208 
ON  THE  PURGATIVE  CONVOLVULACE^l. 
4  to   5         3  to  4 
1-5  to  2 
2  to  3 
falsifications  which  are  practised  but  too  easily.  Do  we  not,  in 
fact,  see  fusiform  jalap  sold  daily,  to  the  exclusion  of  trile  jalap, 
under  the  false  name  of  "jalap  stalks,"  and  afterwards,  fusiform 
jalap  itself  held  in  check  by  this  new  arrival  of  large  finger 
jalap,  which  contains  but  two  per  cent,  of  resin. 
The  committee  represented  by  M.  Marais  regret  that  a  sample 
of  the  fusiform  jalap,  examined  by  the  author  of  the  thesis,  had 
not  been  sent  to  them,  and  which  had  produced  such  an  unpre- 
cedented yield  of  resin. 
Table  of  the  Comparative  Quantities  of  Resin  yielded  by  Different 
Varieties  of  Jalap  : — 
M.  Andouard.  Committee. 
Per  cent.  Per  cent. 
Jalap — Tuberous  or  Officinal  {Exogonium purga)    12  to  14      16  to  17 
"       Fusiform  (Ipomea  orizabensis)    .       .    10,  14  to  20        9  to  10 
"  Tampico  
"       Large  Finger  (digite)  . 
"       Small  Finger  .... 
"       Black,  ree  d,  by  way  of  Vera  Cruz 
(origin  unknown)    ....  8  to  10 
In  regard  to  the  discrepancies  in  these  results,  M.  Marais 
doubts  the  similarity  of  the  tuberous  and  fusiform  jalap  ex- 
amined ;  and,  besides,  believes  that  a  variation  in  the  mode  of 
extracting  the  resin  must  have  occurred,  and  then  puts  the  ques- 
tion whether,  in  equal  doses,  these  resins  have  the  same  purga- 
tive property.  M.  Andouard  says  "yes,"  for  the  two  principal 
kinds  at  least.  The  Committee  have  not  been  able  to  fully 
respond  to  this  question,  as  the  specimens  placed  in  the 
hands  of  several  hospital  physicians  could  not  be  used,  owing  to 
the  epidemic  cholera  prevailing.  They  can  say,  however,  that 
one  of  the  members  took  the  resins  in  doses  of  25  to  40  centi- 
grams, (3J  to  5|  grains),  and  found  the  effect  of  the  tuberous 
jalap  to  that  of  the  fusiform  in  the  ratio  of  5  to  3.  The  resins 
of  the  other  varieties  were  not  tried. 
SCAMMONY. 
M.  Marais  says  that  this  part  of  the  thesis  did  not  offer  much 
that  is  new,  regrets  that  M.  Andouard  has  not  been  in  a  position 
to  prosecute  his  researches  more  closely  into  the  value  of  the 
varieties  of  scammony,  and  hopes  that  he  will  have  the  heart  to 
take  hold  of  the  task  with  so  good  an  object  in  view. 
