Am.  Jour.  Pharm.  \ 
March,  1888.  ) 
The  Home  of  the  Cinchonas. 
143 
regions  which  are  temporarily  wanting  in  humidity,  are  fed  from  those  which 
are  better  suppUed.  But  that  is  not  all;  there  is  an  additional  and  peculiar 
feature.  The  equalizing  process  is  not  only  regional,  but  temporal  as  well,  for 
at  certain  hours  of  the  d^y  there  is  in  most  sections  a  discharge  of  rain  which 
is  said  to  be  almost  as  regular  as  the  striking  of  a  clock.  For  the  most  part 
these  showers  are  comparatively  gentle,  as  we  should  expect  from  the  compara- 
tive uniformity  of  the  conditions,  but  when  these  clouds  have  reached  the 
mountains  an  entire  change  occurs  in  all  their  conditions.  Up  to  this  point 
they  have,  upon  the  whole,  gained  more  than  they  have  lost,  and  they  reach 
the  Andean  foot  hills  like  an  M.  D.  who  comes  home  from  a  meeting  with  his 
colleagues  at  five  o'clock  in  the  morning  after  hospitabh^  entertaining  some 
favorite  guest,  very  top  heavy  with  wetness. 
What  now  are  the  conditions  on  which  cloud  precipitation  depends  ?  Only 
one,  although  it  may  be  produced  in  a  variety  of  ways  ;  an  increase  of  density. 
On  striking  the  first  range  of  hills,  this  increase  of  density  is  produced  by  com- 
pression of  the  clouds  between  the  hills  and  other  clouds  that  are  pressing  ou 
behind  them.  They  at  once  discharge  great  volumes  of  water  upon  the  plains 
below.  The  cloud  thus  lightened  endeavors  to  escape  upward  over  the  tops 
of  the  hills,  but  reaching  the  colder  upper  strata,  there  is  another  increase  in 
density  and  fresh  precipitation  occurs.  This  operation  is  again  and  again  re- 
peated as  the  :^50  miles  of  s  eadily  increasing  elevation  are  passed,  until  finally, 
the  tattered  remnants  of  the  recent  cloud  dome  find  themselves  among  the  jag- 
ged peaks  of  the  highest  ranges.  From  one  or  another  of  these  peaks  there  is 
an  almost  constant  discharge  of  electricity,  and  this  completes  the  annihilation 
of  the  cloud-forces,  the  winds  which  cross  to  the  other  side  carrying  with  them 
but  the  merest  traces  of  moisture.  Now  there  is  a  point  upon  this  mountain 
slope  where  this  strife  among  the  elements  seems  more  violent  than  elsewhere. 
A  narrow  belt  of  between  three  thousand  and  five  thousand  feet  above  the  level 
of  the  sea  where  it  seems  that  peak  and  forest  have  united  in  a  resolution 
that  no  cloud  shall  pass  without  being  broken  to  its  centie.  In  the  midst  of 
this  scene  of  vapory  turmoil  the  cinchona  has  its  home.  Far  to  the  northward, 
in  the  equatorial  region,  they  creep  up  to  a  higher  elevation,  and  in  the  Co- 
chabamba  region  of  Southern  Bolivia  the  cinchona  belt  is  limited  upward  to 
between  five  thousand  and  five  thousand  five  hundred  feet,  and  downward  to 
two  thousand  five  hundred  or  three  thousand  feet.  The  precise  conditions  of 
heat  and  moisture  are  hard  to  find,  hence  the  small  number  of  places  where  the 
cultivation  of  cinchona  has  been  even  partially  successful.  And  hence  the  fact 
that  the  United  States  has  no  territory  where  the  faintest  hope  of  its  produc- 
tion can  ever  be  entertained.  The  water  supplv  must  be  abundant  and  con- 
stant. Irrigation,  however  abundant,  is  entirely  inadequate  in  the  cultivation 
of  these  trees.  The  aerial  as  well  as  the  subterranean  portion  must  be  bathed 
in  moisture.  It  is  true  that  there  is  a  period  of  several  weeks  when  the  rains 
almost  entirely  cease.  But  this  occurs  just  at  the  close  of  the  rainy  season 
when  the  earth  is  saturated  with  water,  so  that  up  to  the  re-commencement  of 
the  rains  there  is  no  period  when  the  atmosphere,  by  evaporation  from  the 
surface  of  the  earth  and  the  exuberant  mass  of  foliage,  is  not  sufiiciently  hu- 
mid. It  is  to  be  remembered  that  the  supply  of  water  does  not  cease  with  the 
cessation  of  the  rains.  Ten  thousand  feet  of  mountain  slope  lie  back  of  the 
cinchona  belt,  and  conserve  the  rain-fall  in  the  crevices  of  the  rocks  and  in 
