( curr5t4 ,i give "h a s]ies ( records :i* w %[ ! rem>kable simil>ity betwe5 ! responses ( ! cell & ret9a1 9 respect ev5 ( abnormalities s m>k$ z ^? describ$ 7fig4#ajg74 ,i may m5tion "h t "s ( ^! curi\s effects1 t is to say1 ! prelim9>y negative twit* & sudd5 augm5tation ( ! curr5t on ! cessation ( light1 h also be5 notic$ by ,m9*9 9 photo-electric cells4 ,illu/ration3 ,,fig4#ajg4--,,responses ,,9 ,,silv] ,,cell ,! ?ick l9e repres5ts response dur+ light 7half a m9ute's exposure71 & dott$ l9e ! recov]y dur+ d>kness4 ,note ! t]m9al positive twit*4 #d4 ,decl9e & rev]sal4--,we h se5 t "u ! cont9u\s action ( light1 response beg9s to decl9e4 ,sometimes ?is process is v rapid1 & 9 any case1 "u cont9u$ light1 ! deflection falls4 7#a7 ,! decl9e may ne>ly rea* z]o4 ,if n[ ! light be cut (f !re is a reb\nd t[>ds recov]y d[nw>ds1 :i* c>ries x bel[ z]o1 foll[$ by an aft]-oscillation 7fig4#ajh1 a74 ,illu/ration3 ,,fig4#ajh--;,,decl9e ,,"u ,,! ,,cont9u$ ,,action ,,( ,,light 7a7 ,decl9e %ort ( z]o2 on /oppage ( light1 reb\nd d[nw>ds to z]o2 aft]-oscillation4 7b7 ,decl9e bel[ z]o2 on /oppage ( light1 reb\nd t[>ds z]o1 ) prelim9>y negative twit*4 7c7 ,! same1 decl9e fur!r d[n2 negative twit* almo/ disappe>+4 7#b7 ,if ! light be cont9u$ = a long] "t1 ! decl9e goes on ev5 bel[ z]o2 t is to say1 ! response n[ becomes app>5tly negative4 ,if1 n[1 ! light be /opp$1 !re is a reb\nd upw>ds to recov]y1 )1 g5]ally speak+1 a slight prelim9>y twit* d[nw>ds 7fig4#ajh1 b1 c74 ,?is reb\nd c>ries x back1 n only to ! z]o position1 b sometimes beyond t position4 ,we h "h a p>allel to ! foll[+ obs]vation ( ,dew> & ,mc,kendrick3 ',:5 diffuse light is all[$ to imp+e on ! eye ( ! frog1 aft] x has arriv$ at a tol]ably /able condition1 ! natural ,e4,m4,f4 is 9 ! fir/ place increas$1 !n dim9i%$2 dur+ ! cont9uance ( light x is /ill sl[ly dim9i%$ to a po9t :]e x rema9s tol]ably con/ant1 & on ! removal ( light !re is a sudd5 increase ( ! ,e4,m4 p[] ne>ly up to its orig9al position4'#ah 7#c7 ,i h sometimes obta9$ ! foll[+ curi\s result4 ,on ! incid5ce ( light !re is a response1 say1 upw>d4 ,on ! cont9uation ( light ! response decl9es to z]o & rema9s at ! z]o position1 !re be+ no fur!r action dur+ ! cont9uation ( /imulus4 ,b on ! cessation or 'break' ( light /imulus1 !re is a response d[nw>ds1 foll[$ by ! usual recov]y4 ,?is rem9ds u ( a some:at simil> responsive action produc$ by con/ant electric curr5t on ! muscle4 ,at ! mom5t ( 'make' !re is a responsive twit*1 b aft]w>ds ! muscle rema9s quiesc5t dur+ ! passage ( ! curr5t1 b on break+ ! curr5t !re is se5 a second responsive twit*4 ,rsum4--,s we see t ! response ( ! s5sitive inorganic cell1 to ! /imulus ( light1 is 9 e way simil> to t ( ! ret9a4 ,9 bo? we h1 "u normal conditions1 a positive v>iation2 9 bo? ! int5sity ( response up to a c]ta9 limit increases ) ! duration ( illum9ation2 x is affect$1 9 bo? alike1 by temp]ature2 9 bo? !re is comp>atively little fatigue2 ! increase ( response ) int5sity ( /imulus is simil> 9 bo?2 & f9ally1 ev5 9 abnormalities--su* z rev]sal ( response1 prelim9>y negative twit* on comm5cem5t1 & t]m9al positive twit* on cessation ( illum9ation1 & decl9e & rev]sal "u cont9u$ action ( light--p>allel effects are notic$4 ,illu/ration3 ,,fig4#aji4--;,,c]ta9 ,,aft]-,,effects ,,( ,,light ,we may notice "h c]ta9 curi\s relations ev5 9 ^! abnormal responses 7fig4#aji74 ,if ! equilibrium position rema9 always con/ant1 !n x is easy to und]/& h[1 :5 ! ris+ curve has atta9$ its maximum1 on ! cessation ( light1 recov]y %\ld proce$ d[nw>ds1 t[>ds ! equilibrium position 7fig4#aji1 a74 ,"o c also und]/& h[1 aft] rev]sal by ! cont9u$ action ( light1 !re %\ld be a recov]y upw>ds t[>ds ! old equilibrium position 7fig4#aji1 b74 ,:at is curi\s is t 9 c]ta9 cases we get1 on ! /oppage ( light1 a prelim9>y twit* away f ! z]o or equilibrium position1 upw>ds z 9 7c7 7comp>e also fig4#ajg7 & d[nw>ds z 9 7d7 7comp>e also fig4#ajh b74 ,9 mak+ a g5]al retrospect1 f9ally1 ( ! effects produc$ by /imulus ( light1 we f9d t !re is n a s+le ph5om5on 9 ! responses1 normal or abnormal1 exhibit$ by ! ret9a :i* has n its c\nt]p>t 9 ! s5sitive cell con/ruct$ ( inorganic mat]ial4 ,,footnotes3 #ah ,proc4 ,roy4 ,soc4 ,ed941 #ahgc p4#aec4 ,,*apt] ,,xix ,,visual ,,analogues ,effect ( light ( %ort duration--,aft]-oscillation--,positive & negative aft]-images--,b9ocul> alt]nation ( vision--,p]iod ( alt]nation modifi$ by physical condition--,aft]-images & _! revival--,unconsci\s visual impression4 ,we h already ref]r$ to ! electrical !ory ( ! visual impulse4 ,we h se5 h[ a fla% ( light causes a transitory electric impulse n only 9 ! ret9a1 b also 9 its inorganic sub/itute4 ,light ?us produces n only a visual b also an electrical impulse1 & x is n improbable t ! two may be id5tical4 ,aga91 v>y+ int5sities ( light give rise to correspond+ int5sities ( curr5t1 & ! curves :i* repres5t ! relation betwe5 ! increas+ /imulus & ! increas+ response h a g5]al agreem5t ) ! correspond+ curve ( visual s5sation4 ,9 ! pres5t *apt] we %all see h[ ?is electrical !ory n only expla9s 9 a simple mann] ord9>y visual ph5om5a1 b is also deeply sugge/ive ) reg>d to o!rs :i* are v obscure4 ,we h se5 9 our silv] cell t if ! molecul> conditions ( ! ant]ior & po/]ior surfaces 7 exactly simil>1 !re w\ld be no curr5t4 ,9 practice1 h[ev]1 ?is is seldom ! case4 ,!re is1 g5]ally speak+1 a slight diff]5ce1 & a feeble curr5t 9 ! circuit4 ,x is ?us se5 t !re may be an exi/+ feeble curr5t1 to :i* ! effect ( light is add$ algebraically4 ,! /imulus ( light may ?us increase ! exi/+ curr5t ( d>kness 7positive v>iation74 ,on ! cessation ( light aga91 ! curr5t ( response disappe>s & !re rema9s only ! feeble orig9al curr5t4 ,9 ! case ( ! ret9a1 also1 x is curi\s to note t on clos+ ! eye ! s5sation is n "o ( absolute d>kness1 b !re is a g5]al feeble s5sation ( light1 kn[n z '! intr9sic light ( ! ret9a4' ,! effect produc$ by ext]nal light is sup]pos$ on ?is intr9sic light1 & c]ta9 curi\s results ( ?is algebraical summation w be notic$ lat]4 ,illu/ration3 ,,fig4#aaj--,,response-,,curves ,,( ,,! ,,s5sitive ,,silv] ,,cell ,%[+ great] p]si/5ce ( aft]-effect :5 ! /imulus is /rong4 7a7 ,%ort exposure ( #b to light ( int5sity #a2 7b7 %ort exposure ( #b to light n9e times z /rong4 ,effect ( light ( %ort duration4--,if we subject ! s5sitive cell to a fla% ( radiation1 ! effect is n in/antane\s b gr[s ) "t4 ,x atta9s a maximum "s little "t aft] ! incid5ce ( light1 & ! effect !n gradually passes away4 ,aga91 z we h se5 previ\sly ) reg>d to me*anical /ra91 ! aft]-effect p]si/s = a slightly long] "t :5 ! /imulus is /rong]4 ,! same is true ( ! aft]-effect ( ! /imulus ( light4 ,two curves :i* exhibit ?is are giv5 bel[ 7fig4#aaj74 ,) reg>d to ! fir/ po9t--t ! maximum effect is atta9$ "s "t aft] ! cessation ( a %ort exposure--! correspond+ exp]im5t on ! eye may be made z foll[s3 at ! end ( a tube is fix$ a glass disc coat$ ) lampblack1 on :i*1 by scrat*+ ) a p91 "s words are writt5 9 transp>5t *>act]s4 ,! l5g? ( ! tube is s adju/$ t ! disc is at ! di/ance ( mo/ di/9ct vision f ! end ( ! tube appli$ to ! eye4 ,! black5$ disc is turn$ t[>ds a s\rce ( /rong light1 & a %ort exposure is giv5 by ! release ( a photographic %utt] int]pos$ betwe5 ! disc & ! eye4 ,on clos+ ! eye1 imm$iately aft] a %ort exposure1 x w at fir/ be f\nd t !re is h>dly any well-def9$ visual s5sation2 aft] a %ort "t1 h[ev]1 ! writ+ on ! black5$ disc beg9s to appe> 9 lum9\s *>act]s1 atta9s a maximum int5sity1 & !n fades away4 ,9 ?is case ! /imulus is ( %ort duration1 ! light be+ cut (f be=e ! maximum effect is atta9$4 ,! aft]-effect "h is positive1 !re be+ no rev]sal or int]val ( d>kness betwe5 ! direct image & ! aft]-image1 ! "o be+ m]ely ! cont9uation ( ! o!r4 ,b we %all see1 if light is cut (f aft] a maximum effect is atta9$ by long exposure1 t ! imm$iate aft]-image w\ld be negative 7see bel[74 ,! relative p]si/5ce ( aft]-effect ( lights ( diff]5t int5sities may be %[n 9 ! foll[+ mann]3 ,if a bold design be trac$ ) magnesium p[d] on a black5$ bo>d & fir$ 9 a d>k room1 ! obs]v] n be+ acqua9t$ ) ! design1 ! in/antane\s fla% ( light1 besides be+ too quick = detail$ obs]vation1 is obscur$ by ! accompany+ smoke4 ,b if ! eyes be clos$ imm$iately aft] ! fla%1 ! feebl] obscur+ s5sation ( smoke w fir/ disappe>1 & w leave cle> ! m p]si/5t aft]-s5sation ( ! design1 :i* c !n be read di/9ctly4 ,9 ?is mann] ,i h (t5 be5 able to see di/9ctly1 on clos+ ! eyes1 extremely brief ph5om5a ( light :i* c\ld n o!rwise h be5 obs]v$1 ow+ ei!r to _! excessive rapidity or to _! dazzl+ "*4#ai ,aft]-oscillation4--,9 ! case ( ! s5sitive silv] cell1 we h se5 7fig4#aje71 :5 x has be5 subject$ = "s "t to /rong light1 t ! curr5t ( response atta9s a maximum1 & t on ! /oppage ( ! /imulus !re is an imm$iate reb\nd t[>ds recov]y4 ,9 ?is reb\nd !re may be an ov]-%oot+ ( ! equilibrium position1 & an aft]-oscillation is ?us produc$4 ,if !re has be5 a feeble initial curr5t1 ?is oscillatory aft]-curr5t1 by algebraical summation1 w cause ! curr5t 9 ! circuit to be alt]nately weak] & /rong] ?an ! initial curr5t4 ,visual recurr5ce4--,translat$ into ! visual circuit1 ?is w\ld mean an alt]nat+ s]ies ( aft]-images4 ,on ! cessation ( light ( /rong int5sity & long duration1 ! imm$iate effect w\ld be a negative reb\nd1 unlike ! positive aft]-effect :i* foll[$ on a %ort exposure4 ,! next reb\nd is positive1 giv+ rise to a s5sation ( brightness4 ,?is w g on 9 a recurr5t s]ies4 ,if we look = "s "t at a v bright object1 pref]ably ) "o eye1 on clos+ ! eye !re is an imm$iate d>k s5sation foll[$ by a s5sation ( light4 ,^! g on alt]nat+ & give rise to ! ph5om5a ( recurr5t vision4 ,) ! eyes clos$1 ! positive or lum9\s