60 
OLEUM  ^THEREUM. 
this  experiment  shows  that  the  separation  is  less  as  the  proportion 
of  ether  added  increases,  quite  independent  of  the  amount  of 
alcohol  with  which  the  ether  may  be  previously  mixed.  This 
experiment  proves  conclusively  that  the  opinion  hitherto  enter- 
tained and  published  by  the  writer  that  alcohol  was  a  preserva- 
tive agent  was  altogether  erroneous.  This  error  had,  however, 
been  detected  in  practice  before  the  direct  experiment  was  made. 
It  is  useless  to  take  up  the  time  of  the  Association  with  a 
detail  of  the  experiments  made  to  determine  the  above  points, 
and  they  were  for  the  most  part  mere  admixtures  of  the  oil  with 
different  menstrua  in  different  proportions,  and  were  all  based 
upon  the  well  known  fact  that  the  oil  when  made  at  once  into  the 
compound  spirit  of  ether  keeps  indefinitely.  It  is,  therefore, 
judged  sufficient  to  exhibit  to  the  Association  the  various  speci- 
mens which  lead  to  these  statements,  together  with  specimens  of 
the  undiluted  oil  made  at  various  periods  during  the  past  eight 
years. 
A  portion  of  the  space  saved  by  a.voiding  unnecessary  detail 
of  experiments  may,  however,  be  usefully  occupied  with  some 
statistics  of  the  process  and  results  in  preparing  the  officinal 
ethereal  oil. 
Since  the  last  meeting  of  the  Association  the  writer  has  used 
in  preparing  ethereal  oil  1664  lbs.  of  sulphuric  acid  s.  g.  1-845, 
and  686  lbs.  or  lOOi  gallons  of  alcohol  s.  g.  -835.  These 
materials  yielded  87  fluid  ounces,  equal  to  88'4  troy  ounces,  or 
97  avoirdupois  ounces,  of  the  finished  oil.  The  distillation  occu- 
pied twenty-one  days,  one  charge  being  distilled  each  day.  It 
was  performed  in  seven-gallon  French  white  glass  retorts,  and  the 
charges  required  from  eleven  to  seventeen  hours  for  workings 
Three  retorts  were  lost  in  the  process  ;  one  breaking  in  the  sand 
pot, — the  other  two  being  broken  in  the  difficult  and  troublesome 
cleaning  that  is  necessary  after  each  charge,  to  free  them  from 
the  adhering  carbonaceous  matter  and  thiomelanic  acid.  These  re- 
torts cost  seven  dollars  each,  but  prove  to  be  more  economical 
than  those  made  in  this  country,  from  being  less  frequently  lost  in 
the  sand  bath.  The  charge  lost  in  the  sand  bath  took  fire,  of  course, 
and  was  totally  lost.  Two  more  of  the  twenty-one  were  partially 
lost  by  frothing  over  the  contents  of  the  retort.  The  process 
required  the  almost  undivided  attention  of  one  person,  and  a 
