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ver¡¡the¡¡style¡¡of¡¡architecture¡¡it¡¡helps¡¡to¡¡construct£»¡¡it¡¡never¡¡becomes¡¡a¡¡stone¡£¡¡And¡¡just¡¡as¡¡closely¡¡does¡¡each¡¡atom¡¡retain¡¡its¡¡own¡¡peculiar¡¡properties£»¡¡regardless¡¡of¡¡its¡¡surroundings¡£

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Though¡¡this¡¡early¡¡exposition¡¡of¡¡what¡¡has¡¡since¡¡been¡¡admitted¡¡to¡¡be¡¡a¡¡most¡¡important¡¡discovery¡¡was¡¡very¡¡fully¡¡outlined£»¡¡the¡¡generality¡¡of¡¡chemists¡¡gave¡¡it¡¡little¡¡heed¡¡till¡¡a¡¡decade¡¡or¡¡so¡¡later£»¡¡when¡¡three¡¡new¡¡elements£»¡¡gallium£»¡¡scandium£»¡¡and¡¡germanium£»¡¡were¡¡discovered£»¡¡which£»¡¡on¡¡being¡¡analyzed£»¡¡were¡¡quite¡¡unexpectedly¡¡found¡¡to¡¡fit¡¡into¡¡three¡¡gaps¡¡which¡¡Mendeleeff¡¡had¡¡left¡¡in¡¡his¡¡periodic¡¡scale¡£¡¡In¡¡effect¡¡the¡¡periodic¡¡law¡¡had¡¡enabled¡¡Mendeleeff¡¡to¡¡predicate¡¡the¡¡existence¡¡of¡¡the¡¡new¡¡elements¡¡years¡¡before¡¡they¡¡were¡¡discovered¡£¡¡Surely¡¡a¡¡system¡¡that¡¡leads¡¡to¡¡such¡¡results¡¡is¡¡no¡¡mere¡¡vagary¡£¡¡So¡¡very¡¡soon¡¡the¡¡periodic¡¡law¡¡took¡¡its¡¡place¡¡as¡¡one¡¡of¡¡the¡¡most¡¡important¡¡generalizations¡¡of¡¡chemical¡¡science¡£

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NEW¡¡WEAPONSSPECTROSCOPE¡¡AND¡¡CAMERA

But¡¡the¡¡atomic¡¡weights¡¡are¡¡not¡¡alone¡¡in¡¡suggesting¡¡the¡¡compound¡¡nature¡¡of¡¡the¡¡alleged¡¡elements¡£¡¡¡¡Evidence¡¡of¡¡a¡¡totally¡¡different¡¡kind¡¡has¡¡contributed¡¡to¡¡the¡¡same¡¡end£»¡¡from¡¡a¡¡source¡¡that¡¡could¡¡hardly¡¡have¡¡been¡¡imagined¡¡when¡¡the¡¡Proutian¡¡hypothesis£»¡¡was¡¡formulated£»¡¡through¡¡the¡¡tradition¡¡of¡¡a¡¡novel¡¡weapon¡¡to¡¡the¡¡armamentarium¡¡of¡¡the¡¡chemistthe¡¡spectroscope¡£¡¡¡¡The¡¡perfection¡¡of¡¡this¡¡instrument£»¡¡in¡¡the¡¡hands¡¡of¡¡two¡¡German¡¡scientists£»¡¡Gustav¡¡Robert¡¡Kirchhoff¡¡and¡¡Robert¡¡Wilhelm¡¡Bunsen£»¡¡came¡¡about¡¡through¡¡the¡¡investigation£»¡¡towards¡¡the¡¡middle¡¡of¡¡the¡¡century£»¡¡of¡¡the¡¡meaning¡¡of¡¡the¡¡dark¡¡lines¡¡which¡¡had¡¡been¡¡observed¡¡in¡¡the¡¡solar¡¡spectrum¡¡by¡¡Fraunhofer¡¡as¡¡early¡¡as¡¡1815£»¡¡and¡¡by¡¡Wollaston¡¡a¡¡decade¡¡earlier¡£¡¡It¡¡was¡¡suspected¡¡by¡¡Stokes¡¡and¡¡by¡¡Fox¡¡Talbot¡¡in¡¡England£»¡¡but¡¡first¡¡brought¡¡to¡¡demonstration¡¡by¡¡Kirchhoff¡¡and¡¡Bunsen£»¡¡that¡¡these¡¡lines£»¡¡which¡¡were¡¡known¡¡to¡¡occupy¡¡definite¡¡positions¡¡in¡¡the¡¡spectrum£»¡¡are¡¡really¡¡indicative¡¡of¡¡particular¡¡elementary¡¡substances¡£¡¡By¡¡means¡¡of¡¡the¡¡spectroscope£»¡¡which¡¡is¡¡essentially¡¡a¡¡magnifying¡¡lens¡¡attached¡¡to¡¡a¡¡prism¡¡of¡¡glass£»¡¡it¡¡is¡¡possible¡¡to¡¡locate¡¡the¡¡lines¡¡with¡¡great¡¡accuracy£»¡¡and¡¡it¡¡was¡¡soon¡¡shown¡¡that¡¡here¡¡was¡¡a¡¡new¡¡means¡¡of¡¡chemical¡¡analysis¡¡of¡¡the¡¡most¡¡exquisite¡¡delicacy¡£¡¡It¡¡was¡¡found£»¡¡for¡¡example£»¡¡that¡¡the¡¡spectroscope¡¡could¡¡detect¡¡the¡¡presence¡¡of¡¡a¡¡quantity¡¡of¡¡sodium¡¡so¡¡infinitesimal¡¡as¡¡the¡¡one¡¡two¡­hundred¡­thousandth¡¡of¡¡a¡¡grain¡£¡¡¡¡But¡¡what¡¡was¡¡even¡¡more¡¡important£»¡¡the¡¡spectroscope¡¡put¡¡no¡¡limit¡¡upon¡¡the¡¡distance¡¡of¡¡location¡¡of¡¡the¡¡substance¡¡it¡¡tested£»¡¡provided¡¡only¡¡that¡¡sufficient¡¡light¡¡came¡¡from¡¡it¡£¡¡The¡¡experiments¡¡it¡¡recorded¡¡might¡¡be¡¡performed¡¡in¡¡the¡¡sun£»¡¡or¡¡in¡¡the¡¡most¡¡distant¡¡stars¡¡or¡¡nebulae£»¡¡indeed£»¡¡one¡¡of¡¡the¡¡earliest¡¡feats¡¡of¡¡the¡¡instrument¡¡was¡¡to¡¡wrench¡¡from¡¡the¡¡sun¡¡the¡¡secret¡¡of¡¡his¡¡chemical¡¡constitution¡£

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