Am.  Jour.  Pharm.  ) 
November,  1920.  ) 
Abstracts  from  Theses. 
80 
potassium  sulphocyanate  solution  in  the  usual  manner,  and  calculated 
from  the  per  cent,  of  phosphoric  acid. 
By  eliminating  the  variable  factor,  the  zinc  oxide,  concordant 
results  have  been  obtained  in  a  number  of  assays  in  the  hands  of 
different  operators. 
MODIFIED  METHOD  FOR  PREPARING  KTHYL  NITRATE. 
In  a  thesis  prepared  in  the  Pharmacy  Laboratory,  Charles  H. 
Pitt  states  the  use  of  a  separatory  funnel  for  the  collection  of  ethyl 
nitrite  as  it  floats  upon  the  surface  of  the  saturated  sodium  sulphate 
solution,  as  directed  by  the  U.  S.  P.  IX,  has  not  proven  satisfactory 
in  the  hands  of  many  operators.  The  chief  objection  is  the  large 
loss  from  evaporation  during  the  process.  To  overcome  this,  where 
the  distillation  method  is  not  available,  Mr.  Pitt  has  devised  an 
apparatus  which  largely  prevents  loss  from  evaporation.  He  pro- 
ceeds as  follows: 
Two  large  flasks  are  placed  in  ice-baths,  and  the  one  closed  by  a 
doubly  perforated  stopper.  Through  one  perforation  a  thistle  tube 
(or  a  glass  tube  connected  at  the  top  by  a  piece  of  rubber  hose  with 
a  small  funnel)  is  inserted,  so  that  it  extends  almost  to  the  bottom 
of  the  flask.  A  second  tube,  bent  at  a  right  angle  an  inch  above  the 
stopper  is  inserted  in  the  other  perforation  and  just  passed  through 
the  stopper.  This  tube  is  again  bent  at  a  right  angle  and  the  outlet 
end  inserted  in  the  second  flask,  extending  almost  to  the  bottom. 
The  reaction  between  the  sodium  nitrite,  alcohol,  and  sulphuric 
acid  is  now  carried  on  as  usual,  in  the  cold  first  flask,  and  when  the 
strata  of  ethyl  nitrite  has  collected  on  the  surface  of  the  mixture 
in  the  flask,  more  water  is  carefully  poured  in,  through  the  funnel 
tube,  until  it  forces  the  ethyl  nitrite  over  into  the  second  flask, 
through  the  connecting  tube.  Now  the  tubes  are  reversed,  and  the 
washing  with  sodium  carbonate  solution  accomplished  in  the  second 
flask  the  ethyl  nitrite  being  subsequently  returned  to  the  first  flask 
by  adding  water  as  before,  the  first  flask  having,  of  course,  been 
cleaned.  It  is  now  washed  with  cold  water  as  before,  and,  when 
finally  treated  with  potassium  carbonate  is  ready  for  dilution  with 
alcohol  for  the  preparation  of  the  spirit. 
Distillation  flasks,  with  a  side  tube,  may  to  advantage  replace 
the  usual  Florentine  or  Erlenmeyer  flasks  whereby  the  contact 
with  a  rubber  stopper  is  avoided. 
By  this  method  practically  all  loss  by  evaporation  is  avoided 
