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RESEARCHES  ON  THE  ETHERS. 
This  production  is  effected  by  heating  the  acid  and  ether,  en 
closed  in  very  strong  tubes,  to  about  680°-752°  F. 
The  author  has  procured  benzoic  ether  in  this  manner  from 
ether  and  benzoic  acid.  It  possessed  the  odor  and  specific  pro- 
perties of  benzoic  ether,  boiled  at  416°  F.,  and  ga  ve  on  analysis — 
Formula. 
Carbon  ....  72'2  720 
Hydrogen    ...      67  6*7 
Treated  with  potash  and  water,  it  reproduces  the  benzoic  acid; 
and  in  place  of  the  ether,  a  volatile  inflammable  liquid,  soluble  in 
water,  which,  when  touched  with  a  drop  of  a  mixture  of  sulphuric 
and  butyric  acids,  evolves  the  odor  of  butyric  ether.  These  cha- 
racters belong  to  alcohol. 
The  ether  employed  in  the  preceding  experiment  had  been  shaken 
five  times  with  its  volume  of  water,  so  as  gradually  to  dissolve  the 
half ;  it  was  then  dried  upon  chloride  of  calcium,  and  rectified. 
After  nine  hours'  contact  with  the  benzoic  acid  at  680°  F.,  it  fur- 
nished 30  per  cent,  of  benzoic  ether  (16  grms.  produced  5  grms.). 
The  formation  of  the  benzoic  ether  commenced  at  ¥12°  F.;  but  at 
this  temperature,  even  after  long  contact,  there  was  but  little  of  it. 
With  the  view  of  acquiring  greater  certainty  with  regard  to  the 
purity  of  the  ether  employed,  the  author  rectified  the  ether  puri- 
fied by  the  above  method,  distilling  only  the  half  of  it  at  a  fixed 
temperature;  the  distillation  was  then  repeated  upon  this  portion, 
only  collecting  the  half  of  the  product.  The  ether  thus  obtained 
furnished  25  per  cent,  of  benzoic  ether  after  three  hours'  contact 
with  the  acid  at  680°  F. 
Ether  and  butyric  acid,  kept  for  six  hours  at  690°  F.,  produced 
butyric  ether.  The  liquid  in  the  tubes,  submitted  to  distillation, 
only  furnished  ether,  water,  butyric  ether  and  butyric  acid.  No 
gas  was  evolved. 
At  the  same  temperature,  ether  and  palmitic  acid  produced  pal- 
mitic ether,  fusible  at  72°  F. 
In  these  instances  neither  the  acid  nor  the  ether  was  entirely 
combined,  whatever  might  be  the  excess  of  one  or  other  of  them. 
Ether  and  water,  heated  to  the  limit  of  decomposition  (842°  F.?), 
do  not  combine. 
II.  Direct  formation  of  the  Ethers  by  means  of  Alcohol  and  Acids. 
The  union  of  acid  and  alcohol  to  form  ether  is  effected  either 
directly  or  by  the  intervention  of  a  mineral  acid.  The  direct  com- 
