294 
Atropine  Per  iodides  and  Iodomer  curates.  {AmjS 
Dr.  E.  H.  Squibb  has  been  kind  enough  to  call  the  writer's  atten- 
tion to  some  statements  in  the  paper,  that  appear  as  if  it  was  inferred 
that  the  officinal  plaster  could  be  made  from  the  root  as  well  as  from 
the  leaf,  and  that  the  alkaloidal  strengths  of  the  first  three  samples 
of  the  table  (p.  1 88),  from  04  to  0-6  per  cent.,  were  regarded  as  rep- 
resenting the  standard  of  the  U.  S.  Pharmacopoeia.  There  was  no 
intention  to  convey  such  an  impression,  for  a  strictly  officinal  plaster 
can  be  made  only  from  the  leaf  and  with  a  vehicle  differing  consider- 
ably from  the  rubber  compositions  employed  by  all  manufacturers. 
The  writer  made  use  of  the  expression,  "  U.S. P.  standard  of  strength," 
which  is  rather  vague  in  this  case,  as  no  standard  is  set  except  that 
of  a  definite  quantity  of  belladonna  leaf  containing  a  variable  per  cent, 
of  alkaloids.  In  using  this  expression  the  writer  left  out  of  consid- 
eration the  source  of  the  alkaloids,  meaning  simply  a  plaster  having 
an  alkaloidal  strength  equal  to  the  average  alkaloidal  strength  of 
good  belladonna  leaf,  but  not  necessarily  made  from  leaf.  But,  since 
experience  has  shown  the  average  to  be  between  0  3  and  0-4  per 
cent.,  a  plaster  offered  as  officinal,  or  as  a  substitute  for  the  officinal, 
should  not  contain  less  than  0-3  per  cent,  of  alkaloids,  which  is  also 
the  opinion  of  Dr.  Charles  Rice. 
It  is  desired  to  correct  a  misstatement  as  to  the  authorship  of  the 
method  of  assay  which  has  been  employed  in  this  work.  Through 
a  misconception  it  was  credited  to  Mr.  S.  W.  Williams,  Ph.C,  and 
Mr.  C.  E.  Parker,  Ph.C,  as  joint  authors,  whereas  it  was  devised  in- 
dependently by  Mr.  Parker,  but  published  in  1890  by  Mr.  Williams, 
and  since  that  time  modified  and  improved  by  Mr.  Parker.  The 
writer  herewith  apologizes  to  Mr.  Parker  for  the  error. 
New  York  College  of  Pharmacy,  May  13,  1898. 
ATROPINE  PERIODIDES  AND  IODOMER.CURATES. 
It  has  been  known  for  a  long  time  that  in  solutions  of  atropine 
salts,  as  in  those  of  the  salts  of  most  other  alkaloids,  a  solution 
of  iodine  in  potassium  iodide  gives  an  insoluble  precipitate.  The 
nature  of  this  precipitate  has  so  far  as  we  know  not  been  thoroughly 
^The  Journal  of  the  American  Chemical  Society,  May,  1898. 
2  In  the  work  of  Research  Committee  D,  Section  II,  Committee  on  Revision  of  the  Pharma- 
copoeia of  the  United  States. 
BY  H.  M.  GORDIN  AND  A.  B.  PRESCOTT.2 
I.  ATROPINE  ENNEAIODIDE. 