phases are ! m prom95t4 ,?is ph5om5on may be obs]v$ 9 a some:at diff]5t mann]4 ,aft] />+ at a bright light we may look t[>ds a well-light$ wall4 ,! d>k phases w n[ become ! m noticeable4 ,if1 h[ev]1 we look t[>ds a dimly light$ wall1 bo? ! d>k & bright phases w be notic$ alt]nately4 ,! negative effect is usually expla9$ z due to fatigue4 ,t position ( ! ret9a affect$ by light is suppos$ to be 'tir$1' & a negative image to be =m$ 9 consequ5ce ( exhau/ion4 ,by ?is exhau/ion is meant ei!r ! pres5ce ( fatigue-/uffs1 or ! break+-d[n ( ! s5sitive elem5t ( ! tissue1 or bo? ( ^!4 ,9 su* a case we %\ld expect t ?is fatigue1 ) its consequ5t negative image1 w\ld gradually & f9ally disappe> on ! re/oration ( ! ret9a to its normal condition4 ,we f9d1 h[ev]1 t ?is is n ! case1 = ! negative image recurs ) alt]nate positive4 ,! accept$ !ory ( fatigue is incapable ( expla9+ ?is ph5om5on4 ,9 ! s5sitive silv] cell1 we f\nd t ! molecul> /ra9 produc$ by light gave rise to a curr5t ( response1 & t on ! cessation ( light an oscillatory aft]-effect 0 produc$4 ,! alt]nat+ aft]-effect 9 ! ret9a po9ts to an exactly simil> process4 ,b9ocul> alt]nation ( vision4--,x 0 :ile exp]im5t+ on ! ph5om5a ( recurr5t vision t ,i discov]$ ! curi\s fact t 9 normal eyes ! two d n see equally well at a giv5 in/ant1 b t ! visual effect 9 ea* eye und]goes fluctuation f mom5t to mom5t1 9 su* a way t ! s5sation 9 ! "o is complem5t>y to t 9 ! o!r1 ! sum ( ! two s5sations rema9+ approximately con/ant4 ,?us !y take up ! "w ( see+1 & !n1 relatively speak+1 re/+1 alt]nately4 ,?is division ( lab\r1 9 b9ocul> vision1 is ( obvi\s advantage4 ,z reg>ds maximum s5sation 9 ! two ret9 !re is !n a relative ret>dation ( half a p]iod4 ,?is may be se5 by means ( a /]eoscope1 c>ry+1 in/ead ( /]eo-photographs1 incis$ plates ?r\gh :i* we look at light4 ,! design consi/s ( two slant+ cuts at a suitable di/ance f ea* o!r4 ,"o cut1 ,r1 slants to ! "r1 & ! o!r1 ,l1 to ! left 7see fig4#aaa74 ,:5 ! design is look$ at ?r\gh ! /]eoscope1 ! "r eye w see1 say ,r1 & ! left ,l1 ! two images w appe> sup]impos$1 & we see an incl9$ cross4 ,:5 ! /]eoscope is turn$ t[>ds ! sky1 & ! cross look$ at /eadily = "s "t1 x w be f\nd1 ow+ to ! alt]nation already ref]r$ to1 t :ile "o arm ( ! cross beg9s to be dim1 ! o!r becomes bright1 & vice v]sa4 ,! alt]nate fluctuations become f> m conspicu\s :5 ! eyes are clos$2 ! pure oscillatory aft]-effects are !n obta9$ 9 a mo/ vivid mann]4 ,aft] look+ ?r\gh ! /]eoscope = t5 seconds or m1 ! eyes are clos$4 ,! fir/ effect obs]v$ is "o ( d>kness1 due to ! reb\nd4 ,!n "o lum9\s arm ( ! cross fir/ projects aslant ! d>k field1 & !n sl[ly disappe>s1 aft] :i* ! second 7p]ceiv$ by ! o!r eye7 %oots out sudd5ly 9 a direction a?w>t ! fir/4 ,?is alt]nation proce$s = a long "t1 & produces ! curi\s effect ( two lum9\s blades cross+ & recross+ ea* o!r4 ,illu/ration3 ,,fig4#aaa4--,,/]eoscopic ,,design ,ano!r me?od ( br++ out ! ph5om5on ( alt]nation 9 a /ill m /rik+ mann] is to look at two diff]5t sets ( writ+1 ) ! two eyes4 ,! resultant effect is a blur1 due to sup]position1 & ! inscription _c be read ) ! eyes op54 ,b on clos+ !m1 ! composite image is analys$ alt]nately into its compon5t p>ts1 & ?us we are enabl$ to read bett] ) eyes %ut ?an op54 ,?is p]iod ( alt]nation is modifi$ by age & by ! condition ( ! eye4 ,x is1 g5]ally speak+1 %ort] 9 y\?4 ,i h se5 x v>y 9 diff]5t individuals f #a to #aj or m4 ,ab\t #d is ! mo/ usual4 ,) ! same individual1 aga91 ! p]iod is some:at modifi$ by previ\s conditions ( re/ or activity4 ,v e>ly 9 ! morn+1 aft] sleep1 x is at its %orte/4 ,i give bel[ a set ( read+s giv5 by an obs]v]3 ,p]iod #h ,a4,m4 #c #ab noon #d #c ,p4,m4 #e #f ,p4,m4 #ed #i #ef #aa #fe ,aga91 if "o eye be cool$ & ! o!r w>m$1 ! ret9al oscillation 9 "o eye is quick] ?an 9 ! o!r4 ,! quick] oscillation ov]takes ! sl[]1 & we obta9 ! curi\s ph5om5on ( 'visual beats4' ,aft]-images & _! revival4--,9 ! exp]im5t ) ! /]eoscope & ! design ( ! cross1 ! aft]-images ( ! cross se5 ) ! eyes clos$ are at fir/ v di/9ct--s di/9ct t any unev5ness at ! edges ( ! slant+ cuts 9 ! design c be di/9ctly made out4 ,!re c ?us be no d\bt ( ! 