508 
Examination  of  Engeuol. 
'Am.  Jour.  Pharm. 
I        Oct.,  1892. 
several  tests  are  to  be  compared  as  to  relative  quantities  or  residual 
albumen,  should  there  be  any,  the  flasks  should  be  rapidly  cooled 
to  below  6o°  F.  In  determining  the  power  of  different  pepsins,  the 
only  allowable  variation  from  above  formula  should  be  the  propor- 
tion of  pepsin — of  a  pepsin  testing  i  :  2,500  in  6  hours,  0-008  gm. 
would  be  required  to  do  the  work  of  o-oi  gm.  of  a  pepsin  testing 
1  : 2,000  by  the  6-hour  test. 
Generally  the  operator  knows  enough  about  a  pepsin  to  be 
assayed,  to  judge  closely  as  to  the  quantity  to  use.  In  any  event  he 
can  soon  determine  by  one  assay  whether  or  not  a  given  brand  is 
of  the  power  claimed  for  it.  If  nothing  is  known  about  a  pepsin 
to  be  assayed,  one  test  with  0  01  gm.,  another  with  more,  and  a 
third  with  less  of  the  pepsin,  can  be  made  simultaneously,  and 
judgment  formed  from  results  about  the  quantity  required  for  the 
final  test.  As  a  safeguard,  and  especially  to  provide  against  varia- 
tions in  albumen,  it  is  advisable  always  to  carry  through  one  control 
test  with  a  pepsin  of  known  power. 
When  several  tests  are  to  be  made  of  one  brand  of  a  soluble 
pepsin,  or  when  minute  quantities  cannot  be  accurately  weighed,  it 
is  often  an  advantage  to  make  a  solution  of  a  known  quantity  of 
pepsin  in  acidulated  water,  bringing  the  solution  to  a  known 
volume.  By  this  means  any  required  quantity  of  pepsin  can  be 
accurately  and  quickly  apportioned  by  measure.  In  such  cases  01 
gm.  of  pepsin,  plus  acidulated  water  (containing  o-2  per  cent.  HC1) 
sufficient  to  measure  ico  cc,  makes  a  solution  of  which  I  gm. 
pepsin  is  represented  by  1,000  cc. 
ESTIMATION  OF  EUGENOL  IN  OIL  OF  CLOVES. 
By  Joseph  C.  de  la  Cour,  Ph.G. 
From  an  Inaugural  Essay. 
The  method  proposed  by  H.  Thorns  (Phar.  Centralhalle,  1891,  p. 
589)  for  the  estimation  of  eugenol  is  based  upon  the  formation  of 
benzoyl-eugenol,  and  is  carried  out  as  follows  :  5  gm.  of  the  oil,  20  gm. 
oi  solution  of  sodium  hydrate  and  6  gm.  benzoyl  chloride  are  placed  in 
a  tared  beaker  of  1 50  cc.  capacity  and  thoroughly  mixed ;  the  mixture 
becomes  quite  hot,  and  after  it  has  cooled  again,  50  cc.  water  are 
added  and  heat  is  applied  until  the  crystalline  mass  melts,  after 
which  the  mixture  is  again  allowed  to  cool  ;  the  clear  liquid  is  run 
