344  Lactucarium  from  Lactuca  Canadensis.  \^m^]^xm~ 
sis,  or  e.longata,  had  a  flat,  sweetish  taste  and  contained  mannit,  etc.,  but 
no  bitter  principle. 
In  September,  1867,  Prof.  Maisch  commenced  a  series  of  experi- 
ments upon  the  plant,  and  upon  the  personal  observation  then  made,  as 
well  as  the  reports  of  Doctors  DaCosta  and  Muller,  of  this  city, 
rested  convinced  that  the  plant  did  contain  a  bitter  principle  and  did  pos- 
sess decidedly  medicinal  properties,  and  that  Aubergier  had  perhaps 
improperly  conducted  his  experiments,  possibly  using  the  expressed 
juice  of  the  plant,  which,  according  to  Prof.  Maisch  (vide  "American 
Journal  of  Pharmacy,"  1869,  page  145),  has  a  flat,  sweetish  taste. 
Four  drachms  of  the  milk-juice  collected  in  September  and  October 
were  exhausted  upon  a  filter  with  boiling  alcohol.  Eight  ounces  of 
filtrate  were  obtained,  passed  through  animal  charcoal  and  concentrated 
by  spontaneous  evaporation,  when  inodorous  and  tasteless  needles  were 
obtained,  which  melted  at  about  I75°F.  and  on  cooling  congealed  to 
a  granular  mass.  They  were  evidently  lactucerin  On  still  further 
evaporating  the  mother  liquor  and  adding  to  it  water,  a  whitish  precipi- 
tate was  produced,  from  which  the  aqueous  liquor  was  thoroughly 
drained.  On  dissolving  the  precipitate  in  boiling  alcohol  and  evaporating 
the  solution  spontaneously,  more  of  the  tasteless  needles  were  obtained, 
and  pale-brownish  bitter  scales,  which  were  evidently  impure  lactucin. 
The  aqueous  mother  liquor  was  precipitated  by  basic  acetate  of  lead, 
and  both  the  precipitate  and  the  filtrate  were  freed  from  lead  by  sul- 
phuretted hydrogen.  On  evaporating  the  solutions,  brownish  amorphous 
masses,  having  a  bitter  taste,  were  left,  corresponding  to  the  lactucic 
■acid  and  lactucopicrin  of  the  European  lactucarium. 
Lactucerin  is  in  colorless  needle-shaped  crystals,  either  united  in 
stellate  groups  or  crossing  and  overlapping  each  other  ;  tasteless,  solu- 
ble in  boiling  alcohol,  petroleum  benzin,  ether,  chloroform,  and  slightly 
soluble  in  cold  alcohol  ;  insoluble  in  water.  If  heated  to  above  its 
melting  point  (i75°F.),  it  volatilizes  slowly.  Sulphuric  acid  chars  it  ; 
nitric  acid  has  no  effect  unless  heated. 
Lactucin  is  insoluble,  or  nearly  so,  in  water  ;  soluble  in  alcohol  and 
acetic  acid.  When  pure  and  not  exposed  to  much  heat,  the  lactucin 
is  in  scales  of  a  dull-white  cast ;  under  the  microscope  presents  a  rug- 
ged surface,  slightly  tinged  with  a  reddish-brown  color.  From  my 
experience,  I  am  inclined  to  think  that  if  the  scales  are  heated  in  solu- 
tion for  some  time,  they  will  not  form  again  very  readily  and  are 
