354 
ON  THE  CULTIVATION  OF  JALAP. 
The  tubers  are  sometimes  elongated,  sometimes  round,  and  always 
terminate  in  a  rootlet.  In  the  fresh  state  they  are  whitish,  almost 
inodorous,  and  full  of  a  viscid  juice,  which  has  a  peculiar  acrid 
taste.  When  collected,  the  larger  tubers  are  cut  through,  but 
the  smaller  left  entire.  As  drying  them  in  the  sun  would  pro- 
bably be  impracticable,  they  are  placed  in  a  net  and  then  hung 
over  the  almost  constantly  burning  hearth,  where  by  degrees 
they  dry,  and  by  which  process  they  almost  always  acquire  a 
smoked  appearance  and  somewhat  sooty  smell.  In  about  ten  to 
fourteen  days  the  Purga  is  dry,  and  is  then  taken  by  the  col- 
lectors, who  are  mostly  Indians,  to  Jalapa,  where  it  is  bought 
up,  and  whence  it  is  conveyed  by  way  of  Vera  Cruz  into  the 
markets  of  Europe. 
"  The  Indians  of  Chiconquiaco  are  commencing  to  cultivate 
the  Jalap  plant  in  their  gardens.  The  future  will  show  whether 
its  powers  are  in  any  degree  impaired  by  cultivation.  Cultivation 
will  afford  the  advantage  that  the  roots  may  be  collected  at  the 
most  favorable  time  of  year,  which  in  the  thick  forests  is  attended 
with  difficulty.  I  do  not  abandon  the  hope  that  Convolvulus  Ja- 
lapa may  some  day  be  planted  in  our  gardens  on  a  large  scale ; 
is  not  the  potato  a  native  of  a  similar  region  ?  The  plant  will 
scarcely  bear  the  severity  of  a  German  winter  in  the  open  air, 
but  the  spring  and  autumn  frosts  will  not,  I  think,  injure  it,  for 
it  has  to  endure  the  same  reduced  temperature  in  its  native 
home. 
"  I  now  hear  that  the  root  has  also  been  exported  from  Tam- 
pico,  which  shows  that  it  occurs  northward  of  the  mountains  of 
Chiconquiaco,  perhaps  in  the  Sierra  Madre." 
To  this  account  may  be  added  a  few  lines  extracted  from  a 
letter  received  from  a  valued  correspondent  of  my  own  in  Mexico, 
to  whom  I  am  also  indebted  for  more  than  a  hundred  living  tubers 
©f  the  jalap  plant. 
uThe  tubers  of  Jalap  require  a  deep  rich  vegetable  soil 
(debris  of  the  leaves  of  Pinus,  Quercus,  Alnus,  etc.),  and  as  they 
grow  at  an  elevation  of  from  7000  to  10,000  feet  above  the  level 
of  the  ocean,  they  can  stand  a  good  deal  of  cold  and  even  frost 
during  the  night.    In  the  daytime  from  60°  to  75°  Fahr.  is 
