Am.  Jour.  Pharm. 
March,  1908. 
Alcohol  in  Concentrated  Nitrous  Ether. 
103 
Another  form  by  which  I  obtained  good  results  consisted  of  a 
bulb  thistle  tube  connected  at  the  top  by  a  large  glass  spiral  and 
at  the  bottom  by  the  flask  containing  the  nitrous  ether.  Water 
was  placed  in  the  spiral  in  such  a  way  that  it  remained  at  the  bot- 
tom of  each  turn  ;  water  was  also  placed  in  the  bulbs  of  the  thistle 
tube.    (Fig.  2.) 
The  later  apparatus  used  was  merely  a  series  of  five  tall  wash- 
bottles,  three-quarters  filled  with  water,  with  the  outlet  of  each  bottle 
reaching  nearly  to  the  bottom  of  the  next  bottle.  This  form  has 
simplicity  as  its  chief  advantage,  and  also  temperature  conditions 
can  be  carefully  controlled. 
In  any  of  the  above  apparatus  at  least  three  days  should  be 
allowed  for  the  evaporation  of  the  concentrated  nitrous  ether. 
When  volatilization  is  complete,  the  water  in  the  apparatus  is 
combined  and  put  in  a  measuring  flask  of  such  size  that,  when  diluted, 
20  c.c.  of  it  will  contain  from  o-i  gramme  to  0  3  gramme  of  alcohol. 
The  apparatus  is  carefully  washed  with  ice- water,  and  washings 
added  to  measuring  flask,  making  the  proper  volume. 
After  mixing  well  the  combined  washings  and  dilute  solution 
of  alcohol  from  the  apparatus,  20  c.c.  are  accurately  measured  into 
a  clean  magnesium  citrate  bottle  which  can  easily  be  obtained 
with  a  tight  stopper.  This  solution  contains  the  alcohol  and 
some  nitrous  ether,  depending  on  the  form  of  apparatus  used 
and  the  rate  of  volatilization.  The  proper  amount  of  oxidizing 
agent  must  now  be  added  to  destroy  the  nitrous  ether  and  ioc.c. 
more  of  the  chromic  acid  mixture  added  to  change  the  alcohol  pres- 
W/VTER;' 
LAYER.   
