Am.  Jour.  Pharm, 
June,  1898. 
}     Amy  I  Nitrite  and  Nitrous  Ether. 
283 
they  may  contain,  which  is  easily  done.  Potassium  chlorate  and 
nitric  acid,  in  their  commercial  forms,  nearly  always  contain  chlo- 
ride, but  they  can  readily  be  obtained  free  from  it.  Ammonium 
ferric  sulphate  may  also  contain  chloride  in  traces.  Nitric  acid  may 
contain  lower  oxides  of  nitrogen,  indicated  by  a  yellow  color  of  the 
acid  and  brown  vapors  in  the  air-space  of  the  container.  The  cor- 
rection is  most  readily  made  by  mixing  these  reagents  in  the  same 
quantities  as  used  in  the  assay  and  allowing  the  mixture  to  stand 
N 
a  while.    If,  on  the  addition  of  a  few  drops  of  —  silver  nitrate,  only 
10 
a  slight  opalescence  appears,  no  correction  is  necessary ;  if  the  solu- 
tion becomes  decidedly  turbid  or  a  precipitate  is  formed,  a  known 
volume  of  silver  nitrate  should  be  added  and  the  excess  determined 
with  sulphocyanate.  The  silver  nitrate  required  to  precipitate  the 
chloride  is  deducted  from  that  required  in  the  actual  assay. 
Commercial  Samples. — The  samples  reported  upon  below  were 
purchased  in  original  packages  in  the  open  market  and  fairly  repre- 
sent the  American  market.  They  were  assayed  by  both  the  U.S. P. 
and  the  new  chlorate  method,  and  also  subjected  to  the  other  phar- 
macopceial  tests.  The  acidity  is  given  in  terms  of  nitrous  acid  for 
the  sake  of  convenience,  although  it  is  not  known  that  the  free  acid 
consists  entirely  of  this.  For  the  same  reason  no  deduction  is  made 
from  the  percentage  of  ethereal  nitrite,  for  the  free  nitrous  acid 
included  in  the  estimations  as  ethyl  or  amyl  nitrite. 
SPIRIT  OF  NITROUS  ETHER. 
No. 
P.  C.  Strength  by 
U.S.P.  Method. 
3'66;  370 
4-84;  4-88 
4-28;  4-31 
3*95;  4'oo 
4'35;  4"32 
85-5;  85-9 
P.  C.  Strength  by  Chlo-  Per    Cent,  of 
rate  Method.  Free  Acid. 
4-o6;  4-oi 
5"3o;  5'3o 
4-58;  4-60 
4-38;  4-44 
4"8i;  4^84 
92*6;  92  o 
0T4 
o-ii 
o-45 
0-15 
0-31 
0*46 
Aldehyde. 
Faintly  yellow 
Dark 
Straw  " 
Dark 
Straw 
(Tested  after  dilution 
to  4  per  cent. ) 
*  Concentrated  nitrous  ether,  stated  to  be  90  per  cent,  ethyl  nitrite. 
N 
The  acid  determinations  were  made  with  —  soda,  with  phenol- 
phthalein  as  indicator  and  without  dilution  with  water.  When  water 
