"^""•oSMim^''™'}        Mayer's  Reagent  for  Alkaloids.  487 
and  even  in  them  it  was  almost  insigoificant,  but  that  there  was  a  loss 
of  about  four  per  cent,  of  water,  which  is  almost  the  equivalent  of  one 
molecule. 
A  sample  which  had  been  kept  in  a  glass-stopped  bottle  for  several 
vears  was  also  examined  and  found  to  have  the  composition  of  the 
officinal  salt ;  the  bottle  had  been  frequently  opened  for  the  removal 
of  a  portion  of  its  contents,  and  at  the  time  of  the  examination  was 
nearly  empty. 
Precipitated  sulphate  of  iron,  then,  is  of  constant  composition,  and  is 
the  same  as  the  large  crystals ;  it  keeps  well  in  glass-stopped  bottles, 
but  loses  water,  and  is  slowly  oxidized  on  exposure  to  the  atmos- 
phere. 
Philadelphia,  July  16,  1888. 
MAYER'S  REAGENT  FOR  THE   ESTIMATION  OF 
ALKALOIDS.  1 
By  H.  W.  Snow,  Ph.  C. 
Two  years  ago  Dr.  A.  B.  Lyons  presented  to  this  Association  a  pa- 
per on  the  estimation  of  alkaloids  by  Mayer's  Reagent,  which  is,  I 
believe,  the  most  exhaustive  and  thorough  paper  ever  published  on 
this  subject.  In  fact,  it  is  my  opinion  that  comparatively  little  re- 
mains to  be  said ;  at  least  so  far  as  immediately  practical  results  are 
concerned,  and,  consequently  I  feel  some  hesitation  in  travelling  again 
over  the  same  ground,  particularly^  as  the  experiments  performed  by 
me  have  been  far  more  limited  in  number  than  those  from  which  Dr. 
Lyons  drew  his  conclusions.  It  is,  therefore,  well  to  say  at  once  that 
this  paper  is  intended  more  particularly  to  draw  attention  to  a  method 
of  interpreting  the  results  of  titrations,  rather  than  with  the  expecta- 
tion of  advancing  any  new  and  hitherto  unknown  facts  bearing  on  the 
use  of  this  reagent.  In  your  proceedings  of  last  year  in  connection 
with  the  assay  of  ipecac,  and  again  at  a  later  date,  in  connection  with 
the  assay  of  aconite  in  the  New  Idea,  I  gave  tables  for  the  interpreta- 
tion of  the  results  of  titrations  of  the  alkaloids  contained  in  those 
drugs,  and  it  is  these  tables,  somewhat  extended  and  similarly  applied 
^  Eead  before  the  Michigan  State  Pharmaceutical  Association,  at  its  meeting 
in  Detroit,  September,  1888,  and  communicated  by  the  Author. 
