382 
Spiritus  ^Etheris  Nitrosi. 
(Am.  Jour.  Pharm. 
\       July,  1884. 
Date  or  age. 
HNOo 
HC2H302. 
C2H5NOo. 
CoH40. 
I. 
May,  1883. 
0-47 
1-20 
0-87 
0-80 
I. 
March,  1883. 
0-773 
0-329 
0  -095 
2-50 
II. 
One  week 
0-215 
0-206 
3-54 
0-85 
II. 
Two  weeks. 
|     •  0  -257 
0-247 
0-95 
II. 
Three  weeks. 
0-274 
0-349 
3-14 
III. 
Two  days. 
2-01 
0-80 
III. 
Four  days. 
0-24 
0-216 
1-14 
III. 
One  week. 
0-322 
0'246 
1-24 
2-00 
IV. 
One  month. 
0-247 
0-411 
l'93 
1  -67 
V. 
Four  months. 
0-161 
0-288 
3-53 
1-5 
VI. 
Four  months. 
0-352 
0-494 
1-64 
1-426 
VII. 
Four  months. 
0*418 
0-206 
0-92 
2-5 
VIII. 
Four  months. 
0-194 
0-247 
0-22 
0-2 
IX. 
As  received. 
0  -188 
0-42 
Ethyl  nitrite,  it  is  well  known,  is  a  very  volatile  fluid,  and  if  the 
spirit  be  stored  in  imperfectly  closed  bottles,  considerable  loss  will 
result  from  evaporation.  But  this  does  not  account  for  the  specific- 
gravity,  for  since  ethyl  nitrite  is  of  greater  density  than  spt.  sether.  nit., 
the  loss  by  evaporation  would  tend  to  decrease  rather  than  increase  the 
density  of  the  spirit.  Although  Dr.  Dupre"  has  stated  (see  paper 
quoted)  that  the  acidity  of  the  official  spirit  is  not  due  to  decompo- 
sition of  ethyl  nitrite,  yet  all  pharmacists  who  have  studied  this  sub- 
ject have  recognized  the  text-book  statement,  that  the  water  contained 
in  the  rectified  spirit  used  in  the  preparation  reacts  with  the  ethyl 
nitrite  to  form  alcohol  and  nitrous  acid.  A  further  change  takes  place 
in  which  acetic  acid  is  one  of  the  products,  and  since  the  aqueous  solu- 
tions of  these  acids  are  supernormal,  they  will  tend  to  increase  the 
specific  gravity,  and  as  ethyl  nitrite  disappears  in  their  formation,  the 
separation  volume  necessarily  decreases.  Independent  of  the  reaction 
between  water  and  ethyl  nitrite  another  reaction  takes  place,  in  which 
acetic  acid  is  formed.  What  is  this  reaction  *?  Oxidation  of  aldehyde,  is  a 
natural  reply,  and  to  this  oxidation  the  formation  has  generally  been 
attributed.  But  it  will  be  observed  from  the  acidity  table  that  alde- 
hyde is  an  increasing  rather  than  decreasing  factor,  as  we  should  in 
these  circumstances  expect.   This  is  particularly  observable  in  the  case 