'objective' nature ( ! /ra9 impression on ! ret9a1 :i* on ! cessation ( direct /imulus ( light gives rise to aft]-oscillation ) ! concomitant visual recurr5ce4 ,?is recurr5ce may !re=e be tak5 z a pro( ( ! physical /ra9 produc$ on ! ret9a4 ,! recurr5t aft]-image is v di/9ct at ! beg9n+ & becomes fa9t] at ea* repetition2 a "t comes :5 x is difficult to tell :e!r ! image se5 is ! objective aft]-effect due to /ra9 or m]ely an effect ( 'memory4' ,9 fact !re is no l9e ( dem>cation betwe5 ! two1 "o simply m]ges into ! o!r4 ,t ?is 'memory' image is due to objective /ra9 is r5d]$ evid5t by its recurr5ce4 ,9 connection ) ?is x is int]e/+ to note t "s ( ! und\bt$ ph5om5a ( memory are also recurr5t4 ',c]ta9 s5sations = :i* !re is no correspond+ process outside ! body are g5]ally gr\p$ = conv5i5ce "u ?is t]m memory4 ,if ! eyes be clos$ & a picture be call$ to memory1 x w be f\nd t ! picture _c be held1 b w repeat$ly disappe> & appe>4'#bj ,! visual impressions & _! recurr5ce (t5 p]si/ = a v long "t4 ,x usually happ5s t ow+ to we>9ess ! recurr5t images disappe>2 b 9 "s in/ances1 long aft] ?is disappe>ance1 !y w spontane\sly reappe> at mo/ unexpect$ mom5ts4 ,9 "o in/ance ! recurr5ce 0 obs]v$ 9 a dream1 ab\t ?ree weeks aft] ! orig9al impression 0 made4 ,9 connection ) ?is1 ! revival ( images1 on clos+ ! eyes at night1 t h be5 se5 dur+ ! day1 is extremely int]e/+4 ,unconsci\s visual impression4--,:ile repeat+ c]ta9 exp]im5ts on recurr5t vision1 ! above ph5om5on became prom95t 9 an unexpect$ mann]4 ,i _h be5 int5tly look+ at a p>ticul> w9d[1 & obta9+ ! subsequ5t aft]-images by clos+ ! eye2 my att5tion 0 conc5trat$ on ! w9d[1 & ,i saw no?+ b ! w9d[ ei!r z a direct or z an aft] effect4 ,aft] ?is _h be5 repeat$ a numb] ( times1 ,i f\nd on "o occasion1 aft] clos+ ! eye1 t1 ow+ to we>9ess ( ! p>ticul> portion ( ! ret9a1 ,i c\ld no long] see ! aft]-image ( ! w9d[2 in/ead ( ?is ,i h[ev] saw di/9ctly a circul> op5+ clos$ ) glass panes1 & ,i notic$ ev5 ! jagg$ edges ( a brok5 pane4 ,i 0 n aw>e ( ! exi/5ce ( a circul> op5+ high] up 9 ! wall4 ,! image ( ?is _h impress$ itself on ! ret9a )\t my k1 & _h und\bt$ly be5 produc+ ! recurr5t images :i* rema9$ unnotic$ because my pr9cipal field ( aft]-vision 0 fill$ up & my att5tion direct$ t[>ds ! recurr5t image ( ! w9d[4 ,:5 ?is fail$ to appe>1 my field ( aft]-vision 0 relatively free f di/raction1 & ,i c\ld n help see+ :at 0 unnotic$ be=e4 ,x ?us appe>s t1 9 addition to ! images impress$ 9 ! ret9a ( :i* we are consci\s1 !re are _m o!rs :i* are impr9t$ )\t our k4 ,we fail to notice !m because our att5tion is direct$ to some?+ else4 ,b at a subsequ5t p]iod1 :5 ! m9d is 9 a passive /ate1 ^! impressions may sudd5ly revive ow+ to ! ph5om5on ( recurr5ce4 ,?is obs]vation may af=d an explanation ( "s ( ! ph5om5a connect$ ) ocul> phantoms & halluc9ations n traceable to any disease4 ,9 ^! cases ! psy*ical effects produc$ appe> to h no objective cause4 ,be>+ 9 m9d ! num]\s visual impressions :i* are be+ unconsci\sly made on ! ret9a1 x is n at all unlikely t _m ( ^! visual phantoms may be due to objective causes4 ,,footnotes3 #ai ,z an in/ance ( ?is ,i may m5tion ! exp]im5t :i* ,i saw on ! quick fusion ( metals exhibit$ at ! ,royal ,in/itution by ,sir ,william ,rob]ts-,au/5 7#aija71 :]e1 ow+ to ! gl>e & ! d5se fumes1 x 0 impossible to see :at happ5$ 9 ! crucible4 ,b ,i 0 able to see e detail on clos+ ! eyes4 ,! effects ( ! smoke1 be+ ( less lum9esc5ce1 cle>$ away fir/1 & left ! aft]-image ( ! molt5 metal gr[+ cle>] on ! ret9a4 #bj ,e4,w4 ,scripture1 ,! ,new ,psy*ology1 p4#aja4 ,,*apt] ,,xx ,,g5]al ,,survey ,,& ,,conclusion ,we h se5 t /imulus produces a c]ta9 excitatory *ange 9 liv+ sub/ances1 & t ! excitation produc$ sometimes expresses itself 9 a visible *ange ( =m1 z se5 9 muscle2 t 9 _m o!r cases1 h[ev]--z 9 n]ve or ret9a--!re is no visible alt]ation1 b ! di/urbance produc$ by ! /imulus exhibits itself 9 c]ta9 electrical *anges1 & t :]eas ! me*anical mode ( response is limit$ 9 its application1 ?is electrical =m is univ]sal4 ,?is irritability ( ! tissue1 z %[n 9 its capacity = response1 electrical or me*anical1 0 f\nd to dep5d on its physiological activity4 ,"u c]ta9 conditions x c\ld be conv]t$ f ! responsive to an irresponsive /ate1 ei!r tempor>ily z by an/hetics1 or p]man5tly z by poisons4 ,:5 ?us made p]man5tly irresponsive by any means1 ! tissue 0 said to h be5 kill$4 ,we h se5 fur!r t f ?is obs]v$ fact--t a tissue :5 kill$ passes out ( ! /ate ( responsiv5ess into t ( irresponsiv5ess2 & f a confusion ( 'dead' ?+s ) inanimate matt]1 x has be5 tacitly assum$ t inorganic sub/ances1 l dead animal tissues1 mu/ necess>ily be irresponsive1 or incapable ( be+ excit$ by /imulus--an assumption :i* has be5 %[n to be gratuit\s4 ,?is 'unexpla9$ conception ( irritability became ! />t+-po9t1' to quote ! words ( ,v]worn1#ba '( vitalism1 :i* 9 its mo/ complete =m ass]t$ a dualism ( liv+ & lifeless ,nature4444 ,! vitali/s soon1' z he goes on to say1 'laid aside1 m or less completely1 me*anical & *emical explanations ( vital ph5om5a1 & introduc$1 z an explanatory pr9ciple1 an all-controll+ unkn[n & inscrutable =ce hyp]mcanique4 ,:ile *emical & physical =ces are responsible = all ph5om5a 9 lifeless bodies1 9 liv+ organisms ?is special =ce induces & rules all vital actions4 ',lat] vitali/s1 h[ev]1 attempt$ no analysis ( vital =ce2 !y employ$ x 9 a :olly my/ical =m z a conv5i5t explanation ( all sorts ( vital ph5om5a4444 ,9 place ( a real explanation a simple phrase su* z vital =ce 0 satisfactory1 & signifi$ a my/ical =ce belong+ to organisms only4 ,?us x 0 easy to expla9 ! mo/ complex vital ph5om5a4' ,f ?is position1 ) its assumption ( ! sup]-physical "* ( response1 x is cle> t on ! discov]y ( simil> effects among/ inorganic sub/ances1 ! necessity ( !oretically ma9ta9+ su* dualism 9 ,nature mu/ imm$iately fall to ! gr\nd4 ,9 ! previ\s *apt]s ,i h %[n t n ! fact ( response alone1 b all ^? modifications 9 response :i* occur "u v>i\s conditions1 take place 9 plants & metals j z 9 animal tissues4 ,x may n[ be well to make a g5]al survey ( ^! ph5om5a1 z exhibit$ 9 ! ?ree classes ( sub/ances4 ,we h se5 t ! wave ( molecul> di/urbance 9 a liv+ animal tissue "u /imulus is accompani$ by a wave ( electrical di/urbance2 t 9 c]ta9 types ( tissue ! /imulat$ is relatively positive to ! less di/urb$1 :ile 9 o!rs x is ! rev]se2 t x is ess5tial to ! obta9+ ( electric response to h ! contacts lead+ to ! galvanomet] unequally affect$ by excitation2 & f9ally t ?is is accompli%$ ei!r 7#a7 by 'injur+' "o contact1 s t ! excitation produc$ !re w\ld be relatively feeble1 or 7#b7 by introduc+ a p]fect block betwe5 ! two contacts1 s t ! excitation rea*es "o & n ! o!r4 ,fur!r1 x has be5 %[n t ?is *>act]i/ic ( exhibit+ electrical response "u /imulus is n conf9$ to animal1 b ext5ds also to vegetable tissues4 ,9 ^! ! same electrical v>iations z 9 n]ve & muscle 7 obta9$1 by us+ ! me?od ( injury1 or t ( ! block4 ,pass+ to inorganic sub/ances1 & us+ simil> exp]im5tal arrangem5ts1 we h f\nd ! same electrical responses evok$ 9 metals "u /imulus4 ,negative v>iation4--,9 all cases1 animal1 vegetable1 & metal1 we may obta9 response by ! me?od ( negative v>iation1 s call$1 by r$uc+ ! excitability ( "o contact by physical or *emical means4 ,/imulus causes a transi5t dim9ution ( ! exi/+ curr5t1 ! v>iation dep5d+ on ! int5sity ( ! /imulus 7figs4 #d1 #g1 #ed74 ,illu/ration3 ,,fig4#aab4--,,uni=m ,,responses ,,9 7,a7 ,,n]ve1 7,p7 ,,plant1 ,,& 7,m7 ,,metal ,! normal response 9 n]ve is repres5t$ 'd[n4' ,9 ?is & foll[+ figures1 7,a7 is ! record ( responses 9 animal1 7,p7 9 plant1 & 7,m7 9 metal4 ,relation betwe5 /imulus & response4--,9 all ?ree classes we h f\nd t ! int5sity ( response increases ) increas+ /imulus4 ,at v high int5sities ( /imulus1 h[ev]1 !re is a t5d5cy ( ! response to rea* a limit 7figs4 #cj1 #cb1 #hd74 ,! law t is kn[n z ,web]-,fe*n]'s %[s a simil> *>act]i/ic 9 ! relation betwe5 /imulus & s5sation4 ,& if s5sation be a measure ( physiological effect we c und]/& ?is correspond5ce ( ! physiological & s5sation curves4 ,we n[ see fur!r t ! physiological effects !mselves are ultimately r$ucible to simple physical ph5om5a4 ,effects ( sup]position4--,9 all ?ree types1 ineffective /imuli become effective by sup]position4 ,aga91 rapidly succe$+ /imuli produce a maximum effect1 kept balanc$ by a =ce ( re/itution1 & cont9uation ( /imulus produces no fur!r effect1 9 ! ?ree cases alike 7figs4 #ag1 #ah1 #hf74 ,uni=m responses4--,9 ! responses ( animal1 vegetable1 & metal alike we meet ) a type :]e ! responses are uni=m 7fig4#aab74 ,fatigue4--,!re is1 aga91 ano!r type :]e fatigue is exhibit$4 ,illu/ration3 ,,fig4#aac4--;,,fatigue 7,a7 ,,9 ,,muscle1 7,p7 ,,9 ,,plant1 7,m7 ,,9 ,,metal ,! explanation hi!rto giv5 ( fatigue 9 animal tissues--t x is due to dissimilation or breakd[n ( tissue1 complicat$ by ! pres5ce ( fatigue-products1 :ile recov]y is due to assimilation1 = :i* mat]ial is br\ght by ! blood-supply--has long be5 se5 to be inadequate1 s9ce ! re/orative effect succe$s a %ort p]iod ( re/ ev5 9 excis$ bloodless muscle4 ,b t ! ph5om5a ( fatigue & recov]y 7 n prim>ily dep5d5t on dissimilation or assimilation becomes self-evid5t :5 we f9d exactly simil> effects produc$ n only 9 plants1 b also 9 metals 7fig4#aac74 ,x has be5 %[n1 on ! o!r h&1 t ^! effects are prim>ily due to cumulative residual /ra9s1 & t a brief p]iod ( re/1 by remov+ ! ov]/ra91 removes also ! sign ( fatigue4 ,/aircase effect4--,! !ory ( dissimilation due to /imulus r$uc+ ! functional activity bel[ p>1 & ?us caus+ fatigue1 is directly negativ$ by :at is kn[n z ! '/aircase' effect1 :]e successive equal /imuli produce increas+ response4 ,we saw an exactly simil> ph5om5on 9 plants & metals1 :]e successive responses to equal /imuli exhibit$ an increase1 app>5tly by a gradual removal ( molecul> sluggi%ness 7fig4#aad74 ,illu/ration3 ,,fig4#aad4--',,/aircase' ,,9 ,,muscle1 ,,plant1 ,,& ,,metal ,illu/ration3 ,,fig4#aae4--;,,increas$ ,,response ,,aft] ,,cont9u\s ,,/imulation ,,9 ,,n]ve ,,& ,,metal ,! normal response 9 animal tissue is repres5t$ 'd[n1' 9 metal 'up4' ,increas$ response aft] cont9u\s /imulation4--,an effect some:at simil>1 t is to say1 an increas$ response1 due to increas$ molecul> mobility1 is also %[n sometimes aft] cont9u\s /imulation1 n only 9 animal tissues1 b also 9 metals 7fig4#aae74 ,modifi$ response4--,9 ! case ( n]ve we saw t ! normal response1 :i* is negative1 sometimes becomes rev]s$ 9 sign1 i4e4 positive1 :5 ! specim5 is /ale4 ,9 ret9a aga9 ! normal positive response is conv]t$ into negative "u ! same conditions4 ,simil>ly1 we f\nd t a plant :5 )]+ (t5 %[s a positive in/ead ( ! usual negative response 7fig4#bh74 ,on ne>+ ! dea?