39^ 
Comparison  of  Acetic  Ethers. 
Am.  Jour.  Piiarm. 
Aug..  1891. 
extent,  and  a  large  bulk  of  it  goes  into  the  manufacture  of  artificial 
fruit  essences.  It  has  also  of  late  years  been  used  considerably  for 
giving  the  "  vinegar  flavor  "  to  artificial  vinegar,  made  by  diluting  the 
commercial  glacial  acetic  acid.  One  fluid  ounce  of  acetic  ether  to  a 
barrel  gives  a  fragrant  fruity  odor  to  the  compound,  which  is  very 
desirable,  and  in  which  many  of  the  natural  vinegars  are  lacking. 
It  was  in  this  connection  that  the  samples  for  comparison  were 
obtained,  and  as  a  basis  a  sample  of  acetic  ether  was  made  as  free 
from  alcohol,  water  and  impurities  as  it  was  possible  to  make  it. 
Absolute  Acetic  Ether. — Dried  acetate  of  sodium  was  decomposed 
with  concentrated  sulphuric  acid  and  alcohol,  and  the  acetic  ether 
distilled  off  by  the  aid  of  a  water  bath.  This  distillate  was  then 
thoroughly  washed  with  water  containing  about  25  per  cent,  of  cal- 
cium chloride  in  solution  (the  ether  being  less  soluble  in  this  mixture 
than  in  water  alone),  and  the  washing  repeated  successively  five 
times  to  remove  the  alcohol  present  ;  then  digested  with  fused 
chloride  of  calcium  to  free  it  from  water,  and  finally  distilled  over 
anhydrous  acetate  of  sodium  on  a  water  bath. 
The  separation  of  the  last  trace  of  alcohol  by  the  above  process 
is  very  tedious  and  wasteful ;  in  acetic  ether  made  by  the  following 
method,  this  disadvantage  is  obviated:  150  parts  of  dried  sodium 
sulphethylate  were  decomposed  by  85  parts  of  dried  acetate  of 
sodium  and  about  20  parts  of  sulphuric  acid,  and  the  acetic  ether 
which  was  produced  by  the  reaction,  was  distilled  off  from  the  sul- 
phate of  sodium,  and  condensed  in  a  receiver  surrounded  by  ice. 
This  ether  had  an  acid  reaction  from  the  presence  of  free  acetic  acid, 
but  was  entirely  free  from  any  contamination  with  alcohol.  To 
free  it  from  acid,  it  was  shaken  with  a  few  crystals  of  bicar- 
bonate of  potassium  until  all  acidity  had  disappeared.  It  was 
then  washed  with  a  3  per  cent,  solution  of  permanganate  of  potas- 
sium to  free  it  from  any  oxidizable  compounds  which  may  have 
been  present;  then  digested  with  half  its  weight  of  fused  chloride 
of  calcium,  decanted  and  distilled,  by  the  aid  of  a  waterbath  over 
anhydrous  acetate  of  sodium. 
This  gave  as  a  result  a  clear,  colorless,  refractive,  volatile  liquid, 
with  a  burning  taste.  The  odor  on  fresh  distillation  was  very  weak, 
but  on  standing  for  a  day  was  more  decidedly  developed.  This 
ether  had  a  specific  gravity  of  -8893  at  15-5°  C,  and  a  boiling  point 
of  720  C.    It  had  a  neutral  reaction  and  dissolved  in  1 1  parts  of 
