ON  FORMIC  ACID. 
219 
ture,  and  allowed  to  stand  for  a  day  or  two,  and  then  distilled. 
The  distillation  was  continued  until  the  residue  in  the  retort  was 
almost  dry.  Towards  the  end  of  the  distillation,  crystals  of 
methyloxalic  ether  began  to  form  in  the  neck  of  the  retort.  The 
distillate,  which  amounted  to  about  ten  fluid  ounces,  being  exposed 
to  the  air  for  a  day  or  two  to  evaporate  spontaneously,  became 
an  almost  solid  mass  of  crystals  of  the  ether. 
These  crystals  were  of  a  beautiful  white  color,  dissolved  in 
water,  alcohol  and  ether,  were  decomposed  by  boiling  with  watert 
and  the  solution  by  evaporation  yielded  fine  crystals  of  oxalic 
acid.  By  passing  dry  ammoniacal  gas  over  a  portion  of  the 
ether,  and  then  dissolving  the  product  in  alcohol,  and  evapo- 
rating, a  beautifully  crystalline  compound  is  obtained,  to  which 
the  name  of  methyloxamic  ether  has  been  given.  The  remainder 
of  the  crystals,  as  first  obtained,  were  pressed  between  the  folds 
of  filtering  paper,  and  by  exposition  over  sulphuric  acid  were 
deprived  of  adherent  volatile  products,  (this  treatment  changed 
their  color  to  a  light  brown,)  and  then  distilled  with  water;  the 
distillate  was  then  distilled  three  successive  times  with  lime,  and 
afforded  methylic  alcohol  almost  entirely  free  from  water.  It  was 
a  light  colorless  liquid,  having  a  faint  odor  of  acetic  ether,  burned 
in  the  air  with  a  faint  blue  flame,  and  resembled  in  its  solvent 
powers  those  of  ordinary  vinic  alcohol.  The  formula  C2H402  is 
given  for  it. 
Methylic  alcohol  is  oxidized  rapidly  when  dropped  on  platina 
black,  (especially  if  the  temperature  be  elevated,  )  at  the  expense 
of  the  oxygen  of  the  air,  and  formic  acid  is  formed.  Methylic 
alcohol,  C2H402,  by  gaining  04  from  the  air,  becomes  C2H406 
and  by  giving  off  3  eq.  of  water,  becomes  C2H03-f-HO,  or 
formic  acid.  This  is  precisely  the  same  reaction  that  takes  place 
when  alcohol  is  converted  into  acetic  acid.  Formic  acid  is  also 
produced  when  many  organic  substances  are  subjected  to  oxidi- 
zing agents. 
A  good  formula  for  making  this  acid,  is  that  given  in  the 
Journal,  vol.  xxviii.  One  pound  of  oxalic  acid  was  mixed  with 
one  pound  of  glycerin  and  three  ounces  of  water,  and  the  whole 
kept  at  a  temperature  of  212°  F.  for  15  hours,  (the  temperature 
should  not  be  allowed  to  get  much  above  this  point,  as  the  acid 
itself  might  be  decomposed,)  or  until  the  oxalic  acid  was  entirely 
