258  Tincture  of  Ginger  U.  S.  P.       {AmAirii?  i^s!™' 
Conclusions. 
From  the  above  it  would  appear  that  tincture  of  ginger,  the  per- 
centage of  water-soluble  solids  of  which  are  greater  than  15  per 
cent.,  can  be  prepared  from  strictly  U.  S.  P.  Jamaica  ginger,  using 
95  per  cent,  alcohol  as  the  menstruum.  This  is  confirmed  by  Lyth- 
goe  and  Nurenburg  and,  in  a  way,  by  Street  and  Morrison  who, 
although  they  consider  that  tincture  of  ginger  should  yield  less  than 
15  per  cent,  of  water-soluble  solids,  find  that  12  cinctures  of  ginger 
are  of  standard  quality,  in  which  the  average  yield  of  solids  soluble 
in  water  is  17  per  cent. 
The  per  cent,  of  water-soluble  solids  is  variable,  depending 
upon  the  length  of  time  the  water  is  allowed  to  remain  in  contact 
with  the  solids  and  also,  to  a  great  extent,  upon  the  manner  in  which 
the  solids  are  brought  in  contact  with  the  water.  If  the  water-sol- 
uble solids  requirement  serves  any  practical  purpose,  and  it  is  to  be 
retained,  the  U.  S.  P.  should  state  the  way  and  manner  in  which 
it  is  to  be  obtained,  and  also  establish  a  limit  that  can  be  met 
when  the  tinctures  are  prepared  from  the  U.  S.  P.  Jamaica  ginger 
and  95  per  cent,  alcohol. 
In  determining  the  total  solids,  the  statement  in  the  Pharma- 
copoeia should  be  changed  from  "'Evaporate  10  Gm.  of  tincture  of 
ginger "  to  "  Evaporate  about  10  Gm.  of  tincture  of  ginger  ac- 
curately weighed,"  as  the  tincture  is  volatile  and  it  is  impractical 
and  unnecessary  to  weigh  exactly  10  Gm.  Also  it  would  probably 
be  better  to  state  that  the  total  solids  should  be  dried  to  constant 
weight  at  ioo°  C.,  as  somewhat  lower  results  may  be  obtained  and 
also  more  accurate  checks  if  the  determination  is  made  in  this 
manner.  The  minimum  limit  as  well  as  the  maximum  should  be 
stated  for  the  total  solids  to  prevent  adulteration  by  dilution.  The 
following  standards  in  addition  to  qualitative  tests  for  capsicum  or 
other  pungent  substitute  would  probably  be  all  that  would  be  neces- 
sary to  prevent  adulteration  of  tincture  of  ginger  and  at  the  same 
time  show  the  product  to  be  of  a  good  quality. 
Alcohol  about   90      per  cent,  by  volume. 
Specific  gravity  about   0.82 
Non-volatile  solids,  not  more  than    1.75,  nor  less  than  1.25  per  cent. 
Analytical  Laboratories, 
Norwich  Pharmacal  Company, 
Norwich,  N.  Y. 
