8  Preparation  of  Spirit  of  Nitrous  Ether,  {  jlrisso""* 
that  the  action  of  the  acid  upon  the  alcohol  must  be  moderated  if  ebul- 
lition should  take  place  too  rapidly,  which  is  sometimes  the  case  when 
the  temperature  approaches  6o°F.  This  can  easily  be  accomplished  by 
placing  the  bottle  containing  the  acid  and  alcohol  in  water,  the  temper- 
ature of  which  is  below  50°F.  I  have  found  it  to  be  a  convenient 
plan  to  allow  the  water  from  the  hydrant  (the  temperature  of  which  at 
this  time  is  50°F.)  to  run  on  the  bottle  for  about  half  an  hour,  when 
the  action  will  be  checked. 
Another  method  by  which  nitrous  ethers  can  be  made,  and  which 
requires  less  attention,  is  as  follows  :  Place  4J  parts  by  weight  of 
nitric  acid  in  a  vessel  of  similar  proportions  to  the  one  used  in  the  first 
process,  and  with  a  long-necked  funnel  pour  into  it  with  care  2  parts  of 
water  so  as  not  to  mix  with  the  acid,  and  on  this  pour  4J  parts  of  alco- 
hol in  the  same  manner  so  as  not  to  mix  with  the  water.  There  will 
be  three  distinct  layers  at  first,  but  having  placed  this  in  a  cool  place, 
and  under  the  same  conditions  as  before  described,  there  will  be  found 
in  two  or  three  days  only  2  layers,  the  upper  one  being  impure  nitrous 
ether.  This  is  to  be  treated  in  the  same  manner  as  in  the  previous 
process. 
The  great  volatility  of  nitrous  ether  renders  it  necessary,  in  order 
to  avoid  loss,  that  all  vessels  used  during  the  purifying  process  should 
be  maintained  at  a  temperature  below  6o°F. 
I  would  also  state  that  by  the  first  process  named  572  grains  pure 
ether  were  produced,  having  a  specific  gravity  of  about  '908  and  boil- 
ing at  62°F. 
I  prefer  the  first  named  method  for  making  nitrous  ether,  the  yield 
by  it  being  larger  and  sufficiently  great,  even  with  my  imperfect  appa- 
ratus, to  produce  spirit  of  nitre  at  a  cost  not  above  that  of  the  best 
commercial  article. 
Before  giving  -908  as  the  specific  gravity  of  nitrous  ether,  I  wish  to 
rectify  it  over  chloride  of  calcium  or  quick  lime.'  The  spirit  of  nitre 
produced  by  either  process,  mixed  with  ammonia,  does  not  become  yel- 
low, does  not  discolor  with  solution  of  potassa,  and  does  not  effervesce 
on  the  addition  of  a  carbonate.  , 
^  Liebig  gives  the  specific  g  av'tv  of  nitrous  ether  at  i5"C.  (59°F.)  at  '947,  and 
its  boili  ig  point  at  i6-4°C.^6i'5°F. — Editor 
