326 
PREPARATION  OF  SPIRIT  OF  NITROUS  ETHER. 
small  than  on  the  large  scale,  and  the  subsequent  solution  of  the 
ether  thus  produced  in  spirit,  in  the  one  case  in  the  proportion 
of  one  to  four,  and  in  the  other,  of  one  to  ten,  they  have  proved 
unsuited  for  the  purpose  of  the  manufacturer. 
In  the  British  Pharmacopoeia  of  1864  a  new  process  was  given 
for  this  preparation,  under  the  name  of  spirit  of  nitrous  ether,  and 
great  expectations  were  at  first  formed  with  respect  to  it.  I  need 
hardly  say  that  these  expectations  have  been  disappointed.  So 
much  has  been  published  by  myself  and  others  with  reference  to 
nitrate  of  soda,  and  its  proposed  use  in  the  manufacture  of  spirit 
o£  nitrous  ether,  that  it  will  be  sufficient  for  me  to  state  here, 
that  this  process  has  brought  us  no  nearer  than  we  were  before 
to  a  satisfactory  and  available  method  of  accomplishing  what  is 
required. 
I  have  been  engaged  for  a  considerable  time  in  submitting  the 
various  published  processes  for  nitrous  ether  and  sweet  spirit  of 
nitre  to  practical  trial  with  the  view  of  ascertaining  which  is  the 
best,  and  have  made  a  great  number  of  experiments  for  the  pur- 
pose of  discovering  a  more  satisfactory  method  of  obtaining  these 
products,  and  especially  the  latter  one,  than  any  of  those  hitherto 
adopted.  I  was  anxious  to  find  a  process  that  would  be  suitable 
for  the  Pharmacopoeia,  and  which,  at  the  same  time,  would  com- 
mend itself  to  the  manufacturer,  so  as  to  induce  its  general  adop- 
tion. To  fulfill  this  object  it  was  essential  that  the  process 
should  admit  of  application  without  difficulty  on  a  large  or  small 
scale,  with  similar  and  uniform  results,  yielding  a  product  re- 
sembling the  best  sweet  spirit  of  nitre  of  commerce,  at  a  cost 
not  exceeding  that  at  which  it  could  be  produced  by  any  other 
known  process.  In  the  different  attempts  which  have  been  made 
in  this  direction,  both  by  myself  and  others,  the  object  aimed  at 
has  been  to  set  up  a  chemical  action  that  can  be  regulated  and 
controlled,  so  that  while  nitrous  ether  is  produced  in  sufficient 
quantity  there  shall  not  be  an  undue  formation  of  secondary 
products  or  an  excessive  destruction  and  waste  of  alcohol  and 
nitric  acid,  as  frequently  occurs  in  the  ordinary  processes. 
It  has  been  proposed  to  effect  the  required  object,  (1)  by  add- 
ing the  nitric  acid  to  the  spirit  in  successive  quantities  as  the 
process  proceeds  ;  or  (2)  by  altering  the  strength  of  the  acid  ; 
