ON  THE  DETECTION  OF  METHYLIC  ALCOHOL,  ETC.  59 
The  solution  I  use,  and  which,  in  what  follows,  will  be  spoken 
of  as  "the  test,"  is  made  by  dissolving  1  grain  of  crystallized 
permanganate  of  potash  in  1  fluidounce  of  distilled  water. 
Spirit  of  Wine. — 1.  If  10  minims  of  the  test  be  added  to  4 
fluid  drachms  of  the  purest  rectified  spirit  in  a  test  tube,  the 
mixture  will  be  found  to  retain  the  bright  pinkish  color  so  cha- 
racteristic of  permanganate  of  potash,  for  at  least  ten  minutes, 
when  it  gradually  fades.  As  regards  color,  this  may  be  taken 
as  a  standard  for  comparison. 
2.  Add  10  minims  of  the  test  to  4  fluid  drachms  of  the  same 
spirit,  previously  mixed  with  two  per  cent,  of  wood  naphtha. 
The  difference  between  this  and  the  pure  spirit  is  at  once  ap- 
parent. The  liquid  no  longer  retains  its  characteristic  color, 
but  almost  instantly  changes  to  a  dull  pale-brown  tint. 
3.  Add  10  minims  of  the  test  to  4  fluid  drachms  of  pure 
spirit,  previously  mixed  with  ten  per  cent,  of  wood  naphtha,  as 
in  methylated  spirit.  Here  the  change  in  the  color  of  the  test 
is  even  more  striking,  the  liquid  at  once  assuming  the  brown 
tint,  as  in  experiment  2,  only  in  a  greater  degree. 
So  great  is  the  delicacy  of  the  test,  that  1  part  of  wood  spirit 
in  300  of  rectified  spirit  of  wine  may  be  readily  detected  by  its 
aid  ;  but  1  imagine  it  will  be  most  valued  in  the  next  applica- 
tion I  shall  speak  of, — viz. :  to  sulphuric  ether,  as  no  ready 
method  has  been  published  for  distinguishing  the  pure  from  that 
containing  ten  per  cent,  of  oxide  of  methyl,  prepared  from  me- 
thylated spirit.  The  pure  ether,  used  in  the  following  experi- 
ment, was  Howard's  make. 
Sulphuric  Ether. — Take  two  clean,  dry  test  tubes,  put  4  fluid 
drachms  of  pure  ether  into  one,  and  the  same  quantity  of  me- 
thylated ether  in  the  other ;  place  side  by  side,  and  add  to  each 
10  minims  of  the  test,  mixed  immediately  before  use  with  50 
minims  of  pure  rectified  spirit,  to  render  it  more  readily  misci- 
ble  with  the  ether.  The  pure  ether  will  retain  the  pinkish  hue, 
imparted  to  it  by  the  test,  for  a  considerable  time ;  whilst  that 
made  from  methylated  spirit  changes  to  a  pale  brown  in  a 
minute  or  so.  By  adding  successive  portions  of  the  test,  the 
same  effects  will  be  observed,  as  the  oxide  of  methyl  appears 
