Am.  Jour.  Phartn. ) 
Juue,  1883.  J 
Essence  from  Gi-een  Ginger. 
313 
U.  S.  p.,  1870.  U.  S.  P.,  1880. 
L.  H.  m. 
One  grain  of  opium  is  contained  in  12-8  11-43  10'74  11.04  min. 
10  njinims  represent  powdered  opium,       '781         '875      '931       -917  grs. 
It  is  obvious  that  the  difference  would  be  still  less  if  the  new  tinc- 
ture had  been  measured  at  our  average  summer  temperature.  Owing 
to  the  larger  amount  of  water  contained  in  the  deodorized  tincture  of 
opium,  this  represents  one  grain  of  opium  in  10*5  minims. 
Besides  the  above  a  considerable  number  of  the  tinctures  of  the 
U.  S.  P.,  1870,  have  been  weighed;  on  obtaining  similar  determina- 
tions made  with  the  corresponding  preparations  of  the  U.  S.  P.,  1880, 
the  subject  may  perhaps  be  discussed  again,  doubtless  leading  to  the 
same  conclusion,  that,  with  very  few  exce])tions,  the  changes  are  such 
that  the  ordinary  or  average  dose  is  scarcely  affected.  That  the  recog- 
nition by  the  Pharmacopoeia  of  the  high  commercial  quality  of  pow- 
dered opium  does  not  influence  the  relative  strength  of  the  liquid 
opium  preparations  has  been  shown  before.  (See  ''Am.  Jour.  Phar.," 
1883,  p.  55.) 
NOTE  ON  ESSENCE  FKOM  GREEN  GINGER.^ 
By  C.  Symes,  Ph.D. 
The  increased  use  of  ginger  by  manufacturers  of  mineral  waters 
and  others,  of  late  years,  has  created  a  demand  for  a  ''  soluble  essence," 
i.e., an  essence  which,  when  mixed  with  water,  causes  little  or  no  opacity 
therein. 
Dr.  Thresh's  scientific  investigation  of  the  constituents  of  this  rhi- 
zome, particularly  of  the  nature  of  its  resinous  constituents,  added 
considerably  to  our  knowledge  of  its  composition.  But  strange  to 
say,  the  process  devised  by  him^  on  the  basis  of  this  investigation,  for 
the  preparation  of  a  soluble  essence  did  not  give  (to  my  mind)  very 
satisfactory  results.  Indeed,  Dr.  Thresh  has  since  testified  to  the  supe- 
riority of  an  essence  produced  by  another  maker. 
It  would  seem,  therefore,  that  the  field  is  still  open  for  the  appli- 
cation either  of  science,  or  the  results  of  experience.  The  contri- 
bution I  have  to  offer  this  evening  is  a  simple,  short,  and  practical  one. 
Many,  Indeed  most,  drugs  deteriorate  by  age,  whilst  some  few,  such  as 
R/iamnus  Frangula  bark,  are  said  to  improve  as  they  grow  older,  at 
least  to  a  certain  point.    Now,  it  occurred  to  me,  that  the  nature  and 
*  Resd  at  an  Evening  Meeting  of  the  Pharmaceutical  Society,  April  4, 1883. 
^'See  "Amer.  Jour.  Pliar.,"  1878,  p.  494. 
