ON  SOME  PRINCIPLES  OF  CONVALLAMA  MA  JAMS.  577 
tained  from  different  sources,  not  one  was  free  of  copper. 
The  presence  of  copper  is  easily  proven  ;  citron  is  cut  'into 
small  pieces  and  put  into  water  containing  some  acetic  acid  ; 
the  bright  blade  of  a  knife  is  then  immersed  in  it,  and  soon  be- 
comes covered  with  a  reddish  film.  Citron  containing  copper 
assumes  a  brownish  red  color  when  thrown  into  a  solution  of 
ferrocyanuret  of  potassium. 
It  does  not  admit  of  any  doubt  that  the  copper  is  derived 
from  the  vessels  in  which  the  citron  is  prepared ;  this  is  effected 
in  the  following  way :  the  large  fruit  of  Citrus  medica,  Risso, 
and  Citrus  decumana,  L.,  are  plucked  before  they  are  fully  ripe, 
cut  lengthwise  into  two  or  four  pieces,  and  after  the  removal  of 
the  pulpy  interior,  are  distilled  with  water  from  a  copper  kettle, 
to  gain  the  volatile  oil  which  is  sold  under  the  name  of  "  huile 
de  cedrat."  The  action  of  the  free  fruit  acid  on  the  copper  can 
be  hardly  prevented,  particularly  if  the  kettle  had  not  been  kept 
in  a  bright  state,  but  had  become  covered  with  oxide.  After 
the  volatile  oil  has  been  distilled  off,  a  certain  quantity  of  sugar 
is  added  to  the  thin  residue  containing  the  pieces  of  the  fruits, 
and  the  excess  of  water  is  evaporated. — Journal  de  Pharm. 
d'Anvers,  1859,  37.—  Wittsteiri  s  Viert.  Sehr.  viii.  451.) 
ON  SOME  PRINCIPLES  OF  CONY  ALL  ARIA  MAJALIS. 
By  G.  F.  Walz. 
Some  time  ago,  the  author  analyzed  the  lily  of  the  valley ; 
in  the  N.  Jahrbuch  f.  Pharm.  1858,  x.  145,  he  published  his  in- 
vestigations of  the  two  most  important  constituents — the  conval- 
larin,  a  crystalline  acrid  principle,  and  the  convallamarin,  which 
is  pulverulent  and  bitter. 
Preparation.  The  herb,  together  with  the  root,  is  collected 
before  or  after  flowering,  dried,  coarsely  powdered,  exhausted  by 
alcohol  of  »840  spec,  grav.,  the  green  filtrates  are  precipitated 
by  subacetate  of  lead,  the  dissolved  lead  removed  by  sulphuretted 
hydrogen  and  the  clear  filtrate  is  distilled  in  the  waterbath  to 
regain  the  alcohol.  The  residue  separates,  on  cooling,  a  mass  of 
crystals,  mixed  with  chlorophyl,  resin,  &c;  after  collecting  them 
on  a  filter,  they  are  pressed  and  treated  with  ether,  which  leaves 
