MANUFACTURE  OF  ALUMINIUM. 
457 
ine  mixed  with  a  little  extractive  matter  perfectly  free  from 
strychnine  ;  the  other  yielded  extractive  matter  alone.  The 
test  of  sulphuric  acid  and  nitrate  of  potash  was  then  applied  ; 
the  brownish  red  color  was  produced  in  the  first  case,  in  the 
second  there  was  no  change.  To  ascertain  the  readiness  with 
which  minute  quantities  of  picrotoxine  can  be  detected  2q  of  a 
gramme  of  it  was  dissolved  in  a  pint  of  ale  ;  this  was  acidulated 
and  treated  as  above ;  the  ethereal  extract  furnished  ample 
proof  of  the  poison  when  tested. 
In  another  experiment  the  stomach  of  a  cat  which  had  been 
poisoned  was  emptied  of  its  contents  so  that  only  the  picrotox- 
ine absorbed  by  the  coats  of  the  stomach  might  be  extracted.  It 
was  treated  with  alcohol  and  the  solution  evaporated  to  dryness. 
Acidulated  water  being  poured  on  the  residue,  the  picrotoxine 
and  a  little  organic  matter  were  dissolved  ;  being  now  treated 
with  ether  and  the  solution  evaporated,  small  crystals  of  picro- 
toxine were  obtained,  which,  when  tested,  produced  the  char- 
acteristic red  color,  A  portion  of  animal  matter  free  from 
poison  treated  in  the  same  way  gave  no  discoloration. 
In  examining  a  liquid  for  picrotoxine  it  should  first  be  ren- 
dered acid,  then  shaken  with  ether  ;  the  residue  left  on  evapo- 
ration of  the  ether  examined  with  the  microscope  for  small  pris- 
matic crystals  ;  if  a  few  drops  of  sulphuric  acid  diluted  with  its 
volume  of  water  are  added  in  the  cold,  and  there  are  alkaloids 
present,  they  will  dissolve,  only  so  much  picrotoxine  passing 
into  solution  as  is  due  to  the  water  present,  about  one  part 
for  one  hundred  and  fifty  of  water.  A  few  drops  of  an  alka- 
line fluid  will  dissolve  the  crystals,  and  on  applying  heat  the 
fluid  will  become  first  yellow  and  when  more  strongly  heated 
will  become  brick-red.  A  small  portion  ground  in  a  watch- 
glass  with  nitrate  of  potassa  and  sulphuric  acid  gives  a  solution 
which  when  rendered  alkaline  by  potash  or  soda  becomes  a 
bright-red  Amer.  Journ.  Sci.  and  Art,  July,  1862. 
MANUFACTURE  OF  ALUMINIUM. 
We  have  repeatedly  mentioned  to  our  readers  the  progress  of 
the  manufacture  of  Aluminium  since  St.  Claire  Deville  dis- 
