Am.  Jour.  Pharm.  i 
March,  1890.  J 
Jalap  and  Jalap  Resin. 
H3 
more  difficult  crops.  That  any  specially  great  difficulties  would 
have  to  be  overcome  in  the  cultivation  of  the  jalap  plant  is  probably 
scarcely  to  be  feared,  since  it  is  stated  in  the  paper  already  quoted 
(p.  232),  that  Schiede's  consignment  of  jalap  tubers  supported  in 
the  winter  of  1829-30,  on  board  ship  in  the  Elbe,  a  temperature  of 
— 200  R.,  and  at  Munich  the  plants  did  better  in  the  cold-house, 
and  afterwards  in  the  open  air,  than  in  the  hot-house.  Even  at  that 
time  the  gardener  who  had  the  matter  in  hand  at  Cassel  recom- 
mended the  cultivation  of  jalap  in  Germany. 
Although,  however,  this  may  not  turn  out  so  simple  as  might  be 
wished,  it  may  be  inferred  from  the  few  experiments  recalled,  that 
it  must  be  practicable  somewhere  in  Europe,  by  the  cultivation  of 
the  jalap  plant,  to  render  a  service  to  medicine  and  to  make  a  good 
business. 
The  genera  Convolvulus  and  Ipomoea  are  distributed  in  warm  and 
hot  countries  especially,  to  the  extent  of  some  five  hundred  species. 
Probably  all  this  enormous  number  of  plants  contain  one  or  other 
of  the  resins  jalapin  (jalapurgin,  convolvulin)  or  orizabin  ;  possibly 
also  other  members  of  the  same  homologous  series  in  which  these 
two  resins  have  up  to  the  present  stood  alone.  Accident  has  deter- 
mined that  medicine-requiring  humanity  in  Mexico  has  lighted  upon 
these  two  species  of  Ipomoea,  I  purga  and  /.  orizabensis,  rather  than 
upon  some  other  American  species. 
Neither  in  Asia  are  there  wanting  powerfully  drastic  species  of 
Ipomoea.  Possibly  the  presumed  fraudulent  deprivation  of  the 
Mexican  jalap  may  be  successfully  combated  by  means  of  the  still 
onger  used  Ipomoea  Turpethum,  but  this  root  appears  to  me  to  be 
ess  productive.  On  the  other  hand  I  have  long  since  shown 
"  Pharmacographia,"  1st  edit.,  p.  403,)  that  from  the  seeds  of 
Ipomoea  hederacea,  Jacquin  (/.  Nil,  Roth.;  Pharbitis  Nil,  Choisy)  over 
8  per  cent,  of  resin  can  be  obtained,  which  is  identical  with  that 
from  Ipomoea  purga.  This  resin  (jalapurgin  or  convolvulin)  can  be 
removed  with  the  greatest 'ease  by  means  of  alcohol  from  the  seeds, 
after  they  have  been  freed  from  fat  and  powdered,  and  is  obtained 
nearly  pure  at  the  first  attempt.  Instead  of  the  unsightly  prepara- 
tion to  which  European  pharmacopoeias  give  prominence  under  the 
name  resina  jalapae,  the  kaladana  seeds  yield  the  same  substance 
only  slightly  colored.  This  far  better  looking  resin  obtained  a 
place  in  the  Pharmacopoeia  of  India  as  far  back  as   1868,  and 
