But　beyond　that　I　could　not　go；　and；　perforce；　was　compelled　to　lie
  awake　and　think　and　think。　　And　that　way；　for　an　active…brained　man；
  lay　madness。
  I　sought　devices　to　enable　me　mechanically　to　abide　my　waking　hours。
  I　squared　and　cubed　long　series　of　numbers；　and　by　concentration　and
  will　carried　on　most　astonishing　geometric　progressions。　　I　even
  dallied　with　the　squaring　of　the　circle　。　。　。　until　I　found　myself
  beginning　to　believe　that　that　possibility　could　be　accomplished。
  Whereupon；　realizing　that　there；　too；　lay　madness；　I　forwent　the
  squaring　of　the　circle；　although　I　assure　you　it　required　a
  considerable　sacrifice　on　my　part；　for　the　mental　exercise　involved
  was　a　splendid　time…killer。
  By　sheer　visualization　under　my　eyelids　I　constructed　chess…boards
  and　played　both　sides　of　long　games　through　to　checkmate。　　But　when
  I　had　become　expert　at　this　visualized　game　of　memory　the　exercise
  palled　on　me。　　Exercise　it　was；　for　there　could　be　no　real　contest
  when　the　same　player　played　both　sides。　　I　tried；　and　tried　vainly；
  to　split　my　personality　into　two　personalities　and　to　pit　one
  against　the　other。　　But　ever　I　remained　the　one　player；　with　no
  planned　ruse　or　strategy　on　one　side　that　the　other　side　did　not
  immediately　apprehend。
  And　time　was　very　heavy　and　very　long。　　I　played　games　with　flies；
  with　ordinary　houseflies　that　oozed　into　solitary　as　did　the　dim
  gray　light；　and　learned　that　they　possessed　a　sense　of　play。　　For
  instance；　lying　on　the　cell　floor；　I　established　an　arbitrary　and
  imaginary　line　along　the　wall　some　three　feet　above　the　floor。　　When
  they　rested　on　the　wall　above　this　line　they　were　left　in　peace。
  The　instant　they　lighted　on　the　wall　below　the　line　I　tried　to　catch
  them。　　I　was　careful　never　to　hurt　them；　and；　in　time；　they　knew　as
  precisely　as　did　I　where　ran　the　imaginary　line。　　When　they　desired
  to　play；　they　lighted　below　the　line；　and　often　for　an　hour　at　a
  time　a　single　fly　would　engage　in　the　sport。　　When　it　grew　tired；　it
  would　come　to　rest　on　the　safe　territory　above。
  Of　the　dozen　or　more　flies　that　lived　with　me；　there　was　only　one
  who　did　not　care　for　the　game。　　He　refused　steadfastly　to　play；　and；
  having　learned　the　penalty　of　alighting　below　the　line；　very
  carefully　avoided　the　unsafe　territory。　　That　fly　was　a　sullen；
  disgruntled　creature。　　As　the　convicts　would　say；　it　had　a　〃grouch〃
  against　the　world。　　He　never　played　with　the　other　flies　either。　　He
  was　strong　and　healthy；　too；　for　I　studied　him　long　to　find　out。
  His　indisposition　for　play　was　temperamental；　not　physical。
  Believe　me；　I　knew　all　my　flies。　　It　was　surprising　to　me　the
  multitude　of　differences　I　distinguished　between　them。　　Oh；　each　was
  distinctly　an　individualnot　merely　in　size　and　markings；　strength；
  and　speed　of　flight；　and　in　the　manner　and　fancy　of　flight　and　play；
  of　dodge　and　dart；　of　wheel　and　swiftly　repeat　or　wheel　and　reverse；
  of　touch　and　go　on　the　danger　wall；　or　of　feint　the　touch　and　alight
  elsewhere　within　the　zone。　　They　were　likewise　sharply
  differentiated　in　the　minutest　shades　of　mentality　and　temperament。
  I　knew　the　nervous　ones；　the　phlegmatic　ones。　　There　was　a　little
  undersized　one　that　would　fly　into　real　rages；　sometimes　with　me；
  sometimes　with　its　fellows。　　Have　you　ever　seen　a　colt　or　a　calf
  throw　up　its　heels　and　dash　madly　about　the　pasture　from　sheer
  excess　of　vitality　and　spirits？　　Well；　there　was　one　flythe
  keenest　player　of　them　all；　by　the　waywho；　when　it　had　alighted
  three　or　four　times　in　rapid　succession　on　my　taboo　wall　and
  succeeded　each　time　in　eluding　the　velvet…careful　swoop　of　my　hand；
  would　grow　so　excited　and　jubilant　that　it　would　dart　around　and
  around　my　head　at　top　speed；　wheeling；　veering；　reversing；　and
  always　keeping　within　the　limits　of　the　narrow　circle　in　which　it
  celebrated　its　triumph　over　me。
  Why；　I　could　tell　well　in　advance　when　any　particular　fly　was　making
  up　its　mind　to　begin　to　play。　　There　are　a　thousand　details　in　this
  one　matter　alone　that　I　shall　not　bore　you　with；　although　these
  details　did　serve　to　keep　me　from　being　bored　too　utterly　during
  that　first　period　in　solitary。　　But　one　thing　I　must　tell　you。　　To
  me　it　is　most　memorablethe　time　when　the　one　with　a　grouch；　who
  never　played；　alighted　in　a　moment　of　absent…mindedness　within　the
  taboo　precinct　and　was　immediately　captured　in　my　hand。　　Do　you
  know；　he　sulked　for　an　hour　afterward。
