492  Copper  in  Preserved  Vegetables.  {A%JcT^?arm' 
makes  them  unmarketable.  The  author  expressed  the  opinion  that 
preserves  of  this  kind  containing  copper  can  be  eaten  without  injury 
to  health.  He  stated  that  he  had  found  by  experiment  20  to  24 
milligrams  of  copper  sufficient  to  give  the  desired  green  color  to  a 
kilogram  of  preserves.  He  therefore  recommended  that  this  quantity 
of  copper  should  be  considered  allowable  and  unobjectionable  for 
the  coloring  of  preserves. 
Med.  R.  Karsch  (Speyer)  stated  that  what  was  done  in  Germany 
was  based  upon  the  practical  experience  of  France,  and  he  thought 
the  same  limits  might  be  set  up  there  as  in  that  country. 
Herr  Barth  (Rufach)  mentioned  a  case  in  Brunswick  in  which  a 
preserve  manufacturer  had  been  acquitted  on  the  basis  of  a  medical 
opinion.  The  question  involved  in  the  use  of  copper  salts  was  not 
one  of  dressing  up  decayed  food  material,  but  of  imparting  a  color. 
In  the  case  of  some  preserves,  peas  for  instance,  a  vegetable  pig- 
ment can  be  used  in  the  place  of  a  copper  salt,  but  in  others,  such  as 
beans,  it  could  not. 
Herr  Barth  communicated  some  experiments  made  with  wine, 
containing  copper  which  had  been  derived  from  the  compounds  used 
as  dressing  against  Peronospora.  Cows  were  given  up  to  8  grams 
of  sulphate  of  copper  daily  without  any  injurious  effects  being 
observed. 
Med.  R.  Merkel  (Nuremberg)  uttered  a  warning  against  the 
results  of  such  experiments  on  animals  being  applied  to  men.  It  was, 
however,  a  fact  that  the  cases  of  chronic  copper  poisoning  recorded 
in  forensic  literature  could  not  support  strong  criticism  ;  but,  on  the 
other  hand,  it  could  not  be  said  that  there  was  no  danger.  Chronic 
copper  poisoning  occurring  among  workers  in  copper  and  bronze 
had  not  yet  come  to  his  knowledge.  In  his  opinion  the  meeting 
was  not  yet  in  a  position  to  come  to  a  decision  upon  the  question. 
Herr  Kayser  (Nuremberg)  also  argued  against  going  to  the 
extreme  on  the  one  hand  of  holding  that  the  presence  of  a  copper 
compound  such  as  verdigris  in  an  alimentary  substance  was  injurious 
to  health  in  the  highest  degree,  or  on  the  other  that  the  presence  of 
a  certain  amount  of  copper  in  a  food  was  of  no  consequence. 
Med.  R.  Egger  (Landshut)  called  attention  to  the  fact  that  up  to 
that  time  no  one  had  said  where  the  danger  of  copper  in  preserved 
vegetables  begins. 
The  author  replied  that  the  copper  compounds  formed  in  the  pre- 
