Am.  Jour,  Pharm.  "I 
Jan.,  1883.  j 
Researches  on  the  Jalaps. 
33 
which  the  small  roots  of  jalap  would  be  generally  more  rich  in  resin 
than  the  large  tubercules  from  the  same  plant.  This  does  not  agree 
with  what  is  revealed  by  the  microscopic  investigation,  and,  moreover, 
is  not  in  accord  with  the  amounts  found  by  M.  Guibourt.  Would 
not  M.  Andouard  consider  as  "  small  roots  the  slightly  tuberized 
fragments  which  are  met  with  in  the  debris,  which  are  derived  from 
subterranean  stems  and  which  in  fact  contain  much  resin  ? 
With  the  object  of  adding  sometliing  new  to  the  results  already 
known,  I  have  extracted  the  resin,  by  the  Codex  process,  from  nine 
specimens  of  jalap.  In  order  to  utilize  the  products  of  the  aqueous 
macerations  involved  in  this  process,  I  prepared  extracts  evaporated 
in  a  water-bath  to  a  pilular  consistence,  of  which  I  have  given  the 
yield.  ^ 
Resin  Aqueous 
dried  at  Extract. 
100°.  Per 
Per  cent. 
cent. 
I.  Type  Specimens  of  Jalap. 
Supplied  by  the  "  Pharmacia  Centrale." 
Tuberous  or  official  jalap,  . 
,  12-5 
88 
Light  jalap  (small  specimens),  . 
2-0 
35 
Digitate  major  jalap, 
7-0 
12 
Digitate  minor  jalap. 
9-0 
11-5 
II.  Picked  Commekcial  Jalap. 
No.  1,  . 
12-5 
35 
No.  2, 
10-5 
33 
No.  3,       .  . 
7-5 
23 
No.  4, 
8-0 
17 
III.  DEBKIS,         .                 .                 .  . 
,  8-5 
27 
It  follows  from  the  investigation  of  different  authors  that  j.alap 
owes  its  purgative  properties  to  two  homologous  resinous  glucosides, 
convolvulin  and  jalapin.  I  have,  however,  nowhere  met  with  mention 
of  clinical  experiments  made  with  the  pure  glucosides.  Might  there 
not  be,  if  not  an  alkaloid,  as  alleged  by  Hume,  at  least  a  principle 
other  than  the  resinous  glucosides,  and  which  has  hitherto  escaped 
analysis  ?  If  the  opinion  of  La  Maout  and  Decaisne  is  to  be  accepted 
(Traite  general  Botanique)  the  resin  of  the  Convolvulacese  owes  its 
purgative  properties  only  to  the  aroma  which  accompanies  it,  for  the 
rhizomes  lose  them  when  powdered  and  exposed  for  a  long  time  to  the 
air,  although  they  preserve  the  purely  resinous  principle.  The  odorous 
oleaginous  substance  which  floats  at  the  top  towards  the  end  of  the 
distillation,  when  nearly  all  the  alcohol  is  removed  from  the  tincture 
3 
