^'"'Fe'irisss^™'}        Purification  of  Carbon  Bisulphide.  91 
Oxalate  of  HydroGinchonidlne  (C,gH24N20).,,  C2H2O4,  is  obtained  by 
precipitating  the  hot  aqueous  solution  of  the  hydrochlorate  by  means- 
of  oxalate  of  ammonium,  Avhereby  it  separates  upon  cooling  in  small^ 
colorless,  shining  anhydrous  needles. 
The  neutral  sulphate  crystallizes  with  7  (or  8  ?)  molecules  of  water^ 
but  effloresces  very  readily ;  the  acid  sulphate  crystallizes  with  4  mole- 
cules of  water. — Archiv  der  Pharm.  Bd.,  xvii,  p.  860,  from  Lieblg's 
Ann.  Chem.y  204,  p.  1. 
A  Method  for  the  Separation  of  Picrotoxin  from  its  Solutions  as  an 
Insoluble  Salt.  By  R.  Palm. — The  author  finds  picrotoxin  to  be  com- 
pletely precipitated  from  its  solution  by  ammoniacal  basic  lead  acetate. 
By  the  decomposition  of  the  lead  precipitate,  suspended  in  water,  by 
means  of  hydrogen  sulphide,  and  washing  the  lead  sulphide  with  am- 
moniacal water  until  the  latter  no  longer  tastes  bitter,  a  solution  of 
picrotoxin  is  obtained,  from  which,  after  the  evaporation  of  the  solvent,, 
it  may  be  obtained  in  a  crystalline  form.  This  deportment  of  picro- 
toxin to  basic  lead  acetate  is  considered  of  value  for  its  separation  from 
beer  or  in  forensic  investigations. — Ber.  der  Deidsch.  Ch.  Ges.,  No.  16,, 
1882,  p.  2758,  from  Rep.filr.  Analyt.  Chem.,  1882,  pp.  265-267. 
l^he  Determination  of  the  Melting  Point  of  Fats. — Kratschmer  con- 
ducts this  experiment  by  bringing  the  substance  to  be  tested  into  a  capil- 
lary tube,  placing  a  drop  of  mercury  upon  it,  and  then  sealing  the  upper 
end  of  the  tube.  At  the  moment  when  the  body  melts,  the  drop  of 
mercury  sinks.  The  experiment  can  be  repeated  as  often  as  desired 
with  the  same  specimen. — Ibid.,  from  ZeiUehrift,  fur  Analyt.  Chem.,  21,, 
p.  399.  
Purification  of  Carbon  Bisulphide. — P.  Palmieri  recommends 
removing  the  stratum  of  water,  with  which  commercial  carbon  bisulphide 
is  usually  covered,  and  then  adding  2  or  3  per  cent,  of  exsiccated  sulphate 
of  copper;  the  mixture  is  agitated,  and  when  the  copper  salt  has 
become  black  and  subsided,  and  the  odor  of  hydrogen  sulphide  ha& 
disappeared,  the  liquid  is  decanted  or  filtered,  or  better  still,  it  may  be 
rectified  in  the  presence  of  a  little  exsiccated  copper  sulphate.  By  this 
treatment  the  disagreeable  odor  is  completely  removed,  and  in  order  to 
preserve  the  purity  of  the  liquid,  it  is  advisable  to  keep  in  it  a  small 
quantity  of  the  copper-salt.  The  salt  after  having  been  used  as  above 
stated,  may  be  ignited,  treated  with  sulphuric  acid,  and  again  ignited, 
when  it  is  again  suitable  for  the  above  purpose. — Zeitschr.  Anal. Chem. ^ 
xxi,  254. 
