EXAMINATION  OF  DEPOSIT  FROM  TINCTURA  RHEI.  149 
phanic  acid.  The  small  amount  of  precipitate  shows  that  the 
tincture  would  not  deteriorate  within  a  reasonable  time  for  dis- 
pensing the  same. 
Before  ascertaining  that  the  deposit  bore  so  small  a  propor- 
tion to  the  matter  held  in  solution,  I  had  prepared  four  samples 
of  tinctures,  using  for  No.  1  the  officinal  formula ;  No.  2,  the 
rhubarb  in  moderately  coarse  powder,  2  parts  alcohol  and  1  part 
water  ;  No.  3,  rhubarb  in  fine  powder  and  stronger  alcohol ; 
No.  4,  rhubarb  in  moderately  coarse  powder,  2  parts  alcohol,  1 
part  water,  and  1  part  glycerine. 
The  materials  in  each  percolator  appeared  to  be  exhausted, 
and  were  nearly  tasteless  ;  the  tinctures  2  and  4  resembling  the 
officinal  preparations  in  appearance,  No.  4  being  sweet,  and 
having  the  taste  of  rhubarb  somewhat  masked.  No.  3,  or  alco- 
holic tincture,  was  of  a  light  wine  color. 
These  four  tinctures  w^ere  placed  on  a  shelf  in  the  saleroom, 
subject  to  the  same  light  and  treatment  as  in  the  first  experi- 
ment. Within  a  few  days  a  deposit  commenced  forming  in  each, 
— much  the  least  in  No.  3, — and  at  the  expiration  of  eight 
months  a  yellow  deposit  covered  more  or  less  thickly  the  bottom 
of  each  bottle. 
Each  tincture  was  filtered  through  a  tared  filter,  precipitates 
washed  with  distilled  water,  dried  until  they  ceased  to  lose 
weight,  and  weighed. 
Deposit  in  No.  1,  light  yellow  color,      4*5  grs.  to  pint. 
"  "   2,  yellowish-brown  color,2-4  " 
"  "    3,  reddish  "    2-0  " 
"  "  4,  yellow  "    4-4  " 
These  deposits  were  examined  only  qualitatively.  Nos.  1  and 
4  gave  indications  of  considerable  chrysophanic  acid,  No.  2  much 
less,  and  No.  3  but  a  trace. 
It  is  evident  that  a  tincture  made  with  the  stronger  alcohol 
will  retain  all  the  active  principles  in  solution,  or,  if  so  much 
alcohol  would  be  objectionable,  a  tincture  made  with  two  parts 
alcohol  and  one  part  water  would  be  nearly  as  permanent. 
Middletown,  N.  Y.,  Sept.,  1869. 
— Proe.  Amer.  Pharm.  Assoc. ^  1869. 
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