4  Substitute  for  Ethyl  Alcohol.        { A jaSarryPi9oorm' 
touched  to  the  solution  and  held  in  contact  for  about  ten  seconds. 
Then  on  close  inspection  a  bluish  tinge  was  perceptible,  indicating 
the  finished  titration. 
12  c.c.  of  decinormal  acid  had  been  taken  and  0  30  c.c.  of  deci- 
normal  alkali  had  been  required  to  saturate  the  uncombined  acid, 
leaving  11-70  c.c.  saturated  by  the  alkaloid  of  belladonna. 
The  molecular  weight  of  atropine  being  288-38,  the  calculation 
for  the  result  was  : 
[  1 1 70  =  -3374046  X  2  =  '67481  =  0-675  per  cent. 
Duplicate  assay  0*685  " 
1  -360  ~  2  = 
•680  average 
For  the  many  assays  needed  in  the  design  of  this  paper  a  shorter 
assay  process  was  needed,  and  one  that  could  be  applied  to  the 
differing  fractions  of  percolate  without  too  much  sacrifice  in  accu- 
racy of  results.  Such  a  process  the  new  acetic  acid  menstruum 
seems  to  have  supplied  by  taking  the  basis  or  design  of  the  older 
process  and  cutting  out  some  steps  that  could  be  shown  to  be  dis- 
pensable. 
THE  NEWER  ASSAY  PROCESS. 
Ten  grammes  ot  the  unpeeled  belladonna  root,  in  No.  60  powder, 
was  equally  moistened  with  5  c.c.  of  10  per  cent,  acetic  acid,  the 
moistened  powder  was  lightly  packed  in  an  extractor — A.  J.  P., 
1899,  p.  312;  Ephemeris,  p.  2313 — (or  some  equivalent  percolator), 
was  filled  to  saturation  with  10  per  cent,  acetic  acid,  was  allowed  to 
digest  for  twenty-four  hours,  and  was  then  percolated  to  exhaustion, 
yielding  about  200  c.c.  of  percolate. 
This  percolate  was  evaporated  on  a  hot  water-bath  to  an  extract 
that  was  hard  when  cold,  and  weighed  3*96  grammes. 
This  extract  was  dissolved  in  20  c.c.  of  a  mixture  of  equal  vol- 
umes of  91  per  cent,  alcohol  and  10  per  cent,  water  of  ammonia,  the 
solution  transferred  to  a  separator,  20  c.c.  of  chloroform  added,  the 
whole  well  shaken  for  five  minutes,  allowed  to  separate  and  the 
chloroform  stratum  drawn  off  into  a  beaker. 
During  the  time  required  for  separating,  the  wetted  end  of  a  strip 
of  neutral  or  acid  litmus  paper  was  held  in  the  vapor  space  of  the 
separator  in  order  to  be  sure  of  the  full  alkalinity  of  the  contents. 
