142 
The  Home  oj  the  Cinchonas. 
(  Am.  Jour.  Pliarm. 
\      March.  18SS. 
THE  HOME  OF  THE  CI^^CHOXAS. 
By  Dr.  H.  H.  Rusby.i 
Leaving  out  of  the  question  the  cold,  stormy  and  little  known  region  of  Cape 
Horn,  South  America  is  divided  by  the  Andes  into  two  portions,  having  almost 
nothing  in  common.  The  Cordilleras  which  extend  along  the  eastern  verge  of 
the  great  Andean  table  land,  while  only  a  few  miles  in  width,  mark  differ- 
ences in  soil,  climate,  productions  and  general  appearance  as  great  as  any  that 
are  to  be  observed  upon  the  globe,  and  present  an  obstacle  to  the  interchange 
of  organic  beings  far  more  effectual  than  the  broadest  ocean  could  constitute. . 
Upon  the  Pacific  coast  rain  is  in  many  regions  almost  unknown,  and  the  air  is 
so  destitute  of  humidity  that  it  is  said  that  the  inhabitants  never  die,  but  dry 
up  and  are  subsequently  blown  away  in  some  gale  of  wind.  Upon  the  other 
side  rain  is  so  constant  that  weeks  may  pass  when  the  sun  is  seen  for  scarcely 
an  entire  hour,  and  the  humidity  of  the  atmosphere  is  sometimes  so  great  that 
the  clouds  of  rising  vai)or  obscure  the  view  of  even  the  nearest  objects.  The 
west  Andean  region  is  marked  over  its  greater  extent  by  a  total  absence  of 
trees,  or  even  of  large  shrubs,  many  sections  being  destitute  of  even  a  vestige  of 
green.  The  east  Andean  region  on  the  contrary  presents  a  scene  of  impene- 
trable verdure,  reaching  from  near  the  summit  of  the  mountains  to  the  Atlantic 
Ocean,  three  thousand  miles  away.  With  the  former  region  we  have  nothing 
to  do.  Except  for  a  small  portion  of  Chili  it  produces  no  important  drug.  The 
portion  of  Chili  referred  to  yields  soap  bark,  chequen  and  boldo,  and  it  was 
here  that  I  discovered  the  properties  of  the  fabiana  imhricata,  or  pichi,  a  drug 
that  is  meeting  with  a  remarkably  uniform  success  in  the  treatment  of  cystitis. 
I  have  stated  that  the  eastern  Cordillera  forms  a  barrier  to  the  interchange  of 
species  between  the  two  regions.  The  barrier  is  not  a  direct  one.  It  is  per- 
fectly easy  for  birds  to  fly,  for  quadrupeds  and  insects  to  migrate,  and  for  seeds 
to  be  carried  across  this  region  at  many  points,  but  if  they  do  so  they  immedi- 
ately perish.  It  is  the  climatic  condition  which  constitutes  the  direct  barrier, 
and  these  conditions  are  the  direct  result  of  the  mechanical  obstmction  consti- 
tuted by  the  mountain  chain  referred  to.  The  heated  winds  which  sweep  across 
the  tropical  Atlantic  become  surcharged  with  moisture.  On  striking  the  shore 
the  changed  condition  disarranges  the  cloud  equilibrium  sufficiently  to  precipi- 
tate a  portion  of  this  moisture.  But  the  clouds,  thus  lightened,  as  they  sweep 
onward  do  not  pass  over  a  dry  region,  but  one  that  is  a  perfect  net-work  of 
broad  lakes  and  rivers ;  a  surface  that  at  certain  seasons  probably  presents  more 
water  than  land ;  so  the  little  disarrangement  that  has  been  caused  in  the  at- 
mospheric conditions  is  at  once  atoned  for  by  the  soaking  up  of  a  fresh  supply 
of  vapor,  which  is  again  partially  precipitated,  and  so  on;  so  that  the  transit  of 
these  clouds  across  the  Amazonian  sylvas  is  a  mere  succession  of  partial  un- 
loadings  and  loadings,  a  journey  of  equalization,  in  the  course  of  which  those 
I  On  the  evening  of  December  1, 1887,  Dr.  H.  H.  Rusby  delivered  before  the  students 
and  Alumni  of  the  Philadelphia  College  of  Pharmacy  a  very  interesting  lecture,  pro- 
fusely illustrated  with  specimens,  on  subjects  connected  with  the  researches  during  a 
sojourn  in  South  America.  From  a  stenographic  report  of  this  lecture  by  Dr.  C.  R.  ISIor- 
gan,  we  select  a  portion  relating  to  the  Bolivian  home  of  the  cinchonas,  and  intend  to 
publish  in  the  following  numbers  of  the  Jotjrnal,  several  parts  of  the  same  lecture  relat- 
ing to  other  topics. — Editor. 
