Am.  Jour.  Pharm. 
3Iarch,  189fi. 
Acetone  and  Acetone-Chloroform. 
149 
Materia  Medica,  Pharmacy,  Therapeutics  and  Collateral  Information, 
Vol.  IV,  No.  3,  p.  1653.  ' 
The  writer  makes  acetone  by  the  destructive  distillation  of  the 
watery  vapor  of  acetic  acid  in  a  rotary  still,  in  the  presence  of  ba- 
rium carbonate,  or  pumice-stone,  or  bone-charcoal,  barium  carbonate 
being  preferred  because,  being  a  very  heavy  powder,  a  larger  charge 
of  smaller  volume  can  be  used. 
The  patentees  claim  only  acetates  as  their  material,  but  claim  in- 
fringement by  the  use  of  acetic  acid,  because  acetic  acid  is  made 
from  acetates,  and  acetates  are  made  from  acetic  acid  ;  and,  secondly, 
claim  infringement  on  the  ground  that  acetate  of  barium  is  first 
formed,  and  then  decomposed  in  the  rotary  still,  and,  therefore,  the 
process  is  really  not  a  destructive  distillation  of  acetic  acid,  but  of 
barium  acetate — one  of  the  class  of  acetates  claimed  as  secured  to 
them  by  their. patent,  although  in  use  for  this  purpose  for  so  many 
years.  That  is,  it  is  claimed  that  an  acetate  of  barium  is  formed 
under  conditions  of  temperature  in  which  an  acetate  of  barium  Can- 
not exist.  Barium  acetate  decomposes  at  about  4000  to  405  °  C.  by 
an  ordinary  pyrometer.  Acetic  acid  is  best  decomposed  at  about 
5000  to  525 0  C.  by  the  same  pyrometer,  and  yet  it  is  claimed  that, 
at  5000  C,  barium  acetate  forms  momentarily  and  then  is  instantly 
decomposed.  That  is,  it  is  formed  in  an  atmosphere  in  which  it 
cannot  exist  for  an  instant,  and  in  which  acetic  acid  cannot  exist.9 
9  Upon  this  point  the  patentees  were  very  decided  in  the  statement,  based 
not  only  on  their  own  experience,  but  also  on  the  experience  of  their  German 
correspondents,  that,  if  the  barium  carbonate  was  replaced  by  pumice-stone,  the 
amount  of  acetone  obtained  would  be  too  small  to  have  any  commercial  im- 
portance. This  result  had  been  confirmed  to  them  by  so  many  trials  that,  at 
their  suggestion,  and  in  order  to  satisfy  them  that  their  results  were  not  trust- 
worthy, the  following  experiments  were  made  after  the  above  paper  was  writ- 
ten, but  before  it  was  published. 
The  large  rotary  still  was  emptied  and  cleaned  out  by  sweeping,  scraping 
and  finally  by  sponging  with  water  until  it  was  quite  free  from  any  appreciable 
quantity  of  barium  salt.  It  was  then  closed  and  run  empty  with  a  continuous 
feed  of  acetic  acid  for  periods  of  three  hours  each,  at  the  following  tempera- 
tures, the  rate  of  feeding  and  the  assaying  for  acid  and  acetone  being  approx- 
imate only,  and  only  trustworthy  by  averaging: 
At  3000  C.  22-3  pounds  of  absolute  acid  was  run  in,  and 
I9-5 
received  without  any  acetone  or 
any  evidence  of  decomposition  of  the  acid,  the  2 '8  pounds 
of  acid  not  accounted  for  being  the  normal  charge  of  the 
apparatus. 
