Amo™\££m'}  Spiritus  Mtheris  Nitrosi.  507 
There  is  first,  an  ethereal  fluid,  so  designated  ;  secondly,  an  ethereal 
oil  or  hydrocarbon  ;  thirdly,  aldehyd  ;  fourthly,  nitrous  acid,  uncom- 
bined  ;  fifthly,  acetic  acid  uncombined  ;  sixthly,  alcohol  and  water. 
The  presence  of  nitrite  of  ethyl  in  the  spirit  of  the  Pharmacopoeia 
has  been  denied  ;  and  I  am  willing  to  admit  it  may  be  possibly  true, 
but  if  true,  it  is  culpably  wrong,  and  it  is  the  result  of  mismanage- 
ment. If  no  nitrite  of  ethyl  be  formed,  what  becomes  of  the  nitric 
acid  used  in  the  operation,  and  what  are  the  products  of  the  chemical 
action  that  takes  place  ?  It  does  not  distil  over,  it  does  not  pass  away 
as  gas,  but  it  is  nevertheless  consumed. 
After  many  attempts  to  investigate  this  matter,  and  trying  all  the 
methods  that  suggested  themselves  to  me,  or  that  I  could  find  described 
for  the  estimation  of  the  nitrites,  I  found  none  that  gave  satisfactory 
results  until  I  adopted  the  following  scheme,  by  which  not  only  the 
nitrite  of  ethyl,  but  all  the  other  constituents,  may  be  accurately  esti- 
mated. 
The  following  table,  at  all  events,  shows  the  results  in  two  analyses 
(out  of  a  great  many  others)  of  a  typical  sample,  agreeing  with  the 
B.P.  test,  etc.: 
(1.) 
w 
Water, 
7-96 
7*93 
Aldehyd, 
1-19 
119 
Alcohol, 
88-io 
88*10 
Acetic  Acid, 
•47 
•50 
Nitrous  Acid, 
•59 
•56 
Nitrite  of  Ethyl, 
1*69 
1-72 
I00"00 
IOO'OO 
The  method  of  analysis  is  as  follows  : 
The  nitrite  of  ethyl  is  to  be  estimated  by  the  conversion  of  its 
nitrogen  into  ammonia,  first  by  decomposing^  with  pure  potash  into 
KN02>  and  distilling  this  with  a  zinc  and  copper  couple  somewhat 
after  the  method  recommended  by  Thorpe,  but  modified  by  Dr.  Cor- 
nelius Fox,  and  titrating  the  result  with  standard  acid  (process  in  detail 
given  below). 
The  amount  of  nitrous  and  acetic  acids  are  estimated  volumetri- 
cally.    The  two  acids  are  afterwards  separately  estimated. 
Aldehyd  is  estimated  by  conversion  into  acetic  acid  by  peroxide  of 
hydrogen,  and  titrated. 
Water  and  alcohol  by  difference. 
