LACTUCARIUM  AND  ITS  PREPARATIONS. 
227 
description  of  it  in  the  books  at  hand  ;  it  is  evident  that  although 
it  comes  from  the  continent  of  Europe,  its  shape  is  that  resulting 
from  the  process  said  to  be  pursued  in  the  neighborhood  of  Edin- 
burgh for  the  collection  and  drying  of  the  juice. 
The  third  variety  is  called  Thridace,  or  French  lactucarium. 
This  is  evidently  not  collected  from  incisions  in  the  living  plant 
as  the  other  varieties,  but  is  an  extract  obtained  by  the  evapo- 
ration of  the  expressed  juice  of  the  stalks  gathered  at  the  season 
of  their  maturity  ;  it  has  a  darker  color  than  either  of  the  other 
varieties,  is  deliquescent,  and  generally  occurs  in  fragments  of 
cakes,  as  though  dried  upon  a  flat  surface.  The  botanical 
sources  of  these  several  kinds  of  lactucarium  are  as  obscure  as 
their  commercial  history;  as  far  as  we  know  there  is  no  cer- 
tainty which  of  them  are  derived  from  Lactuea  virosa,  which 
from  L.  sativa,  and  whether  any  of  them  are  derived  from  the 
L.  altissima  as  recommended  by  M.  Aubergier  of  Clermont,  or 
from  other  botanical  sources. 
The  price  of  the  English  variety  is  maintained  at  about  $1.25 
per  ounce,  while  the  German  article,  which  is  largely  imported, 
is  sold  at  less  than  half  that  price,  and  the  French,  though  very 
little  in  demand,  is  still  lower.  The  general  impression  is  in 
favor  of  the  superiority  of  the  English,  and  we  are  informed  that 
this  obtains  even  on  the  continent  of  Europe,  while  the  French 
thridace  is  little  used,  except  as  a  domestic  expectorant  remedy. 
The  experiments  we  have  tried  aim  at  determining  proxi- 
mately the  relative  value  of  the  two  kinds  designated  as  German 
and  English,  at  the  same  time  that  it  has  been  a  leading  object 
to  find  out  the  best  mode  of  preparation.  Omitting  any  details 
which  do  not  tend  directly  to  elucidate  one  or  other  of  these 
points  we  note  the  following  results.  English  Lactucarium  by 
thorough  exhaustion  with  diluted  alcohol  furnished  a  bitter  tinc- 
ture, which  on  evaporation  yielded  44  per  cent,  of  extract  of  a  red- 
dish brown  color,  of  intensely  bitter  taste,  reminding  of  the  drug ; 
this  was  not  wholly  soluble  either  in  water,  diluted  alcohol,  or 
strong  alcohol.  German  Lactucarium  yielded  by  the  same 
treatment  36  per  cent,  of  extract  of  a  somewhat  lighter  brown 
color,  equally  bitter  with  a  heavier  narcotic  odor  and  with  a 
consistence  more  distinctly  resinous  and  even  brittle. 
By  strong  alcohol  the  German  yielded  very  nearly  50  per 
