482  American  Pharmaceutical  Association.  {^pl^h^im.' 
the  melting  points,  titrations  of  the  samples  with  decinormal  sulphuric  acid 
volumetric  solution,  and  estimations  of  benzoic  acid  yielded  upon  saponifi- 
cation, the  author  concluded  that  none  of  the  samples  were  pure,  but  were  to  a 
greater  or  less  extent  mixed  with  apo-aconitine  and  pseudo-aconitine.  No  two 
of  the  samples  were  found  to  be  the  same.  He  urged  the  necessity  of  having 
a  definite  product  so  that  a  physician  could  know  what  he  was  ordering  and 
what  effects  to  expect. 
Professor  Prescott  thought  that,  in  view  of  the  unstable  character  of  the 
alkaloids  of  aconite  root,  a  concentrated  preparation  was  probably  the  best 
form  for  use.  He  believed  it  would  be  difficult  to  keep  the  alkaloids  in  the  free 
state,  unless,  perhaps,  with  the  aid  of  a  preservative.  He  was  in  favor  of 
Squibb's  method  of  assay  by  application  to  lips  as  the  best  known  method. 
The  work  of  our  foreign  brethren,  who  have  lately  been  investigating  aconite 
alkaloids,  came  in  for  a  share  of  attention  in  the  discussion  which  followed  the 
reading  of  the  paper. 
THE  DIGESTIVE  POWER  OF  PEPSIN. 
By  C.  C.  Sherrard. 
The  effect  of  the  amounts  of  water  and  hydrochloric  acid  given  in  the  official 
assay  of  pepsin  was  considered  in  detail.  Chairman  Dohme  thought  it  would 
be  well  to  have  the  attention  of  the  Revision  Committee  of  the  U.  S.  Pharma- 
copoeia called  to  the  results  of  this  investigation. 
STRUCTURE  OF  OUR  CHERRY  BARKS. 
By  Edson  S.  Bastin. 
An  exhaustive  study  of  the  microscopical  structure  of  our  cherry  barks  was 
the  subject  of  the  next  contribution.  This  paper  is  published  in  full  on  page 
435  of  this  issue.  Prof.  Whelpley  considered  that  the  association  owed  Prof. 
Bastin  many  thanks  for  the  means  of  so  easily  distinguishing  the  barks  of  the 
different  species.  The  same  speaker  remarked  that  the  Pharmacopoeia  directed 
only  those  barks  known  to  be  useful.  He  suggested  that  some  one  make  deter- 
minations of  the  relative  medicinal  value  of  the  barks  of  the  unofficial  species. 
ASSAY  OF  WILD  CHERRY  BARK. 
By  A.  B.  Stevens  and  J.  N.  Judy. 
In  order  to  answer  query  number  1,  "Is  the  thin,  green  wild  cherry  bark 
really  more  valuable  therapeutically  than  the  older  and  thicker  bark?"  the 
authors  made  comparative  assays  on  carefully  selected  samples  of  each  variety. 
The  results  furnished  to  the  query  a  negative  answer. 
The  method  of  estimation  was  based  upon  the  conversion  of  the  glucoside 
amygdalin  into  hydrocyanic  acid  and  a  volatile  oil  when  the  bark  was  mace- 
rated with  water;  second,  upon  the  distillation  of  the  hydrocyanic  acid  to 
separate  it  from  the  bark  ;  and  third,  upon  the  estimation  of  the  hydrocyanic 
acid,  both  volumetrically  by  titration  with  potassium  hydrate  solution  and 
gravimetrically  by  conversion  into  the  silver  compound.  The  thick  bark 
showed  from  "32  per  cent,  to  '35  per  cent.,  the  thin  bark  from  '24  per  cent,  to 
•27  per  cent,  of  hydrocyanic  acid.  These  amounts  are  much  higher  than  have 
been  reported.  The  authors  established  the  fact  that  the  methods  of  esti- 
mation formerly  employed  were  very  defective.  Messrs.  Stevens  and  Judy 
added  water,  and  continued  the  distillation  until  no  more  hydrocyauic  acid 