-po9t1 also by subjection to extremes ( temp]ature1 ! same rev]sal ( response is occasionally obs]v$ 9 plants4 ,?is rev]sal ( response due to peculi> molecul> modification 0 also se5 9 metals4 ,illu/ration3 ,,fig4#aaf4--,,modifi$ ,,abnormal ,,response ,,9 7,a7 ,,n]ve ,,& 7,m7 ,,metal ,,conv]t$ ,,into ,,normal1 ,,aft] ,,cont9u\s ,,/imulation 7,a7 is ! record = n]ve 7record+ galvanomet] n be+ dead-beat %[s aft]-oscillation72 ! abnormal 'up' is conv]t$ into normal 'd[n' aft] cont9u\s /imulation4 7,m7 is ! record = metal1 ! abnormal 'd[n' be+ conv]t$ into normal 'up' aft] l /imulation4 ,b ^! modifi$ responses usually become normal :5 ! specim5 is subject$ to /imulation ei!r /rong or long cont9u$ 7fig4#aaf74 ,diphasic v>iation4--,a diphasic v>iation is obs]v$ 9 n]ve1 if ! wave ( molecul> di/urbance does n rea* ! two contacts at ! same mom5t1 or if ! rate ( excitation is n ! same at ! two po9ts4 ,a simil> diphasic v>iation is also obs]v$ 9 ! responses ( plants & metals 7figs4 #bf1 #fh74 ,effect ( temp]ature4--,9 animal tissues response becomes feeble at l[ temp]atures4 ,at an optimum temp]ature x rea*es its greate/ amplitude1 &1 aga91 beyond a maximum temp]ature x is v mu* r$uc$4 ,we h obs]v$ ! same ph5om5a 9 plants4 ,9 metals too1 at high temp]atures1 ! response is v mu* dim9i%$ 7figs4 #ch1 #fe74 ,effect ( *emical reag5ts4--,f9ally1 j z ! response ( animal tissue is exalt$ by /imulants1 l[]$ by depressants1 & aboli%$ by poisons1 s also we h f\nd ! response 9 plants & metals und]go+ simil> exaltation1 depression1 or abolition4 ,we h se5 t ! crit]ion by :i* vital response is diff]5tiat$ is its abolition by ! action ( c]ta9 reag5ts--! s-call$ poisons4 ,we f9d1 h[ev]1 t 'poisons' also aboli% ! responses 9 plants & metals 7fig4#aag74 ,j z animal tissues pass f a /ate ( responsiv5ess :ile liv+ to a /ate ( irresponsiv5ess :5 kill$ by poisons1 s also we f9d metals trans=m$ f a responsive to an irresponsive condition by ! action ( simil> 'poison\s' reag5ts4 ,! p>allel is ! m /rik+ s9ce x has long be5 kn[n ) reg>d to animal tissues t ! same drug1 adm9i/]$ 9 l>ge or small doses1 might h opposite effects1 & 9 prec$+ *apt]s we h se5 t ! same /atem5t holds good ( plants & metals also4 ,/imulus ( light4--,ev5 ! responses ( su* a highly specialis$ organ z ! ret9a are /rictly p>allel$ by inorganic responses4 ,we h se5 h[ ! /imulus ( light evokes 9 ! artificial ret9a responses :i* co9cide 9 all _! detail ) ^? produc$ 9 ! real ret9a4 ,?is 0 se5 9 ineffective /imuli becom+ effective aft] repetition1 9 ! relation betwe5 /imulus & response1 & 9 ! effects produc$ by temp]ature2 also 9 ! ph5om5on ( aft]-oscillation4 ,^! simil>ities w5t ev5 fur!r1 ! v abnormalities ( ret9al response f9d+ _! reflection 9 ! inorganic4 ,illu/ration3 ,,fig4#aag4--;,,abolition ,,( ,,response ,,9 ,,n]ve1 ,,plant1 ,,& ,,metal ,,by ,,! ,,action ,,( ,,! ,,same ',,poison' ,! fir/ half 9 ea* set %[s ! normal response1 ! second half ! abolition ( response aft] ! application ( ! reag5t4 ,?us liv+ response 9 all its div]se manife/ations is f\nd to be only a repetition ( responses se5 9 ! inorganic4 ,!re is 9 x no elem5t ( my/]y or caprice1 su* z we mu/ admit to be appli$ 9 ! assumption ( a hyp]me*anical vital =ce1 act+ 9 contradiction or defiance ( ^? physical laws t gov]n ! _w ( matt]4 ,n[h]e 9 ! entire range ( ^! response-ph5om5a--inclusive z t is ( metals1 plants1 & animals--d we detect any brea* ( cont9uity4 ,9 ! /udy ( processes app>5tly s complex z ^? ( irritability1 we mu/1 ( c\rse1 expect to be confront$ ) _m difficulties4 ,b if ^! are to be ov]come1 !y1 l o!rs1 mu/ be fac$1 & _! inve/igation pati5tly pursu$1 )\t ! po/ulation ( special =ces ^: conv5i5t prop]ty x is to meet all em]g5cies 9 virtue ( _! vagu5ess4 ,if1 at lea/1 we are ev] to und]/& ! intricate me*anism ( ! animal ma*9e1 x w be grant$ t we mu/ cease to evade ! problems x pres5ts by ! use ( m]e phrases :i* really expla9 no?+4 ,we h se5 t among/ ! ph5om5a ( response1 !re is no necessity = ! assumption ( vital =ce4 ,!y are1 on ! contr>y1 physico-*emical ph5om5a1 susceptible ( a physical inquiry z def9ite z any o!r 9 inorganic regions4 ,physiologi/s h taught u to read 9 ! response-curves a hi/ory ( ! influ5ce ( v>i\s ext]nal ag5cies & conditions on ! ph5om5on ( life4 ,by ^! means we are able to trace ! gradual dim9ution ( responsiv5ess by fatigue1 by extremes ( heat & cold1 its exaltation by /imulants1 ! arre/ ( ! life-process by poison4 ,! inve/igations :i* h j be5 describ$ may possibly c>ry u "o /ep fur!r1 prov+ to u t ^! ?