ON  THE  PURITY  OF  ALCOHOL. 
417 
When  the  action  of  the  sodium  was  assisted  by  heat,  until  it 
was  no  longer  attacked,  a  liquid  possessing  the  odor  and  density 
of  caprylene,  and  boiling  like  it  at  255°  F.,  was  obtained.  Its 
composition  is  C16  H19  =  4  vols.    Analysis  gave : — 
Found.  Calculated. 
Carbon  85-59       16  85-71 
Hydrogen  14-40       16  11-29 
The  density  of  its  vapor  was  3-80  =  4  vols.  Calculation 
requires  3-86  London  Chem.  Cfaz,  from  Oomptes  Bendus,  May 
22d,  1854,  p.  935. 
ON  THE  PURITY  OF  ALCOHOL. 
By  Edward  N.  Kent. 
In  a  recent  investigation  which  required  the  use  of  alcohol 
perfectly  free  from  fusel  oil,  I  was  led  to  suspect  that  nitrate  of 
silver  could  not  be  depended  upon  as  a  test  for  this  substance, 
and  upon  mixing  pure  fusel  oil  with  pure  alcohol,  verified  my 
suspicion.  Nitrate  of  silver  is  not  reduced  by  fusel  oil,  even  by 
boiling,  but  it  is  true  that  alcohol  frequently  contains  other 
organic  substances  by  which  nitrate  of  silver  is  reduced  when 
mixed  with  it  and  exposed  to  heat  and  light.  Most  of  these  sub- 
stances can  be  removed  by  simple  distillation,  but  fusel  oil  can- 
not be  removed  in  this  manner,  and  consequently  this  substance 
constitutes  the  most  usual  and  injurious  impurity  in  all  commer- 
cial alcohol.  To  detect  its  presence  I  find  that  pure  sulphuric 
acid  is  the  best  and  most  convenient  test,  and  as  I  am  not  aware 
that  this  acid  has  before  been  used  for  this  purpose,  I  will  pro- 
ceed to  describe  the  method  of  using  it  as  a  test  for  fusel  oil. 
It  is  well  known  that  when  concentrated  sulphuric  acid  is  mixed 
with  fusel  oil  that  a  dark  purple  mixture  is  produced,  with  the 
formation  of  sulpho-amylic  acid.  This  fact  forms  the  basis  of  a 
new  test  for  fusel  oil.  When  pure  sulphuric  acid  is  added  slowly 
to  pure  alcohol,  the  mixture  remains  perfectly  colorless ;  but  if 
it  be  added  to  alcohol  containing  the  least  trace  of  fusel  oil,  the 
mixture  becomes  colored  in  proportion  to  the  amount  of  impurity. 
The  most  convenient  method  of  applying  this  test  is  to  fill  a 
small  test  tube  to  one-half  its  capacity  with  the  spirit  to  be 
tested ;  the  tube  is  then  to  be  filled  with  pure  concentrated  sul- 
27 
