From　very　fact；　because　they　noxious　be
  Unto　all　birds。　For　when　above　those　spots
  In　horizontal　flight　the　birds　have　come；
  Forgetting　to　oar　with　wings；　they　furl　their　sails；
  And；　with　down…drooping　of　their　delicate　necks；
  Fall　headlong　into　earth；　if　haply　such
  The　nature　of　the　spots；　or　into　water；
  If　haply　spreads　thereunder　Birdless　tarn。
  Such　spot's　at　Cumae；　where　the　mountains　smoke；
  Charged　with　the　pungent　sulphur；　and　increased
  With　steaming　springs。　And　such　a　spot　there　is
  Within　the　walls　of　Athens；　even　there
  On　summit　of　Acropolis；　beside
  Fane　of　Tritonian　Pallas　bountiful；
  Where　never　cawing　crows　can　wing　their　course；
  Not　even　when　smoke　the　altars　with　good　gifts；…
  But　evermore　they　flee…　yet　not　from　wrath
  Of　Pallas；　grieved　at　that　espial　old；
  As　poets　of　the　Greeks　have　sung　the　tale；
  But　very　nature　of　the　place　compels。
  In　Syria　also…　as　men　say…　a　spot
  Is　to　be　seen；　where　also　four…foot　kinds；
  As　soon　as　ever　they've　set　their　steps　within；
  Collapse；　o'ercome　by　its　essential　power；
  As　if　there　slaughtered　to　the　under…gods。
  Lo；　all　these　wonders　work　by　natural　law；
  And　from　what　causes　they　are　brought　to　pass
  The　origin　is　manifest；　so；　haply；
  Let　none　believe　that　in　these　regions　stands
  The　gate　of　Orcus；　nor　us　then　suppose；
  Haply；　that　thence　the　under…gods　draw　down
  Souls　to　dark　shores　of　Acheron…　as　stags；
  The　wing…footed；　are　thought　to　draw　to　light；
  By　sniffing　nostrils；　from　their　dusky　lairs
  The　wriggling　generations　of　wild　snakes。
  How　far　removed　from　true　reason　is　this；
  Perceive　thou　straight；　for　now　I'll　try　to　say
  Somewhat　about　the　very　fact。
  And；　first；
  This　do　I　say；　as　oft　I've　said　before：
  In　earth　are　atoms　of　things　of　every　sort；
  And　know；　these　all　thus　rise　from　out　the　earth…
  Many　life…giving　which　be　good　for　food；
  And　many　which　can　generate　disease
  And　hasten　death；　O　many　primal　seeds
  Of　many　things　in　many　modes…　since　earth
  Contains　them　mingled　and　gives　forth　discrete。
  And　we　have　shown　before　that　certain　things
  Be　unto　certain　creatures　suited　more
  For　ends　of　life；　by　virtue　of　a　nature；
  A　texture；　and　primordial　shapes；　unlike
  For　kinds　alike。　Then　too　'tis　thine　to　see
  How　many　things　oppressive　be　and　foul
  To　man；　and　to　sensation　most　malign：
  Many　meander　miserably　through　ears；
  Many　in…wind　athrough　the　nostrils　too；
  Malign　and　harsh　when　mortal　draws　a　breath；
  Of　not　a　few　must　one　avoid　the　touch；
  Of　not　a　few　must　one　escape　the　sight；
  And　some　there　be　all　loathsome　to　the　taste；
  And　many；　besides；　relax　the　languid　limbs
  Along　the　frame；　and　undermine　the　soul
  In　its　abodes　within。　To　certain　trees
  There　hath　been　given　so　dolorous　a　shade
  That　often　they　gender　achings　of　the　head；
  If　one　but　be　beneath；　outstretched　on　the　sward。
  There　is；　again；　on　Helicon's　high　hills
  A　tree　that's　wont　to　kill　a　man　outright
  By　fetid　odour　of　its　very　flower。
  And　when　the　pungent　stench　of　the　night…lamp；
  Extinguished　but　a　moment　since；　assails
  The　nostrils；　then　and　there　it　puts　to　sleep
