Am'Ap°rii?  f£fm'  )       Tincture  of  Ginger  U.  S.  P.  257 
These  results  would  indicate  that  the  Jamaica  ginger  met  the 
U.  S.  P.  requirements  in  every  particular.  The  alcohol  used  in 
the  percolating  of  the  ginger  contained  94.9  per  cent,  by  volume  of 
absolute  alcohol.  The  specific  gravity  of  the  tincture  made  from 
this  ginger  was  0.8173  and  it  contained  88.5  per  cent,  of  alcohol  by 
volume.  For  the  determination  of  the  water-soluble  solids,  4  sam- 
ples of  approximately  10  Gm.  each  were  evaporated  to  dryness  on 
the  steam  bath  and  dried  in  desiccator.  The  U.  S.  P.  directs  that 
10  Gm.  be  used,  but  as  it  is  out  of  the  question  to  weigh  accurately 
exactly  10  Gm.  of  a  volatile  substance  like  tincture  of  ginger,  about 
10  Gm.  were  taken  in  each  case.  The  following  are  the  results 
obtained  for  total  solids  from  these  four  samples : 
1.  1.80  per  cent. 
2.  1.77  per  cent. 
3.  1 .8 1  per  cent. 
4.  1.85  per  cent. 
In  addition  two  other  samples  were  evaporated  to  dryness  on 
the  steam  bath  and  then  dried  in  the  oven  to  constant  weight  at  ioo° 
C.  and  gave  the  following  results : 
5.  1.74  per  cent. 
6.  1.76  per  cent. 
To  sample  No.  1  20  Cc.  of  water  were  added  and  the  solids 
thoroughly  rubbed  with  a  rubber-tipped  glass  rod  to  bring  the  sticky 
mass  of  solids  in  contact  with  the  water.  The  water,  after  remain- 
ing on  the  ginger  solids  for  five  minutes  was  removed,  filtered 
through  9  Cm.  filter  and  the  first  two  or  three  Cc.  rejected. 
Sample  No.  2  was  treated  in  the  same  manner  as  No.  1  with  the 
exception  that  the  water  was  allowed  to  remain  in  contact  with  the 
solids  for  15  minutes,  No.  3  for  1  hour  and  30  minutes  and  No.  4 
for  2  hours  and  30  minutes.  10  Cc.  of  the  filtrates,  from  each  of 
the  samples  were  transferred  to  a  tared  evaporating  dish  and  evap- 
orated to  dryness,  dried  to  constant  weight  at  ioo°  C.  and  the  fol- 
lowing water-soluble  percentages  obtained. 
1.  16.7  per  cent. 
2.  18.8  per  cent. 
3.  22.9  per  cent. 
4.  21.5  per  cent. 
