568       Recent  Literature  Relating  to  Pharmacy.  {^vim^^ST 
Gm.  and  water  to  250  cc.)  and  shake  well,  on  comparing  the  tint  ob- 
tained with  the  standard  tints  (made  from  known  material)  the  per- 
centage of  adulteration  can  be  ascertained  within  5  per  cent.  A 
method  for  making  more  exact  determinations  is  also  given. 
L.  F.  K. 
QUANTITATIVE  ESTIMATION  OF  FORMALDEHYDE. 
After  experimentation  with  all  suggested  methods  of  formalde- 
hyde assay,  Utz  {pilddtsch.  Ap.  Zt.,  1901,  147)  reports  the  following 
as  satisfactory:  henberg's  method,  in  which  the  sample  is  treated 
with  an  aqueous  solution  of  diphenylen-dihydrazin  hydrochlorate, 
and  from  the  weight  of  the  washed  and  dried  crystals  of  composition, 
C6H4HN  —  N  =  CH2 
II 
C6H4HN  —  N  =  CH 
the  quantity  of  formalin  is  deduced.  This  method  gives  best  results 
in  a  1  to  1,000  solution. 
Clowe's  process,  in  which  the  formaldehyde  is  condensed  with 
phloroglucin,  4*6  parts  of  the  dried  solid  representing  1  part  of  the 
aldehyde. 
Both  these  gravimetric  processes  prove  tedious,  hence  a  volu- 
metric process  is  preferable,  and  of  these  the  writer  prefers  the 
Romijn  and  the  ammonia  processes.  In  Romijn's  the  liquid  is 
treated  with  the  decinormal  iodine  and  then  with  strong  soda  solu- 
tion to  a  bright  yellow  tint.  After  ten  minutes  hydrochloric  acid 
is  added  until  the  liquid  is  brown  and  the  free  iodine  is  titrated  with 
decinormal  thiosulphate.  Two  atoms  iodine  equals  1  molecule 
formaldehyde. 
The  ammonia  process,  discussed  by  Kebler  (see  this  Journal,  1898, 
432),  has  been  adopted  by  the  German  pharmacopoeia.  Utz 
denies  the  inaccuracy  of  the  process  complained  of  by  Kebler, 
claiming  good  results  by  allowing  the  mixture  of  ammonia  and 
formalin  to  stand  an  hour.  H.  V.  A. 
LOCATION  OF  ALKALOID  IN  VERATRUM  ALBUM. 
By  microchemical  alkaloidal  reagents,  viz.,  phosphotungstic  acid 
or  ammonium  molybdate,  the  active  ingredients  of  Veratrum  album 
were  sought  for  in  the  tissues  of  the  plant,  and  were  found  practi- 
