Am  Jour.  Pharm.  I 
March,  1895.  / 
Manufacture  of  Acetone. 
147 
(2)  Next  this  stationary  tube  was  filled  with  coarsely-granulated  pumice- 
stone,  freed  from  large  pieces  and  from  dust,  and  so  tightly  packed  as  to  have 
spring  enough  to  keep  the  tube  full  when  expanded  by  heating.  Into  this,  in 
3*5  hours,  189  Gm.  of  absolute  acid,  in  vapor,  was  pass  <1.  and  yielded  in  the 
first,  hot  flask  103  Cc.  of  54  p.  c.  acid  =  55*62  Gm.  a  solute  acid.  In  the 
second,  ice-bath  flask  138  Cc.  of  38*4  p.  c.  acid  =  52*97  Gm.  of  absolute  acid, 
making  108*6  Gm.  out  of  189  Gm.  distilled  over  unchanged,  and  80  4  Gm.  de- 
composed. The  contents  of  this  second  flask  were  about  14  5  p.  c.  acetone. 
The  stream  of  inflammable  gases  was  estimated  as  being  not  less,  but  rather 
greater  than  with  the  empty  tube. 
(3)  Next,  took  the  pumice  from  the  tube,  divided  it  into  two  parts,  and, 
rejecting  one-half,  intimately  mixed  with  the  other  half  500  Gm.  of  dry  precip- 
itated barium  carbonate.  Charged  the  tube  with  this  mixture,  having  a  little 
unmixed  pumice  at  both  ends.  Barium  carbonate  was  selected  to  multiply 
surface,  as  being  a  rather  heavy  powder  that  would  not  shrink  nor  fuse,  nor  be 
likely  to  decompose. 
About  450  Cc.  of  60  p.  c.  acid  =  270  Gm.  of  absolute  acid  was  passed,  in 
vapor,  in  3*5  hours,  into  this  mixture,  heated  as  before.  The  distillate  in  the 
first  hot  flask  was  8e  Cc.  of  acid  water  of  only  i*6  p.  c.  =  1*3  Gm.  absolute 
acid.  In  the  second  ice-bath  flask  was  227  Cc.  s.  g.,  about  0*955,  containing  1*2 
p.  c.  acid  =  2.7  Gm.  absolute  acid.  Of  the  270  Gm.  passed  in,  4  Gm.  only  dis- 
tilled over  unchanged,  while  266  Gm.  was  decomposed.  The  227  Cc.  of  dis- 
tillate in  the  second  flask  contained  about  23*3  p.  c.  of  acetone.  This  proportion 
gives  about  20  p.c.  of  acetone  from  the  266  Gm.  of  absolute  acid  used.  The 
stream  of  inflammable  gases  was  very  much  greater  than  in  the  other  experi- 
ments, burning  with  an  almost  continuous  large  flame. 
The  desired  splitting  of  acetic  acid  to  yield  acetone  requires  2  molecules  of 
the  acid  to  yield  1  molecule  of  acetone,  the  residuary  products  being  1  mole- 
cule each  of  carbon  dioxide  and  water.  That  is,  120  Gm.  of  absolute  acetic  acid 
should  give 
58  Gm.  of  acetone, 
44    "     "  carbon  dioxide, 
18    "     "  water,  or 
by  percentage  the  acid  should  give 
48*33  p.  c.  acetone, 
36*67    "   carbon  dioxide. 
15*00    "  water. 
When  marsh  gas  or  methane  iCH4)  and  carbon  monoxide  (CO)  are  formed 
it  is  probably  largely,  if  not  entirely,  through  a  secondary  decomposition  of 
the  acetone  by  a  higher  heat  than  that  which  gives  the  primary  decomposition 
into  acetone,  carbon  dioxide  and  water,  and  when  acetone  and  methane  are 
produced  together,  it  is  rational  to  suppose  that  inequalities  of  heating  are  the 
cause.  That  is,  if  acetone  be  produced  it  indicates  that  the  exact  conditions 
required  are  present  at  that  time  and  place.  Then  it  follows  that  if  these  exact 
conditions  be  extended  throughout  the  whole  time  and  place  of  reaction,  the 
acetone  splitting  of  the. acid  only  can  occur,  and  no  methane  or  other  products 
of  other  reactions  can  be  produced.  The  conditions  for  producing  these  differ- 
ent reactions  are  doubtless  different  degrees  of  heating,  and  uniformity  of  reac- 
