^m'ipS!;  i887arm" }    Estimation  of  Alkaloids  in  Extracts.  185 
(42)  1*0  extract  mix  vomica,  0*1  strychnine,  0*1  brucine,  3*0  water,  5 
drops  diluted  sulphuric  acid,  10*0  lime  yield  18  74  per  cent,  of  alkaloid, 
after  deducting  the  strychnine  and  brucine  added. 
Experiments  No.  38  to  42  furnish  proof  that  both  lime  and  ammonia 
answer  for  the  modified  process.  Whilst  titrating  it  was  noticed  that 
toward  the  end  the  reactions  were  not  so  distinct  as  with  the  other  ex- 
tracts, so  that  very  sensitive  test-paper  had  to  be  employed ;  furthermore 
crystals  of  alkaloid  separated  out  in  the  ethereal  solution  and  had  to 
be  redissolved  in  alcohol.  As  in  former  experiments  lime  again  proved 
preferable  to  ammonia  as  purer  alkaloidal  solutions  are  obtained  and 
more  readily  titrated. 
The  above  results  indicate  that  the  method  is  well  adapted  for 
estimating  the  amount  of  alkaloid  contained  in  the  extract,  but  it  re- 
quires very  exact  work,  and,  above  all,  a  complete  liberation  and  so- 
lution of  the  alkaloids. 
To  determine  whether  the  addition  of  lime,  owing  to  its  great  affinity 
for  water  would  prevent  the  complete  exhaustion  of  the  extract,  the 
extract  was  dissolved  in  normal  ammonia  and  mixed  with  lime, 
so  that  the  alkaloids  were  liberated  by  the  ammonia,  while  the  lime 
merely  took  up  moisture  and  coloring  matter,  and  by  uniform  incor- 
poration with  the  extract  rendered  it  fit  for  extraction.  The  following 
experiments  show  the  results  obtained  : 
(43)  20  extract  aconite,  2  cc.  normal  ammonia,  10  gm.  powdered 
lime,  yield  1*279  per  cent,  alkaloid  (compare  experiments  28,  29,  30). 
(44)  2  gm.  extract  belladonna,  2  cc.  normal  ammonia,  10  gm.  pow- 
dered lime  yield  1*156  per  cent,  alkaloid  (compare  experiments  17, 18, 
20,  21,  25). 
(45)  2  gm.  extract  hyoscyamus,  2  cc.  normal  ammonia,  10  gm.  powd. 
lime,  yield  0*766  percent,  alkaloid  (compare  experiments  34,  35,  36). 
(46)  1  gm.  extract  nux  vomica,  2  cc.  normal  ammonia,  10  gm.  powd. 
lime,  yield  18*74  per  cent,  alkaloid  (compare  experiments  38  to  42.) 
By  comparison  it  will  be  observed  that  the  same  quantities  were  ob- 
tained as  before,  proving  that  either  ammonia  or  lime  or  both  may  be 
used.  The  slight  difference  in  extract  of  hyoscyamus  is  due  to  the 
fact  that  a  new  extract  was  used,  it  having  been  omitted  to  reserve  a 
portion  of  the  original  extract.  The  process  practically  consists  in, 
firstly,  liberation  of  the  alkaloid  ;  secondly,  extraction  with  ether ; 
thirdly,  evaporation  of  the  ethereal  solution,  and  fourthly,  titration. 
Of  these,  the  third  requires  a  great  deal  of  attention. 