  A　man　afflicted　with　the　falling　sickness
  And　foamings　at　the　mouth。　A　woman；　too；
  At　the　heavy　castor　drowses　back　in　chair；
  And　from　her　delicate　fingers　slips　away
  Her　gaudy　handiwork；　if　haply　she
  Hath　got　the　whiff　at　menstruation…time。
  Once　more；　if　thou　delayest　in　hot　baths；
  When　thou　art　over…full；　how　readily
  From　stool　in　middle　of　the　steaming　water
  Thou　tumblest　in　a　fit！　How　readily
  The　heavy　fumes　of　charcoal　wind　their　way
  Into　the　brain；　unless　beforehand　we
  Of　water　've　drunk。　But　when　a　burning　fever；
  O'ermastering　man；　hath　seized　upon　his　limbs；
  Then　odour　of　wine　is　like　a　hammer…blow。
  And　seest　thou　not　how　in　the　very　earth
  Sulphur　is　gendered　and　bitumen　thickens
  With　noisome　stench？…　What　direful　stenches；　too；
  Scaptensula　out…breathes　from　down　below；
  When　men　pursue　the　veins　of　silver　and　gold；
  With　pick…axe　probing　round　the　hidden　realms
  Deep　in　the　earth？…　Or　what　of　deadly　bane
  The　mines　of　gold　exhale？　O　what　a　look；
  And　what　a　ghastly　hue　they　give　to　men！
  And　seest　thou　not；　or　hearest；　how　they're　wont
  In　little　time　to　perish；　and　how　fail
  The　life…stores　in　those　folk　whom　mighty　power
  Of　grim　necessity　confineth　there
  In　such　a　task？　Thus；　this　telluric　earth
  Out…streams　with　all　these　dread　effluvia
  And　breathes　them　out　into　the　open　world
  And　into　the　visible　regions　under　heaven。
  Thus；　too；　those　Birdless　places　must　up…send
  An　essence　bearing　death　to　winged　things；
  Which　from　the　earth　rises　into　the　breezes
  To　poison　part　of　skiey　space；　and　when
  Thither　the　winged　is　on　pennons　borne；
  There；　seized　by　the　unseen　poison；　'tis　ensnared；
  And　from　the　horizontal　of　its　flight
  Drops　to　the　spot　whence　sprang　the　effluvium。
  And　when　'thas　there　collapsed；　then　the　same　power
  Of　that　effluvium　takes　from　all　its　limbs
  The　relics　of　its　life。　That　power　first　strikes
  The　creatures　with　a　wildering　dizziness；
  And　then　thereafter；　when　they're　once　down…fallen
  Into　the　poison's　very　fountains；　then
  Life；　too；　they　vomit　out　perforce；　because
  So　thick　the　stores　of　bane　around　them　fume。
  Again；　at　times　it　happens　that　this　power；
  This　exhalation　of　the　Birdless　places；
  Dispels　the　air　betwixt　the　ground　and　birds；
  Leaving　well…nigh　a　void。　And　thither　when
  In　horizontal　flight　the　birds　have　come；
  Forthwith　their　buoyancy　of　pennons　limps；
  All　useless；　and　each　effort　of　both　wings
  Falls　out　in　vain。　Here；　when　without　all　power
  To　buoy　themselves　and　on　their　wings　to　lean；
  Lo；　nature　constrains　them　by　their　weight　to　slip
  Down　to　the　earth；　and　lying　prostrate　there
  Along　the　well…nigh　empty　void；　they　spend
  Their　souls　through　all　the　openings　of　their　frame。
  。　　　　　。　　　　　。　　　　　。　　　　　。　　　　　。
  Further；　the　water　of　wells　is　colder　then
  At　summer　time；　because　the　earth　by　heat
  Is　rarefied；　and　sends　abroad　in　air
  Whatever　seeds　it　peradventure　have
  Of　its　own　fiery　exhalations。
  The　more；　then；　the　telluric　ground　is　drained
  Of　heat；　the　colder　grows　the　water　hid
  Within　the　earth。　Further；　when　all　the　earth
