ATaS"r'yPSm'}       Substitute  for  Ethyl  Alcohol.  n 
bath  until  the  chloroform  and  ammonia  are  completely  dissipated. 
Then  10  c.c.  of  decinormal  sulphuric  acid  is*  added,  stirred, 
diluted  with  20  c.c.  of  hot  water,  and  when  solution  is  complete 
2  c.c.  of  brazilwood  indicator  is  added.  Centinormal  potassium 
hydrate  is  added  until  a  permanent  pinkish  color  is  produced.  The 
number  of  cubic  centimetres  of  potassium  hydrate  required  is 
divided  by  10,  the  number  found  is  subtracted  from  10,  and  the 
remainder  is  multiplied  by  0-0364,  and  that  product  by  50,  which 
will  give  the  percentage  of  total  alkaloids  in  the  2  grammes  of 
extract  taken,  it  being  assumed  that  strychnine  and  brucine  are 
present  in  equal  proportion,  and  the  above  factor  being  found 
by  taking  the  mean  of  their  respective  molecular  weights 
(334  +  394  h-  2  =  364). 
This  very  well  designed  method  was  found  impracticable  in  the 
writer's  hands,  through  difficulty  in  carrying  out  the  details.  The 
first  obstruction  encountered  was  the  very  nearly  constant  emulsi- 
fying of  the  chloroform  and  the  constant  refusal  of  the  liquids  to 
separate  on  standing,  and  the  difficulty  and  loss  of  time  in  man- 
aging an  emulsion  once  formed.  The  U.S. P.  directs  the  immiscible 
liquids  to  be  "  agitated,"  not  shaken ;  yet  if  shaking  be  avoided 
and  the  agitation  be  ever  so  cautiously  managed  some  emulsion 
seems  unavoidable,  whilst  a  degree  and  kind  of  agitation  that  is 
short  of  shaking  washes  out  the  alkaloids  imperfectly.  Emulsions 
that  did  form  were  best  managed  by  running  them  out  into  a  cap- 
sule, driving  off  the  chloroform  on  a  water-bath,  returning  the  dark 
liquid  to  the  separator,  and  managing  the  next  chloroform  with 
greater  care.  But  a  better  expedient  was  found  in  a  recommen- 
dation of  A.  H.  Allen  and  others,  to  use  a  mixture  of  equal  volumes 
of  chloroform  (99  per  cent.)  and  ether  (96  per  cent.).  With  this 
mixture,  used  in  large  quantity,  vigorous  shaking  and  consequent 
effective  washing  may  be  employed  with  little  emulsion,  if  any,  at 
the  last  of  the  washings,  the  separations  being  very  prompt  and 
sharp,  usually  ready  to  draw  off  within  half  an  hour  after  shaking. 
The  clear  chloroform  and  ether  solutions  are  better  managed  if 
drawn  off  into  and  boiled  off  from  a  flask,  as  the  dissolving,  the 
heating  up  and  the  titration  are  more  easily  done  in  a  flask.  The 
solution  to  be  titrated  is  always  of  a  full  yellow  color,  from  a  bright 
pale  yellow  to  a  deep  yellow,  with  a  reddish  tint  by  reflected  light, 
a  color  in  which  the  first  increase  of  pinkish  tint  is  difficult  to 
