ON  SWEET  SPIRIT  OF  NITRE. 
249 
ether  ordered,  it  should  in  reality  contain  only  one  per  cent.  It 
is  surely  time  that  variations  in  medicinal  preparations  were 
done  away  with — over  the  earth  if  possible — but  at  all  events,  at 
home ;  and  more  especially  such  variations  as  have  been  pointed 
out.  We  have  long  felt  the  necessity  of  calling  the  attention  of 
the  Society  to  this  preparation.  The  permission  by  the  Govern- 
ment to  employ  methylated  spirit  in  manufactures  gives  us  the 
opportunity. 
All  the  formulae,  however  numerous,  given  for  the  preparation 
of  Sp.  Eth.  Nit.,  arrange  themselves  under  one  or  other  of  three 
modes,  having  for  their  result  a  mixture  of  hyponitrous  ether 
and  strong  alcohol,  and  are  but  modifications  of  one  and  the 
same  process — namely,  the  production  of  hyponitrous  acid  by 
the  action  of  nitric  acid  upon  an  excess  of  alcohol.  N05  is  made 
to  act  upon  alcohol  indirectly  or  directly.  Either  the  NQ5  is 
eliminated  from  a  salt  containing  it  while  in  contact  with  strong 
alcohol,  or  the  acid  first  freed  from  combination  is  added  to  the 
alcohol.  The  third  mode  is,  first,  the  preparation  of  hyponitrous 
ether,  and  then  its  solution  in  rectified  spirit;  The  second  of 
these  modes  is  that  followed  by  the  London  Pharmacopoeia,  and 
the  third,  that  by  the  Edinburgh  and  Dublin. 
The  action  of  N05  upon  alcohol  ought  to  receive  an  investi- 
gation such  as,  so  far  as  we  know,  it  has  not  hitherto  met  with  ; 
for  although  the  number  of  products  formed  and  separated  are 
numerous,  yet  the  precise  conditions  which  give  origin  to  these 
are  not  sufficiently  defined ;  a  few  degrees  more  or  less  of  heat, 
or  an  acid  more  or  less  strong,  modify  the  results.  But  we  con- 
fess the  investigation  to  be  most  difficult.  What  we  have  to  do 
with  at  present  is  the  result  of  the  action  of  N05  upon  rectified 
spirit,  as  it  offers  itself  to  us  in  the  preparation  of  the  Sp.  Eth. 
Nit.  of  the  Pharmacopoeias.  The  products  of  that  action  divide 
themselves  into  three  groups,  one  of  which  passes  off  in  the 
state  of  gases ;  another  abides  in  the  flask  or  retort ;  and  the 
third,  that  with  which  we  have  to  deal,  passes  over  into  the  re- 
ceiver. According  to  the  London  formula,  we  will  have  in  the 
receiver  a  finished  product,  requiring  no  more  to  be  done  to  it, 
consisting  of  a  solution  of  impure  hyponitrous  ether,  containing 
aldehyde,  in  a  very  strong  rectified  spirit.  By  the  Edinburgh 
and  Dublin  formulae  we  have  a  product  which  has  yet  to  undergo 
