44 
PREPARATION  OF  PURE  METHYL-ALCOHOL. 
of  duty  into  England  ;)  they,  in  the  latter  countries,  manufac- 
tured at  a  profit,  and  we  at  a  loss ;  and  the  result  was,  after 
repeated  attempts,  the  London  makers  were  compelled  to  give 
way  to  their  Scotch  friends,  though  not  in  quality  but  in  price  
Annals  of  Pharmacy,  Jan.  1852. 
PREPARATION  OF  PURR  METHYL- ALCOHOL. 
By  F.  Wohler. 
It  is  known  how  very  difficult  it  is  to  obtain  pure  methyl-alco- 
hol from  crude  wood-spirit.  The  following  method,  founded  upon 
the  crystallizability  of  the  oxalic  methyl-ether,  appears  to  be  the 
most  convenient  for  its  preparation,  at  least  in  small  quantities. 
A  quantity  of  crude  wood-spirit  is  gradually  mixed,  so  as  to 
prevent  over-heating,  with  an  equal  weight  of  concentrated  sul- 
phuric acid.  The  brown  mixture  is  then  submitted  to  distillation, 
in  a  tubulated  retort,  with  two  parts  by  weight  of  superoxalate 
of  potash.  It  might  be  advisable  to  let  the  mass  stand  for  twenty- 
four  hours  before  distilling.  A  volatile  and  combustible  fluid 
first  passes  over  and  is  followed  by  oxalic  ether,  which  begins  to 
condense  in  the  neck  of  the  retort.  The  receiver  is  then  removed, 
and  the  distillation  continued,  as  long  as  any  oxalic  ether  passes 
over,  the  disengagement  of  which  is  assisted  by  gently  heating 
the  tube.  It  is  then  pressed  strongly  between  folds  of  blotting- 
paper  and  freed  from  any  small  quantity  of  adherent  volatile 
products,  either  by  placing  it  over  sulphuric  acid  or  by  a  protracted 
fusion.  In  this  manner  it  may  be  immediately  obtained  quite 
colorless.  The  combustible  fluid  which  first  passes  over  contains 
some  diluted  oxalic  ether,  which  may  be  crystallized  by  evapora- 
tion at  a  moderate  heat.  The  rough  wood-spirit  employed  by 
me  in  the  experiment  was  so  impure  that,  when  mixed  with  water, 
it  became  milky,  and  it  produced  in  this  manner  more  than  one- 
quarter  of  its  weight  of  pure  oxalic  ether. 
In  order  to  prepare  methyl-alcohol  from  oxalic  ether  it  will  be 
best  to  distil  it  with  water  only,  which  process,  it  is  known,  trans- 
forms it  into  oxalic  acid  and  methyl-alcohol.  In  distilling  it  with 
dry  hydrate  of  lime  it  will  not  be  decomposed,  and  in  distilling 
it  with  a  concentrated  lye  of  potash  its  decomposition  is  only  par- 
tial, because  then  a  methyl-potash  salt  is  formed,  which  is  most 
