12  Revision  of  the  U.  S.  Pharmacopoeia.  {Am- ^Z'imarm' 
tion  being,  when  dry,  of  a  very  dark  brown  color,  and  is  but  par- 
tially soluble  in  ether,  sp.  gr.  o  720,  which  proves  the  correctness  of 
Professor  Maisch's  supposition,  and  that  the  active  portion  of  the 
officinal  resin  is  almost  entirely  soluble  in  hot  water." 
The  above  citations  evidently  constitute  the  authority  for  the 
official  statement  regarding  the  solubility  of  this  resin  in  water,  but 
it  certainly  cannot  be  seriously  contended  that  the  method  adopted, 
heating  in  a  flask  with  successive  portions  of  water  for  days,  w7ould 
yield  accurate  determinations  of  the  solubility  of  a  product  of  vary- 
ing composition  and  subject  to  change. 
In  my  experiments  one  gramme  of  resin  was  treated  with  100  cc. 
of  boiling  water  for  ten  minutes,  the  water  then  decanted  from  the 
fused  resin  and  evaporated.  The  residue  weighed  -227  gm.  A  sec- 
ond determination  yielded  230  gm.  These  results  are  so  close  as  to 
be  comparable  and  prove  their  substantial  accuracy,  and  it  is  believed 
they  represent  the  true  solubility  of  resin  of  podophyllum  in  water. 
Another  discrepancy  appears  in  the  solvent  action  of  chloroform, 
as  stated  by  Mr.  F.  B.  Power  (American  Journal  of  Pharmacy,  1 874, 
231),  where  5  gm.  of  resin  is  stated  to  yield  to  chloroform  only  0*02 
gm.  This  is  most  likely  an  error,  as  immediately  beneath  on  the 
same  page  the  writer  states  that  2  gm.  of  the  ether  soluble  resin 
yielded  to  chloroform  1-4.  This  would  amount  to  nearly  65  per 
cent,  of  the  resin  coinciding  fairly  well  with  my  results,  70  per  cent. 
The  solubility  in  chloroform  of  the  medicinally  active  constituents 
of  the  resin  has  likewise  been  taken  advantage  of  in  the  process  of 
assay  generally  proposed. 
THE  UNITED  STATES  PHARMACOPCEIA  OF  1890. 
By  George  M.  Beringer,  A.M.,  Ph.G. 
[Continued  from  vol.  xxiii,  p.  602. ,] 
Volatile  Oil  of  Betula  is  introduced  to  distinguish  between  the  true 
oil  of  wintergreen  and  what  is  generally  sold  as  such.    The  state- 
ment unnecessarily  introduced  in  the  official  definition  that  "it  is 
identical  with  methyl  salicylate  "  is  seriously  disputed.    We  are 
aware  that  the  manufacturers  of  methyl  salicylate  make  this  claim 
which  has  been  questioned  by  disinterested  chemists  who  proposed  a 
distinguishing  test.    It  is  to  be  hoped  that  some  unprejudiced  chem- 