+s are det]m9$1 n by ! play ( an unkn[able & arbitr>y vital =ce1 b by ! work+ ( laws t "k no *ange1 act+ equally & uni=mly ?r\gh\t ! organic & ! inorganic worlds4 ,,footnotes3 #ba ,v]worn1 ,g5]al ,physiology1 p4#ah4 ,,index ,action curr5t 9 metal1 #hh 9 n]ve1 #h 9 plant1 #ai ,aft]-images & _! revival1 #agg ,aft]-oscillation 9 photo-s5sitive cell1 #aei1 #afc ,an/hetics1 effect on response 9 n]ve1 #gb 9 plant1 #cj1 #gc1 #gd1 #ge ,anneal+1 effect on response 9 metal1 #aja1 #ach ,b9ocul> alt]nation ( vision1 #age ,block me?od1 advantages (1 #bh1 #gg = obta9+ response 9 metal1 #hb 9 plant1 #bh ,*loral1 effect on plant response1 #ge ,*lor(orm1 effect on n]ve response1 #gb plant response1 #gd ,comp5sator1 #bb ,curr5t ( injury 9 n]ve1 #g ,curves1 *>act]i/ics ( response1 #c ,dea?-po9t1 det]m9ation (1 9 plants1 #fa1 #fc ,depressants1 effect on inorganic response1 #adb ,depression1 response by relative1 #hg ,dew> on ret9al curr5t1 #adi ,diphasic v>iation 9 metal1 #aac1 #aad1 #aae1 #aaf1 #ahh 9 n]ve1 #ahh 9 plant1 #df1 #ahh ,dose1 effect on inorganic response1 #hi1 #adf1 #ahi plant response1 #gi1 #ahi ,electrical record]1 #aa ,electrical response4 ,see ,response1 electrical ,electric tapp]1 #bd ,exaltation1 response by relative1 #hi ,fatigue1 abs5ce (1 "u c]ta9 conditions1 9 metal1 #abj 9 muscle1 #ci 9 plant1 #ci app>5t1 ) increas$ frequ5cy ( /imulation1 9 metal1 #abj 9 muscle1 #dj 9 plant1 #dj dim9ution ( response "u /rong /imulus due to1 9 plant1 #eg 9 metal1 #aah1 #aai1 #ahe 9 muscle1 #aah1 #ahe 9 plant1 #bj1 #ahe due to ov]/ra91 #da rapid1 "u cont9u\s /imulation 9 metal1 #aba1 #acj 9 muscle1 #db1 #acj 9 plant1 #db1 #acj removal (1 by re/ 9 plant1 #dc !ory (1 9 muscle1 #ch1 #ahe ,holmgr5 on ret9al curr5t1 #adi ,hy/]esis1 #acg ,injury1 curr5t (1 9 n]ve1 #g ,inorganic response4 ,see ,metal1 electrical response 9 ,kuhne on ret9al curr5t1 #adi ,kunkel on electrical *anges by injury or flexion 9 plant1 #ad1 #gj ,light1 aft]-effect ( %ort exposure to1 on photo-s5sitive cell1 #aga on ret9a1 #aga decl9e & rev]sal ( response "u cont9u\s1 9 photo-s5sitive cell1 #aff 9 ret9a #aff effect ( temp]ature on response ( photo-s5sitive cell produc$ by1 #aeh ret9al response produc$ by1 #aeh relation betwe5 int5sity & response to1 9 photo-s5sitive cell1 #afa1 #afb 9 ret9a1 #afb response to1 aft]-oscillation 9 photo-s5sitive cell1 #aei1 #afc effect ( increas+ l5g? ( exposure 9 photo-s5sitive cell1 #aei 9 ret9a1 #afj 9 frog's ret9a1 #aej1 #aea1 #aef1 #afd1 #aff 9 photo-s5sitive cell1 #aeb1 #aec1 #aed1 #aee1 #aeg1 #afe1 #aff ,mc,kendrick on ret9al response1 #adi ,me*anical record]1 #c response1 #a /imulus by electric tapp]1 #bd by spr+-tapp]1 #bc by vibrator1 #bd conditions ( ma9ta9+ uni=mity (1 #bf means ( graduat+ int5sity (1 #bb1 #bd1 #if ,metal1 electric response 91 abnormal1 #abe abolition (1 by 'poison1' #adc additive effect ( sup]position ( /imulus on1 #ace anneal+1 effect (1 on1 #aja by me?od ( block1 #hb1 #ib negative v>iation1 #hg1 #ahc depressants1 effect (1 on1 #adb diphasic1 #aac1 #aad1 #aae1 #aaf1 #ahh enhancem5t (1 aft] cont9u\s /imulation1 #abg1 #abh1 #ahf fatigue1 #aah1 #aai1 #abj1 #aba1 #ahe4 ,see also ,fatigue maximum effect due to sup]position ( /imuli1 #acf modifi$1 #abi 'molecul> arre/1' effect (1 by 'poison' on1 #ade molecul> friction1 effect (1 on1 #ajh1 #aji prolongation ( recov]y by ov]/ra91 #ajf by 'poison1' #ade relation betwe51 & /imulus1 #acd1 #ace /aircase effect1 #abb1 #ahf /imulant1 effect (1 on1 #ada temp]ature1 effect (1 on1 #aaa uni=m1 #ajb1 #ahd ,m9*9 on photo-electric cell1 #afe ,molecul> 'arre/' 9 metals by 'poison1' #ade friction1 #ajh1 #aji model1 #ajg voltaic cell1 #ii ,munck on electric response 9 s5sitive plants1 #ad ,muscle1 fatigue 91 #ch1 #ci1 #dj1 #db4 ,see also ,fatigue prolongation ( recov]y by 'poison' 91 #add relation betwe5 /imulus & response 91 #eb /aircase effect 91 #abb /imulus1 effect ( sup]position (1 on1 #cf ,myograph1 #b ,negative v>iation1 response by me?od (1 9 metal1 #hg1 #ahc 9 n]ve1 #i1 #ahc 9 plant1 #ah1 #ahc ,n]ve1 curr5t ( injury 91 #g injur$ & un9jur$ contacts correspond+ to ,cu & ,zn 9 voltaic c\ple1 #h response 91 abnormal1 :5 /ale1 #abd1 #ahg abolition (1 by 'poison1' #aci1 #ahi an/hetics1 effect (1 on1 #gb by me?od ( negative v>iation1 #i curr5t ( action (1 #h enhancem5t (1 aft] cont9u\s /imulation1 #abg modifi$1 #abh relation betwe51 & /imulus1 #eb rev]s$ :5 /ale1 #aa uni=m1 #ahd ,nom5clature1 anomalies ( pres5t1 #i1 #he ,photographic record]1 #aa1 #bb ,plant *amb]1 #fd electrical response 91 abnormal1 :5 /ale or dy+1 #dh1 #ahg abolition (1 by high temp]ature1 #cb1 #fd additive effect ( /imulus on1 #cg an/hetics1 effect (1 on1 #cj1 #gc1 #gd1 #ge by me?od ( block1 #bh ( negative v>iation1 #ah1 #ahc diphasic1 #df fatigue1 #bj1 #ci1 #dj1 #da1 #db1 #dc1 #eg1 #ahe4 ,see also ,fatigue physiological "*1 #cj 'poison1' effect (1 on1 #cj1 #cb1 #gh1 #gi relation betwe51 & /imulus1 #eb1 #ec1 #ed /aircase effect1 #cg1 #ahe /imulus1 effect ( s+le1 on1 #ce effect ( sup]position (1 on1 #ce temp]ature1 effect (1 on1 #cb1 #ei-fi uni=m1 #cf1 #ahd radial ,e4,m4 response 91 #di ,poison1 effect (1 on response 9 metal1 #adc1 #ahi 9 n]ve1 #aci1 #ahi 9 plant1 #cj1 #cb1 #gh1 #gi1 #ahi 'molecul> arre/' 9 metal by1 #ade prolongation ( recov]y by action (1 9 metal1 #ade 9 muscle1 #add ,record1 simultane\s me*anical & electrical1 ( response1 #ac ,record]1 electrical1 #aa me*anical1 #c photographic1 #aa1 #bb response1 #ai ,response-curve1 *>act]i/ics (1 #c electrical1 abnormal1 9 metal1 #abc1 #abe 9 /ale n]ve1 #aa1 #abc 9 /ale or dy+ plant1 #dh1 #ahg 9 /ale ret9a1 #aa1 #afd conv]t$ into normal aft] /rong or cont9u\s /imulation 9 metal1 #abe1 #ahg 9 n]ve1 #abd1 #ahg 9 plant1 #dh abolition (1 by high temp]ature 9 plant1 #cb1 #fd by 'poison1' 9 metal1 #adc1 #ahi 9 n]ve1 #aci1 #ahi 9 plant1 #cj1 #cb1 #gh1 #gi1 #ahi additive effect ( /imulus on1 9 metal1 #ace 9 plant1 #cg an/hetics1 effect (1 on1 9 n]ve1 #gb 9 plant1 #cj1 #gc1 #gd1 #ge anneal+1 effect (1 on1 9 metal1 #aja1 #ach by me?od ( block1 #bh1 #hb1 #ib by negative v>iation1 #i1 #ah1 #hg1 #ahc by relative depression1 #hg by relative exaltation1 #hi conditions = obta9+1 #f1 #hf1 #hg cont9u\s trans=mation f positive to negative 9 metal1 #aae decl9e & rev]sal (1 "u cont9u\s light 9 photo-s5sitive cell1 #aff decl9e & rev]sal (1 "u cont9u\s light 9 ret9a1 #aff depressants1 effect (1 on inorganic1 #adb dim9ution (4 ,see ,fatigue diphasic 9 metal1 #aac1 #aad1 #aae1 #aaf1 #ahh 9 n]ve1 #ahh 9 plant1 #df1 #ahh dose1 effect (1 on inorganic1 #hi1 #adf1 #ahi on1 9 plant1 #gi1 #ahi enhancem5t (1 aft] cont9u\s /imulation 9 metal1 #abg1 #abh1 #ahf enhancem5t (1 aft] cont9u\s /imulation 9 n]ve1 #abg1 #ahf maximum effect due to sup]position ( /imulus1 #ce1 #acf measure ( physiological activity1 #ac molecul> friction1 effect (1 on1 #ajh1 #aji modification1 effect (1 on1 #aa1 #dh1 #abc1 #abe1 #abi1 #afd1 #ahg physiological "* (1 9 plant1 #cj positive & negative1 #aa prolongation ( recov]y 91 by 'poison' 9 metal1 #ade prolongation ( recov]y 91 by 'poison' 9 muscle1 #add prolongation ( recov]y 91 f ov]/ra91 #ajf relation betwe51 & /imulus 9 metal1 #acd1 #ace 9 muscle1 #eb 9 n]ve1 #eb 9 plant1 #eb1 #ec1 #ed 9 real & artificial ret91 #afb /aircase effect1 9 metal1 #abb1 #ahf 9 plant1 #cg1 #ahf /imulant1 effect (1 on1 9 metal1 #ada temp]ature1 effect (1 on4 ,see ,temp]ature ?re%old (1 #ace to light4 ,see ,light uni=m 9 metal1 #ajb1 #ahd 9 n]ve1 #ahd 9 plant1 #cf1 #ahd univ]sal applicability (1 #ab me*anical1 #a ret9al4 ,see ,light simultane\s me*anical & electrical record (1 #ac ,ret9a4 ,see ,light ,s&]son1 ,burdon-1 on electrical response 9 s5sitive plants1 #ad ,spr+-tapp]1 me*anical /imulus by1 #bc ,/aircase effect 9 metal1 #abb1 #ahf 9 muscle1 #abb1 #ahf 9 plant1 #cg1 #ahf ,/e9] on ret9al response1 #adi ,/imuli1 maximum effect due to sup]position (1 9 metal1 #acf 9 muscle1 #cf 9 plant1 #cf ,/imulus1 advantages ( vibrational1 #be & response1 relation betwe51 9 metal1 #acd1 #ace 9 muscle1 #eb 9 n]ve1 #eb 9 plant1 #eb1 #ec1 #ed 9 real & artificial ret91 #afb effect ( diff]5t k9ds (1 #b me*anical1 by spr+-tapp]1 #bd conditions = ma9ta9+ uni=mity (1 #bf means ( graduat+ int5sity (1 #bb1 #if vibrational1 #bd1 #be1 #bf ,temp]ature1 dea?-po9ts 9 plants1 #fa1 #fc effect (1 on response 9 metal1 #aaa 9 photo-s5sitive cell1 #aeh 9 plants1 #cb1 #fj-fi 9 ret9a1 #aeh increas$ s5sitiv5ess 9 plant due to v>iation (1 #ff1 #fg ,vibrational /imulus1 #bd1 #be1 #bf ,vision1 b9ocul> alt]nation (1 #age effect ( v>i\s conditions on ! p]iod ( b9ocul> alt]nation (1 #agg ,visual images1 revival (1 #agg impression1 unconsci\s1 #agh impulse1 *emical !ory (1 #adh electrical !ory (1 #adi phantoms1 #agi recurr5ce1 #agd ,vital =ce1 #ac ,vitalism1 #ahb ,wall] on enhancem5t ( n]ve-response aft] cont9u\s /imulation1 #abg on relation betwe5 /imulus & response 9 muscle1 n]ve1 & ret9a1 #eb1 #afb on ret9al response1 #aej1 #aef1 #afe on rev]sal ( response 9 /ale n]ve & ret9a1 #aa1 #abd1 #afd on trans=mation f abnormal to normal response 9 n]ve aft] cont9u\s /imulation1 #abd ,,pr9t$ ,,by ,,spottiswoode ,,& ,,co4 ,,ltd41 ,,new-,,/reet ,,squ>e ,,london ---------------------------------------- -------------------------- ,transcrib]'s note3 ,! foll[+ pr9t] errors h be5 correct$3 ,diaphasic *ang$ to ,diphasic 7fig4 #bf caption7 ,da% add$ 7section on ,cont9u\s ,trans=mation7 ,blurr *ang$ to blur 7aft] fig4 #aaa7 ,9 creas$ *ang$ to increas$ 7aft] fig4 #aad7 ,! inconsi/5t hyph5ation ( break-d[n1 electro-motive & vibration-head is z 9 ! orig9al4 ---------------------------------------- --------------------------