130 
Purification  of  Methylic  Alcohol. 
/Am.  Jour.  Pharm. 
I     March,  1888. 
potassium  oxalate  and  methyl  hydrate.  Pure  methylic  alcohol  possibly 
could  be  used  in  pharmacy  as  a  solvent,  and,  in  some  instances, 
take  the  place  of  the  more  expensive  ethyl  hydrate;  but  the  above 
process,  owing  to  the  large  amount  of  potassium  or  sodium  hydrate 
required  to  decompose  the  oxalate,  is  quite  expensive. 
After  having  tried  all  the  different  processes  recommended  in  the 
books,  I  came  to  the  conclusion  that  neither  of  these  yielded  a  sufficiently 
cheap  product;  and  lime  suggesting  itself  as  a  cheap  reagent  for  the  pur- 
pose, I  began  a  series  of  experiments  with  an  alcohol  that  boiled  at  68°  C. 
and  had  a  specific  gravity  of  .826.  By  treating  with  oxalic  acid  methyl 
oxalate  was  formed.  The  still  being  ready  a  quantity  of  dry  carbo- 
nate of  potassium  was  added,  and  then  the  lime  in  small  lumps, 
quickly  connecting  with  the  condenser.  In  a  few  minutes  the  reaction 
goes  on  by  itself,  or  sometimes  requires  the  aid  of  a  little  heat ;  dis- 
tillation is  stopped  when  but  about  one-sixth  of  the  quantity  is  over. 
As  it  first  comes  over  methyl  alcohol  is  odorless,  and  keeps  so  for 
quite  awhile,  but  on  exposure  to  the  atmosphere  it  soon  acquires  that 
well-known  peculiar  odor,  but  not  as  strong  as  the  commercial  alcohol, 
and  not  empyreumatic.  Then,  after  treating  with  carbonate  of  potas- 
sium, distilling  and  adding  a  few  grains  of  permanganate  of  potassium 
to  the  distillate  the  odor  is  destroyed,  but  comes  back  again,  though 
more  pleasant  and  less  disagreeable.  In  this  condition,  and  by  a  little 
more  purification,  I  think  it  can  be  used  in  some  preparations. 
The  advantage  of  lime  is  its  cheapness,  and  that  by  hydration  it 
produces  enough  heat  to  start  the  reaction,  and  to  vaporize  the  alcohol 
at  the  same  time. 
Methyl  oxalate  cannot  be  decomposed  by  heat  when  in  a  solution 
of  water ;  but  on  heating  in  the  air  it  is  decomposed. 
The  alcohol  obtained  by  that  process  had  the  specific  gravity  '889 
and  contained  still  some  water,^  which,  I  think,  can  be  extracted  by 
careful  distilling  from  K2CO3.    Its  boiling  point  is  66°  C. 
Antiseptic  Petrolatum.— Brondel's  formula,  as  printed  on  page  103 
of  this  volume,  contains  an  error  in  the  quantity  of  corrosive  sublimate. 
The  correct  formula  is  as  follows:  Corrosive  sublimate,  0"10;  oil  of  eucalyp- 
tus, 10 ;  soft  paraffin,  100  parts. 
^  According  to  the  table  of  Duclaux  the  specific  gravity  indicates  about  70  per 
cent,  by  weight  of  methyl  alcohol. — Editor. 
