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Show - - - - - - Keein Win WinerK U UI Uk Ud Uci I k UI I d ci erK ern ev e _ v ! ) gceonco.ervtce-\V\9J gceonco.ervtceV9J gceonco.ervtce gceoncoervtce V 9J cicnco cll'nco cllnco . ' " ' . servic fvce ! * - \ W\TJ W TJ W\'U 'U U ' \ ' \ ' Son Sentce Sor\lce Sor lce \ Ice . . . Chemicalof Chemical Chenrical of f Sight Sightb SightRebuild SightMade b l\fade l fade Blade \ toItself to Rebuild RebuildItself Itself Itself1n in 1n TubeVisual Tube TubeVisual Visual PUI Puiple Pulnle pIc Now NowIs NowIs Is Rcgencl Rebnenel Regeneiated RegeneiatedTT'lSUAL ated atedISUAL VISUAL TT'lSUAL TTlSUAL ' ISUAL purple , a chemIcal chemIcalcompound chemicalcompound chemicalV compound in 111 the e ) } e , and andnecessary andnecessary andnecessary necessary for seeing seell1g , has been beenmade beenmade beenmade made to rebuild rebmlcl 1tself1I1 itselfin itself 1tself in 1I1 a test testtube testtube testtube tube under controllede.pCII controllede controlled e\.pCII- e.pCII e .pCII pCII e.pCIImental e cvpcn-mental cvpcn mental ' \ . peii- peii peiimental - - mental conditions , in 111 ul the lab- lab laboratory laboratory lab laboratory - oratory of Prof Selig ' Hecht I-Jecht I Jecht Hechtof Hcchtof IJechtof - of Columbia ttlll\ ttlll mu \ ' . . This is the first time that the pro process process process cess has taken tahen place under fu11y fu11ycontrolled full ; controlled conditions , which wluch mahe make makeits maheits makeits its repetition repebbon possible It is 15 the first firsttIme firsttime firsttime tIme since smce 1878 that visu-il visu il vIsul visuil ' ) - purple purplehas purplehas purplehas has been re regenerated enerated at all , , al although although although though many phJ physiologists SIologISts ha\ ha hae hatrIed ha ha\etried ha etried 'e e 'etried \ ' e trIed wihout success to repeat theexperiment the thecperlment theexperiment cperlment experiment " { of Dr W Kuhne Kulme of ofHeIdelberg ofHeidelberg ofHeidelberg HeIdelberg university ul1l\ersIty ul1l ersIty uni'crsity unicrsity \ ' , who in m thatyear that thatear year ear reported having havmg accomplIshed accomplIshedthIS accomplishedthis thIS very verJ " e\citmg e citmg e\.cltmg e.cltmg .cltmg cltmg exciting \ . biochemical featProfessor featProfessor feat featProfessor Professor Hccht's Hcchts Hecht's Hechts ' ' associates 111 in 111Ins inhis inhis Ins his present research are Dis DI S AunnM Aur111 Aurin Aur111M AurinM M Chase , Simon Shiaer Shlaer and Charles CharlesHalg CharlesHaig CharlesHaig CharlesHaiground Halg Haig Halground Haiground round in III the Retina Retma . Visual purple is a pinkish pmkIsh purple purplepIgment purplepigment purplepigment pIgment or dj dsestuff d estufE estuff of 111volvedchemIcal involvedchemical 111volved involved involvedchemical chemIcal composition found in 111 the therod therod therod rod cells of the tl.e tle . rctmi retm't retmt retina ' , or light sen senI senSIb sensiti'e sensiti\e sensiti e I SIb\ SIb SIbe siti'e sitie \ ' e layer of the eye Both in 111 the thelIvmg theliving theliving lIvmg living eye . , and'ihen andihen and " ' when "hen hen chemically e ex extracted extractcd " { tracted 111 into to a glass vessel , , It Itloses itloses itloses loses its 11s color when "hen hen Then " Illummated illuminated illuminatedfirst , , first turning turnmg j y yellow ellow chow and then com corn completeI cornpletelb cornpleteb pleteI pletelb ) colorlessIn colorlessIii colorless In Iii the glass vessel , it has never neverbeen neverbeen neverbeen been turned back to its original orlg111al col color color color or again agam , except in m the 1878 ex- ex experunent experiment ex experiment - - periment perunent of Dr Kuhne But in m the the1.1vmg theliving theliving 1.1vmg 11vmg living . ej eye e e the reaction is reversible reversible.that reversiblethat , . that is , it If the light is shut off the thevIsual thevisual thevisual vIsual purple forms itself anew from fromthe fromthe fromthe the colorless product of its pboto-chemical pboto chemical photo- photo photochemIcal photochemical - - - chemIcal breahdomPhj breakdownPhysiologists breakdown breahdom breakdownPhysiologists , Phj Physiologists sIOloglsts regard the success successof successof successof of Professor Hecht and his as assoclates associates associates soclates sociates in m reversing reversmg the bleachmg bleaching bleachingof bleachmgof of visual purple at111 at will \\111 111 \ \ as a very verysubstantIal verysubstantial verysubstantial substantIal forward forv.ard forvard . step toward the theultImate theultimate theultimate ultImate understanding understandmg of the pro process process process cess of seeing seemg because it is now nowpossIble nowpossible nowpossible possIble to perform controlled experiments ex- ex expenments ex experiments - - periments penments in m one verj verb ver > vital part of ofthat ofthat ofthat that process , where e\.perrments e.perrments e .perrments perrments experiments e.perrmentshave experimentshave experimentshave \ . have been impossible until nowVIsual nowVisual now nowVisual Visual purple for the present re research research research search was obtained obtamed from the eyes eyesof eyesof eyesof of frogs The Tbe animals anunals were kept m in mthe inthe inthe the dark darh for several hours , then thenthey thenthey thenthey they were killed quickly qUlchl ) , and the thepIgment thepigment thepigment pIgment removed from their eyes eyesby eyesby eyesby by chemical extraction e\.tractIon e.tractIon e .tractIon tractIon \ . processes |