AmMarch)T8b96!'m-}      Acetone  and  Acetone-Chloroform.  147 
year  later  by  the  first-mentioned  company,  which  made  the  acetone 
for  both." 
From  these  references  it  will  be  seen  that  the  reactions  involved 
in  the  production  of  acetone,  and  the  constitution,  character,  prop- 
erties and  reactions  of  acetone,  had  been  long  and  well  known  prior 
to  1848,  and  that  it  had  been  made  and  utilized  on  a  large  scale 
prior  to  1882  ;  and  further,  that  it  had  been  produced  both  by  the 
dry  distillation  of  acetates  and  by  the  wet  distillation  of  acetic  acid, 
as  a  matter  of  open  knowledge  and  practice. 
This  condition  of  the  scientific  knowledge  of  an  important  chem- 
ical substance  throughout  France  and  Germany — and  throughout 
the  scientific  world — makes  it  very  certain  that  the  chemical  indus- 
tries, which  depend  upon  such  knowledge  for  their  origin  and  pro- 
gress in  general,  but  do  not  publish  their  processes — availed  them- 
selves of  this  knowledge  and  of  this  chemical  agent. 
In  June,  of  1886,  application  was  filed  in  the  U.  S.  Patent  Office, 
and  two  years  later,  in  July,  1888,  Letters-Patent,  No.  385, 777, were 
issued  to  Gustav  Rumpf,  for  the  invention  of  "  a  new  and  useful 
Improvement  in  the  Manufacture  of  Acetone,"  and  from  the  speci- 
fications and  claims  of  this  patent  the  following  extracts  are  made  : 
"  In  making  acetone  by  dry  distillation  of  acetates — as  acetate 
of  lime — it  has,  before  my  invention,  been  thought  possible  to 
obtain  only  less  than  half  the  acetone. 
"  Dr.  Hermann  Hager,  in  his  Handbuch  der  Pharmaceutischen 
Praxis,  published  in  Berlin  in  1882,  states,  under  the  head  of 
'Acetone,'  '  that  it  is  possible  to  obtain  an  average  yield  from  chem- 
ically pure  acetate  of  lime,  only  15  per  cent,  of  acetone,  while  the 
theoretical  yield  from  chemically  pure  acetate  of  lime  is  34  per 
cent. 
"  I  have  discovered  that  if  the  acetates  are  subjected  for  distilla- 
tion to  a  low  heat  and  approximately  uniform  temperature,  and  the 
process  extended  over  several  hours,  the  yield  of  acetone  will  be 
greatly  increased,  and  will  approach  very  nearly  the  theoretical 
yield  of  any  particular  acetate,  which,  in  the  case  of  good  gray  or 
commercial  acetate  of  lime,  is  about  27  per  cent.  I  have  also  dis- 
covered that  in  the  process  of  subjecting  acetates  in  a  closed  vessel 
to  heat  applied  externally  to  the  vessel  for  distilling  acetone  from 
the  acetates,  the  desired  slowness  of  distillation  and  uniformity  of 
temperature  may  be  secured  by  stirring  the  acetates  so  that  all  por- 
