Am.  Jour.  Pharm.  1 
July,  1877.  / 
Spirit  of  Nitrous  Ether. 
361 
I  believe  to  be  true  also  for  the  smaller  quantities  of  distillate  obtained 
in  my  experiments,  since  the  spirits  made  with  them  corresponded  very 
closely  with  the  product  of  the  second  experimental  distillation,  and  all 
of  them  corresponded  with  the  officinal  spirit  in  every  character,  except 
specific  gravity.  The  question  now  properly  arises,  how  or  in  what 
manner  the  temperature  affects  the  volume  of  distillate  without  at  the 
same  time  affecting  the  quantity  of  ether  ?  This  also  permits  of  easy 
explanation.  In  both  processes  a  very  large  excess  of  alcohol  is  used 
(see  tables  D  and  E).  The  formation  of  nitrous  ether  takes  place  as 
readily  at  the  lower  as  at  the  higher  temperature,  but  at  the  higher 
temperature  the  reaction  is  more  violent,  and,  being  also  much  nearer 
the  boiling  point  of  alcohol,  a  relatively  larger  quantity  of  the  alcohol, 
not  necessary  to  the  reaction,  is  carried  over. 
The  first  question  may  therefore  be  answered  as  follows: 
1 .  //  is  possible  to  obtain  the  quantity  of  distillate  required  by  the  "  Phar- 
macopoeia" Whether  this  is  possible  without  unnecessarily  long-continued 
heating,  as  in  the  instance  of  the  "  second  experimental  distillation"-  is  not 
decided  by  the  above  experiments,  but  seems  probable. 
2.  It  is  not  necessary  to  obtain  the  full  quantity  of  distillate  required  by 
the  a  Pharmacopoeia."  If  the  reaction  takes  place  at  a  lower  temperature 
the  yield  is  smaller,  but  the  etherification  is  complete  and  the  distillate  more 
concentrated  than  at  a  higher  temperature,  at  which  a  correspondingly  larger 
quantity  of  undecomposed  alcohol  is  carried  over  with  the  ether  vapor. 
II.    Is  THE  SPECIFIC  GRAVITY  OF  SPIRIT  OF  NITROUS  ETHER,  U.  S.  P., 
CORRECTLY  STATED  ? 
The  "  Pharmacopoeia  "  states  that :  Ck  Spirit  of  nitrous  ether  has  a 
specific  gravity  of  0*837. "  On  looking  over  the  IC  Journals,"  I  find 
that  only  two  experimenters,  Oakley  Griggs1  and  Geo.  W.  Kennedy,2 
have  recorded  the  specific  gravity  of  nitrous  ether  obtained  by  them 
since  the  publication  of  the  present  "  Pharmacopoeia,"  but  neither  of 
them  gives  the  details  of  the  process  as  carried  out.  The  sp.  gr.  of 
Mr.  Griggs'  product  is  stated  to  be  0*834  ;  that  of  Mr.  Kennedy's, 
0*835.  I  have  already  stated  that  the  three  products  obtained  by  me 
corresponded  in  all  their  characters  with  the  officinal  requirements, 
except  in  their  specific  gravities  :  the  product  of  the  first  distillation 
-"A.  J.  Ph.,"  Oct.,  1875,  P-  463'        2  Ibid.,  June,  1876,  p.  259. 