  And　the　hours　were　very　long　in　solitary；　nor　could　I　sleep　them　all
  away；　nor　could　I　while　them　away　with　house…flies；　no　matter　how
  intelligent。　　For　house…flies　are　house…flies；　and　I　was　a　man；　with
  a　man's　brain；　and　my　brain　was　trained　and　active；　stuffed　with
  culture　and　science；　and　always　geared　to　a　high　tension　of
  eagerness　to　do。　　And　there　was　nothing　to　do；　and　my　thoughts　ran
  abominably　on　in　vain　speculations。　　There　was　my　pentose　and
  methyl…pentose　determination　in　grapes　and　wines　to　which　I　had
  devoted　my　last　summer　vacation　at　the　Asti　Vineyards。　　I　had　all
  but　completed　the　series　of　experiments。　　Was　anybody　else　going　on
  with　it；　I　wondered；　and　if　so；　with　what　success？
  You　see；　the　world　was　dead　to　me。　　No　news　of　it　filtered　in。　　The
  history　of　science　was　making　fast；　and　I　was　interested　in　a
  thousand　subjects。　　Why；　there　was　my　theory　of　the　hydrolysis　of
  casein　by　trypsin；　which　Professor　Walters　had　been　carrying　out　in
  his　laboratory。　　Also；　Professor　Schleimer　had　similarly　been
  collaborating　with　me　in　the　detection　of　phytosterol　in　mixtures　of
  animal　and　vegetable　fats。　　The　work　surely　was　going　on；　but　with
  what　results？　　The　very　thought　of　all　this　activity　just　beyond　the
  prison　walls　and　in　which　I　could　take　no　part；　of　which　I　was　never
  even　to　hear；　was　maddening。　　And　in　the　meantime　I　lay　there　on　my
  cell　floor　and　played　games　with　house…flies。
  And　yet　all　was　not　silence　in　solitary。　　Early　in　my　confinement　I
  used　to　hear；　at　irregular　intervals；　faint；　low　tappings。　　From
  farther　away　I　also　heard　fainter　and　lower　tappings。　　Continually
  these　tappings　were　interrupted　by　the　snarling　of　the　guard。　　On
  occasion；　when　the　tapping　went　on　too　persistently；　extra　guards
  were　summoned；　and　I　knew　by　the　sounds　that　men　were　being　strait…
  jacketed。
  The　matter　was　easy　of　explanation。　　I　had　known；　as　every　prisoner
  in　San　Quentin　knew；　that　the　two　men　in　solitary　were　Ed　Morrell
  and　Jake　Oppenheimer。　　And　I　knew　that　these　were　the　two　men　who
  tapped　knuckle…talk　to　each　other　and　were　punished　for　so　doing。
  That　the　code　they　used　was　simple　I　had　not　the　slightest　doubt；
  yet　I　devoted　many　hours　to　a　vain　effort　to　work　it　out。　　Heaven
  knowsit　had　to　be　simple；　yet　I　could　not　make　head　nor　tail　of
  it。　　And　simple　it　proved　to　be；　when　I　learned　it；　and　simplest　of
  all　proved　the　trick　they　employed　which　had　so　baffled　me。　　Not
  only　each　day　did　they　change　the　point　in　the　alphabet　where　the
  code　initialled；　but　they　changed　it　every　conversation；　and；　often；
  in　the　midst　of　a　conversation。
  Thus；　there　came　a　day　when　I　caught　the　code　at　the　right　initial；
  listened　to　two　clear　sentences　of　conversation；　and；　the　next　time
  they　talked；　failed　to　understand　a　word。　　But　that　first　time！
  〃SayEdwhatwould　yougiverightnowforbrownpapers
  andasackofBullDurham！〃　asked　the　one　who　tapped　from
  farther　away。
  I　nearly　cried　out　in　my　joy。　　Here　was　communication！　　Here　was
  companionship！　　I　listened　eagerly；　and　the　nearer　tapping；　which　I
  guessed　must　be　Ed　Morrell's；　replied：
  〃Iwoulddotwentyhoursstraitinthejacketforafive…
  …centsack〃
  Then　came　the　snarling　interruption　of　the　guard：　　〃Cut　that　out；
  Morrell！〃
  It　may　be　thought　by　the　layman　that　the　worst　has　been　done　to　men
  sentenced　to　solitary　for　life；　and　therefore　that　a　mere　guard　has
  no　way　of　compelling　obedience　to　his　order　to　cease　tapping。
  But　the　jacket　remains。　　Starvation　remains。　　Thirst　remains。　　Man…
  handling　remains。　　Truly；　a　man　pent　in　a　narrow　cell　is　very
  helpless。
  So　the　tapping　ceased；　and　that　night；　when　it　was　next　resumed；　I
  was　all　at　sea　again。　　By　pre…arrangement　they　had　changed　the
  initial　letter　of　the　code。　　But　I　had　caught　the　clue；　and；　in　the
  matter　of　several　days；　occurred　again　the　same　initialment　I　had
  understood。　　I　did　not　wait　on　courtesy。
  〃Hello；〃　I　tapped
  〃Hello；　stranger；〃　Morrell　tapped　back；　and；　from　Oppenheimer；
  〃Welcome　to　our　city。〃
  They　were　curious　to　know　who　I　was；　how　long　I　was　condemned　to
  solitary；　and　why　I　had　been　so　condemned。　　But　all　this　I　put　to
  the　side　in　order　first　to　learn　their　system　of　changing　the　code
  initial。　　After　I　had　this　clear；　we　talked。　　It　was　a　great　day；
  for　the　two　lifers　had　become　three；　although　they　accepted　me　only
  on　probation。　　As　they　told　me　long　after；　they　feared　I　might　be　a
  stool　placed　there　to　work　a　fra