522  Assay  Processes  of  the  U.  S.  P. 
^  ''I  \  November,  1911. 
Ferrum  Reductum. — The  assay  process  could  be  improved  on. 
Gelsemium  and  Its  Preparations. — Assay  processes  for  these 
substances  have  been  recommended  on  various  occasions.  We  be- 
Heve,  how^ever,  that  such  a  process  is  only  of  relative  value  as  long 
as  the  proportion  of  the  active  substance  to  the  inactive  is  not 
known  in  the  residue  determined  as  total  alkaloids.  Quite  recently 
a  good  deal  of  light  has  been  thrown  on  the  constituents  of  gelse- 
mium and  possibly  in  the  near  future  an  assay  process  based  on  the 
estimation  of  the  active  principle  alone  will  be  worked  out. 
Glandulce  Suprarenales  et  Thyroidece. — Colorimetric  or  chemical 
estimation  of  the  active  principles  is  desirable. 
Granatum. — The  total  alkaloids  in  pomegranate  bark  can  easily 
be  estimated. 
Guar  ana  and  Its  Preparations. — The  assay  processes  are  good. 
Hydrastis  and  Its  Preparations. — The  amount  of  golden  seal 
taken  for  the  assay  is  entirely  too  large  considering  the  high  percen- 
tage of  hydrastine  in  the  drug.  There  is  no  reason  why  the  assay 
of  the  fluidextract  should  not  be  based  on  the  same  principle  as  the 
assay  of  the  drug. 
Hyoscyamus  and  Its  Preparations, — All  that  is  said  about  Bella- 
donna applies  to  these  products  also. 
Ipecacuanha  and  Its  Preparations. — The  amount  of  drug  pre- 
scribed for  the  assay  process  should  be  reduced  considerably,  say 
to  about  6  grams.  The  assay  process  otherwise  is  satisfactory. 
We  have  pointed  out  above  that  the  titration  of  the  alkaloidal  residue 
is  somewhat  difficult,  and  it  would  be  desirable  to  try  other  indicators 
which  might  prove  to  be  more  satisfactory. 
lalap. — A  shorter  process  depending  on  the  exhaustion  of  the 
root  with  hot  alcohol  and  taking,  after  cooling  and  readjusting  the 
weight,  an  aliquot  part  has  been  recommended  by  us  on  a  former 
occasion.  In  connection  with  this  drug  it  may  be  said  that  the 
quality  of  the  various  samples  and  shipments  during  the  last  twelve 
months  was  superior  to  that  in  previous  years.  Would  it  not 
be  advisable  to  control  the  galenical  preparations  of  jalap  by  simple 
assay  processes? 
Kola  and  Its  Preparations. — These  should  be  assayed  by  a 
process  similar  to  that  given  for  guarana.  To  estimate  the  amount 
of  theobromine,  acid  instead  of  water  has  to  be  used  for  extracting 
the  alkaloids  from  the  chloroformic  solution. 
Maltum  and  Extractum  Malti. — It  is  advisable  to  give  assay 
