I  IO 
Assay  of  Belladonna  Leaves. 
f  Am.  Jour.  Pharm 
t      March,  1899. 
mixture  consisting  of  10  c.c.  water  and  io  c.c.  water  of  ammonia 
(10  percent,);  the  extract  mixture  was  put  into  a  glass-stoppered 
bottle  of  250  c  c.  capacity,  and  the  beaker  rinsed  with  the  remainder 
of  the  diluted  ammonia  water  used  in  portions.  Into  this  bottle 
were  then  weighed  60  grammes  ether  and  15  grammes  chloroform, 
the  mixture  agitated  continuously  for  ten  minutes,  and  set  aside 
for  ten  minutes,  when  the  ether-chloroform  solution  was  poured  off 
as  completely  as  possible  into  a  clean,  dry  flask,  weighed  and  set 
aside  for  one-half  hour.  As  much  as  possible  of  the  ether-chloro- 
form solution  was  then  poured  into  the  separatory  funnel,  the  flask 
and  residual  contents  weighed  (to  ascertain  the  weight  of  the  trans- 
ferred solution)  and  the  assay  proceeded  with,  as  described  under 
the  assay  of  the  leaves.  The  quantity  of  extract  used  for  the  com- 
pletion of  the  assay  was  calculated  by  the  following  proportion: 
75  gm.,  wt.  of  .  wt  of  extract  started  with  .  .  wt.  of  transferred  .  x 
solvent  used  portion. 
In  the  assay  of  the  extract  from  the  English  cultivated  leaves  it 
was  found  that  the  first  portion  of  25  c.c.  of  acidulated  water  did 
not  cause  an  acid  reaction,  so  that  40  c.c.  were  used  in  the  first  por- 
tion, followed  afterwards  by  three  portions  of  5  c.c.  each. 
EMPLASTRUM  BELLADONNA,  U.S. P.,  I  89O. 
As  stated  before,  as  soon  as  the  extract  of  belladonna  was  obtained 
of  the  proper  consistency  it  was  weighed,  mixed  and  portions 
weighed  off  for  the  various  determinations  and  for  the  making  of 
the  plaster.  Forty  grammes  each  of  resin  plaster  and  soap  plaster 
(purchased  from  a  manufacturing  house)  were  melted  in  a  weighed 
evaporating  dish  placed  on  a  water-bath  and  20  grammes  of  the 
extract,  weighed  on  a  watch  crystal,  incorporated  by  heating  on  the 
water  bath  whilst  constantly  stirring ;  unnecessary  heating  was 
avoided,  but  still  a  loss  of  about  1  per  cent,  was  noticed  in  each 
case;  by  weighing  the  contents  of  the  dish  before  adding  the  ex- 
tract a  loss  of  0  3  to  o  4  grammes  was  noticed,  so  that  the  greater 
portion  of  the  loss  is  due  to  the  moisture  in  the  extract  used.  In 
the  Pharmacopoeia  this  loss  in  making  Belladonna  Plaster  has  not  been 
recognized. 
Assay  of  the  Plaster. — After  several  unsuccessful  trials  of  what 
seemed  possible  methods,  the  following  was  decided  upon  and  found 
to  give  conforming  results.  It  depends  upon  the  decomposition  of 
the  soap  and  of  the  lead  salts  by  sulphuric  acid,  and  from  calcula- 