  Is　by　the　cold　compressed；　and　thus　contracts
  And；　so　to　say；　concretes；　it　happens；　lo；
  That　by　contracting　it　expresses　then
  Into　the　wells　what　heat　it　bears　itself。
  'Tis　said　at　Hammon's　fane　a　fountain　is；
  In　daylight　cold　and　hot　in　time　of　night。
  This　fountain　men　be…wonder　over…much；
  And　think　that　suddenly　it　seethes　in　heat
  By　intense　sun；　the　subterranean；　when
  Night　with　her　terrible　murk　hath　cloaked　the　lands…
  What's　not　true　reasoning　by　a　long　remove：
  I'　faith　when　sun　o'erhead；　touching　with　beams
  An　open　body　of　water；　had　no　power
  To　render　it　hot　upon　its　upper　side；
  Though　his　high　light　possess　such　burning　glare；
  How；　then；　can　he；　when　under　the　gross　earth；
  Make　water　boil　and　glut　with　fiery　heat？…
  And；　specially；　since　scarcely　potent　he
  Through　hedging　walls　of　houses　to　inject
  His　exhalations　hot；　with　ardent　rays。
  What；　then's；　the　principle？　Why；　this；　indeed：
  The　earth　about　that　spring　is　porous　more
  Than　elsewhere　the　telluric　ground；　and　be
  Many　the　seeds　of　fire　hard　by　the　water；
  On　this　account；　when　night　with　dew…fraught　shades
  Hath　whelmed　the　earth；　anon　the　earth　deep　down
  Grows　chill；　contracts；　and　thuswise　squeezes　out
  Into　the　spring　what　seeds　she　holds　of　fire
  （As　one　might　squeeze　with　fist）；　which　render　hot
  The　touch　and　steam　of　the　fluid。　Next；　when　sun；
  Up…risen；　with　his　rays　has　split　the　soil
  And　rarefied　the　earth　with　waxing　heat；
  Again　into　their　ancient　abodes　return
  The　seeds　of　fire；　and　all　the　Hot　of　water
  Into　the　earth　retires；　and　this　is　why
  The　fountain　in　the　daylight　gets　so　cold。
  Besides；　the　water's　wet　is　beat　upon
  By　rays　of　sun；　and；　with　the　dawn；　becomes
  Rarer　in　texture　under　his　pulsing　blaze；
  And；　therefore；　whatso　seeds　it　holds　of　fire
  It　renders　up；　even　as　it　renders　oft
  The　frost　that　it　contains　within　itself
  And　thaws　its　ice　and　looseneth　the　knots。
  There　is；　moreover；　a　fountain　cold　in　kind
  That　makes　a　bit　of　tow　（above　it　held）
  Take　fire　forthwith　and　shoot　a　flame；　so；　too；
  A　pitch…pine　torch　will　kindle　and　flare　round
  Along　its　waves；　wherever　'tis　impelled
  Afloat　before　the　breeze。　No　marvel；　this：
  Because　full　many　seeds　of　heat　there　be
  Within　the　water；　and；　from　earth　itself
  Out　of　the　deeps　must　particles　of　fire
  Athrough　the　entire　fountain　surge　aloft；
  And　speed　in　exhalations　into　air
  Forth　and　abroad　（yet　not　in　numbers　enow
  As　to　make　hot　the　fountain）。　And；　moreo'er；
  Some　force　constrains　them；　scattered　through　the　water；
  Forthwith　to　burst　abroad；　and　to　combine
  In　flame　above。　Even　as　a　fountain　far
  There　is　at　Aradus　amid　the　sea；
  Which　bubbles　out　sweet　water　and　disparts
  From　round　itself　the　salt　waves；　and；　behold；
  In　many　another　region　the　broad　main
  Yields　to　the　thirsty　mariners　timely　help；
  Belching　sweet　waters　forth　amid　salt　waves。
  Just　so；　then；　can　those　seeds　of　fire　burst　forth
  Athrough　that　other　fount；　and　bubble　out
  Abroad　against　the　bit　of　tow；　and　when
  They　there　collect　or　cleave　unto　the　torch；
  Forthwith　they　readily　flash　aflame；　because
  The　tow　a