AmAJp°rif  i^il!m'  )       Tincture  of  Ginger  U.  S.  P. 
255 
claims  upon,  and  in  placing  the  limit  for  water-soluble  solids  at  15 
per  cent.,  when  they  found  14.7  per  cent.,  they  have  adopted  an  ex- 
tremely narrow  limit.  When  it  is  taken  into  consideration  that 
they  are  using  a  method  which  will  show  variations  greater  than 
0.3  per  cent,  in  the  hands  of  different  operators,  as  they  themselves 
state  in  their  method,  that  "  because  of  the  gummy  character  of 
many  of  the  residues,  it  is  sometimes  difficult  to  secure  proper  con- 
tact with  the  solvent." 
In  the  same  article,  we  read  the  following :  "  34  samples  sold 
as  flavoring  extracts  and  14  sold  as  tincture  of  ginger  were  exam- 
ined, but  only  the  analysis  of  certain  ones  which  are  typical  and  a 
general  summary  of  all  samples  will  be  given.  Seven  of  the  ex- 
tracts were  classed  as  standard  composition  and  seven  as  legally 
labeled  compounds  and  twenty  as  below  standard,  or  adulterated. 
Of  the  tinctures,  12  are  of  standard  quality.  As  the  tinctures  are 
of  special  interest  to  us  an  examination  of  the  analytical  data  accom- 
pany this  article  is  advisable,  from  which  we  find  that  the  averag? 
analysis  of  these  12  standard  tinctures  is  as  follows : 
Specific  gravity   0.8371 
Alcohol  by  volume    93-33 
Total  solids   1.38 
Soluble  in  alcohol    1.30 
Soluble  in  water    0.23 
Per  cent,  of  the  total  solids  soluble  in  alcohol   96 
Per  cent,  of  the  total  solids  soluble  in  water   17 
In  one  paragraph  we  read  that  they  conclude,  from  one  sample 
of  tincture  of  ginger  prepared  by  them,  that  not  over  15  per  cent, 
of  the  solids  should  be  soluble  in  water,  and,  in  another,  that  the 
average  of  the  water-soluble  of  12  standard  tinctures  is  17  per  cent. 
This,  surely,  is  not  consistent,  to  state  that  the  water-soluble  should 
be  less  than  15  per  cent,  and  then  to  consider  as  standard  quality 
12  tinctures,  the  average  water-soluble  of  which  is  17  per  cent. 
Lythgoe  and  Nurenburg,  Journal  of  Industrial  and  Engineering 
Chemistry,  December,  191 1,  prepared  a  sample  of  tincture  of  ginger, 
using  200  Gm.  of  Jamaica  ginger  to  the  liter  and  percolated  with 
95  per  cent,  alcohol.    They  present  the  following  analysis : 
Per  Cent. 
Alcohol  by  volume    88,76 
Total  solids    1.40 
Soluble  in  alcohol    1.33 
