FUSEL  OIL  FROM  INDIAN  CORN  AND  RYE. 
419 
sulphate  of  potassa  separated  on  concentration,  was  avoided  partly 
by  removing  the  crystals,  and  partly  by  using  a  ring  gas  burner 
made  from  a  tube,  and  by  which  means  the  upper  portion  of  the 
retort  could  be  heated,  while  the  bottom  was  kept  in  sand.  A 
small  portion  of  dark  matter  was  left  with  the  residue  and  crystals 
in  the  retort.  This  was  tested  for  fatty  acids  (after  neutralizing 
the  free  acid  and  separating  the  sulphate  of  potassa  by  alcohol, 
by  nitrate  of  silver;  a  very  small  quantity  of  whitish  brown  pre- 
cipitate was  obtained,  which  did  not  crystallize  from  boiling 
water. 
The  distillate  containing  the  volatile  fatty  acids,  consisted  of  an 
acid  aqueous  fluid,  upon  which  floated  drops  of  dark  colored  acid 
oil,  of  a  peculiar  rancid  smell.  A  small  portion  of  the  aqueous 
fluid  was  neutralized  by  carbonate  of  soda,  was  added  to  the  rest 
and  distilled  ;  nitrate  of  silver  added  to  the  solution  of  the  residue 
in  the  retort  caused  a  white  precipitate,  which  immediately  black- 
ened on  heating  the  test  tube,  indicating  the  presence  of  formic 
acid.  The  whole  of  the  distillate  was  neutralized  by  carbonate 
of  soda,  and  evaporated  in  vacuo ;  it  crystallized  in  needles  like 
acetate  of  soda.  As  the  quantity  was  too  small  for  an  analysis,  it 
was  heated  with  sulphuric  acid  and  alcohol  in  a  test  tube  ;  the 
smell  of  acetic  ether  was  distinct. 
The  fatty  acids  arising  from  decomposing  the  different  potassa 
solutions  were  together  in  such  small  quantities,  (although  a  gal- 
lon and  a  half  of  fusel  oil  was  employed.)  that  they  were  united. 
About  Jth  was  neutralized  by  NaOC02,  added  to  the  whole,  and 
distilled.  Another  portion  of  the  distillate  resulting  from  this 
experiment,  was  treated  in  the  same  manner,  and  finally  the 
whole.  The  soda  salts  thus  resulting,  I  call  1,  2,  and  3 ;  they 
were  not  in  large  quantity.  A  drop  of  the  solution  of  each,  eva- 
porated upon  a  glass  plate,  was  examined  with  the  microscope. 
No.  1  appeared  in  fibrous  crystals  converging  towards  the  cen- 
tre of  the  drop. 
No.  2  appeared  to  consist  of  two  different  kinds  of  crystals, 
especially  as  seen  by  polarized  light ;  one  kind  in  one  position 
of  the  plane  of  blue  plumose  crystals ;  and  the  other  of  white 
stellated  prisms. 
No.  3,  evaporated  at  ordinary  temperature,  appeared  in  feathery 
stellated  crystals. 
