322  ON  VERATRUM  VIRIDE. 
troyounces  of  the  root  in  powder  moistened  with  twelve  fluid- 
ounces  of  alcohol,  was  introduced  into  a  percolator,  and  alcohol 
gradually  poured  upon  it  until  a  pint  of  tincture  had  passed. 
This  was  set  aside,  and  the  percolation  continued  until  five  pints 
more*  of  tincture  were  obtained.  This  was  distilled  to  one  pint 
and  mixed  with  the  reserved  tincture. 
To  the  fluid  extract  (which  was  slightly  acid  to  test  paper) 
sufficient  acetic  acid  was  added  to  give  a  distinct  acid  reaction, 
and  the  extract  poured  into  one-half  gallon  of  water  with  con- 
stant agitation.  The  mixture  was  allowed  to  stand  for  twenty- 
four  hours,  when  the  resin  was  collected  on  a  cloth  filter.  After 
distilling  the  alcohol  from  the  solution,  evaporation  was  con- 
tinued until  it  was  reduced  to  one  pint ;  it  was  then  filtered 
through  paper  to  separate  the  remaining  resin,  two  ounces  of 
alcohol  added,  and  carbonate  of  soda  to  decided  alkaline  reaction. 
The  addition  of  alcohol  was  found  advantageous  in  preventing 
the  precipitation  of  coloring  matter  with  the  impure  principles. 
On  adding  the  carbonate  of  soda  to  slight  alkaline  reaction  the 
solution  became  dark  and  opaque,  farther  addition  of  the  car- 
bonate of  soda  increased  the  precipitation,  and  the  solution  as- 
sumed a  clear  wine-red  color. 
The  precipitate  was  collected  on  a  filter,  washed  slightly,  dried, 
dissolved  in  alcohol  and  digested  with  purified  animal  charcoal. 
The  alcoholic  solution  left,  on  evaporation,  a  dark  brown  resin  ; 
this  residue  was  dried  and'  treated  with  water  acidulated  with 
sulphuric  acid,  using  a  gentle  heat  to  promote  the  solution.  On 
.cooling,  the  solution  became  turbid  and  deposited  a  floccu- 
lent  precipitate,  which  proved  to  be  chiefly  coloring  matter. 
When  cold,  the  solution  was  filtered,  and  precipitated  by  car- 
bonate of  soda.  The  precipitate  was  collected  on  a  filter  and 
washed  till  the  filtrate  passed  without  color,  when  it  was  again 
dissolved  in  water  acidulated  with  sulphuric  acid  and  digested 
with  animal  charcoal  on  a  water  bath. 
[On  adding  to  a  portion  of  this  slightly  acid  solution  in  a  test 
tube  an  equal  volume  of  alcohol,  to  ascertain  if  any  lime  salt 
was  present  from  the  charcoal,  of  the  purity  of  which  I  was  not 
confident,  the  solution  became  very  turbid,  and,  on  warming, 
deposited  a  copious  precipitate.    Examination  of  the  clear  fluid, 
