380 
Spiritus  JEtheris  Nitrosi. 
Am.  Jour.  Pharm. 
July,  1884. 
1st.  Increase  of  specific  gravity. 
2d.  Diminution  of  the  volume  of  ethereal  liquid  separated  by  satu- 
rated chloride  of  calcium  solution. 
3d.  Development  of  acidity. 
The  extent  of  these  changes  we  shall  consider  in  their  order. 
Increase  of  Specific  Gravity, — In  the  following  table  I  give  results 
of  observations.  I.  to  V.  are  B.P.  spirit  made  by  myself  or  procured 
as  such.  VI.  is  spirit  answering  B.P.  tests  raised  to  '850  with  water, 
and  VII.  is  the  "850  of  London  Pharm acopceia. 
Made. 
When  examined. 
Sp.  gr.  50°  F. 
I. 
Not  known. 
May,  1883. 
•848 
I. 
Not  known. 
March,  1884. 
•853 
IL 
Not  known. 
May  1883. 
•852 
II. 
Not  known. 
March,  1884. 
•8576 
III. 
Nov.,  1883. 
March,  1884. 
•852 
IV. 
Received  Nov.,  1883. 
March,  1884. 
•8516 
v. 
Feb.  14,  1884. 
Feb.  14,  i884. 
•846 
A'. 
Feb.  14,  1884. 
Feb.  21, 1884. 
•850 
V. 
Feb.  14,  1884. 
March,  7, 1884. 
•8516 
VI. 
Feb.  15, 1884. 
March  7,  1884. 
•8536 
VII. 
Received  Nov.,  1883. 
Feb.  14, 1884. 
•856 
VII. 
Received  Nov.,  1883. 
March  7, 1884. 
•859 
Diminution  of  Separation  Volume. — In  this  I  give  the  result  of 
examination  of  two  specimens  of  the  B.P.  spirit  kept  under  different 
conditions,  a  in  a  well  stoppered  and  almost  full  bottle,  which  was 
opened  frequently,  and  /3  kept  in  a  badly  stoppered  bottle,  half  full, 
and  between  the  second  and  third  observations  the  stopper  was  acci- 
dentally left  out  over  a  night. 
o.  February  14.  2     p.  c.  j  p.  February  14.  2     p.  c. 
February  21.  1-75  p.  c.  j       February  18.  1*33  p.  c. 
March       7.  T33  p.  c.  |       February  21.  Ml. 
It  will  be  convenient  to  reserve  remarks  on  these  observations  until 
we  consider : 
The  Development  of  Acidity. — The  free  acids  existing  in  the  spirit 
are  acetic  and  nitrous  acids.  It  has  been  stated  that  nitric  acid  is  also 
present,  but  the  ordinary  methods  for  determining  the  existence  of 
