'^"^May^iss?™"}   Analytical  Researches  and  Investigations.  221 
folded  silk  paper^  which  is  then  covered  by  the  reagent  paper,  and 
kept  in  position  by  allowing  a  book  or  other  object  to  rest  upon  it. 
The  reaction  is  rendered  evident  upon  the  silk  pa23erj  without  the 
direct  contact  of  the  metal,  and  after  a  few  minutes  a  deposit  of  silver 
is  formed  upon  the  paper,  and  which  corresponds  to  the  length  of  the 
copper  plate  which  has  been  immersed  in  the  liquid.  By  means  of 
this  extremely  sensitive  reaction  mercury  may  be  detected  in  the  blood 
of  small  animals  which  have  been  slowly  destroyed  by  exposure  to- 
mercurial  vapors,  as  also  with  certainty  in  the  urine  of  syphilitic 
persons,  who  have  been  subjected  to  mercurial  treatment. — Ibid.,  No. 
18,  p.  132,  1882,  from  Journ.  de  med.  de  Bordeaux,  p.  339,  1881. 
Distinction  betiveen  Cadaver  and  Plant  Alkaloids.  By  H.  Beckurts.. 
— Since  the  knowledge  of  the  fact  that  in  dead  bodies,  through  the  influ- 
ence of  putrefaction,  alkaloidal  bodies — scepticines,  or  the  ptomaines  of 
Selmi,  may  be  formed,  which,  in  their  chemical  reactions,  show  a 
behavior  quite  analogous  to  that  of  the  plant  bases,  the  attempt  has 
been  repeatedly  made  to  discover  characteristic  points  of  distinction 
between  them. 
General  reactions,  by  means  of  which  it  may  be  readily  and  certainly 
decided  whether  a  plant  alkaloid  or  one  of  the  so-called  ptomaines  is 
in  question,  have  remained  as  yet  unknown.  The  discovery  of  such 
must  also  remain  for  the  present  at  least  problematical,  as  long  as  the 
knowledge  of  the  chemical  nature  of  the  ptomaines  remains  so  deficient, 
and  when  under  the  latter  designation  an  entire  group  of  compounds 
is  comprehended,  the  members  of  which,  apparently,  formed  under  the 
same  conditions,  exert  a  varying  physiological  action,  and  probably 
stand  also  in  very  loose  chemical  connection.  Our  interest,  therefore,, 
must  be  attracted  the  more  to  a  recently  puplished  essay  of  Brouardel 
and  Boutmy  ('X'omptes  Rendus,''  1881,  p.,  92,  1056),  wherein  they 
maintain  to  have  found  in  potassium  ferridcyanide  a  reagent  which 
will  distinguish  these  two  classes  of  bodies.  Plant  alkaloids,  according 
to  the  statements  of  these  chemists,  do  not  change  this  salt,  whereas  the 
ptomaines  reduce  the  same  at  once  to  potassium  ferrocyanide,  ^v^hich 
may  be  recognized  by  a  precipitate  of  Prussian-blue  on  the  addition  of 
a  ferric  salt.  An  exception  to  the  rule  is  morphine  and  veratrine,  of 
which  the  former  has  a  strong  reducing  action,  the  latter  to  a  lesser 
extent. 
The  importance  of  this  statement  for  forensic  chemistry  induced  the 
author  to  repeat  the  related  experiments,  but  only  with  regard  to  the 
