Jour.  Pharm, ) 
July,  1898.  ; 
Assay  of  Vallefs  Mass. 
343 
MILK  SUGAR. 
One  of  the  tests  for  the  purity  of  milk  sugar,  according  to  the 
U.S.P.,  1890,  requires  that  no  brownish  or  blackish  color  shall 
develop  within  thirty  minutes  when  the  milk  sugar  is  sprinkled 
over  the  surface  of  sulphuric  acid. 
Occasionally  a  sample  is  found  which  does  not  test  as  good  in 
this  respect  and  yet  polarizes  equally  as  well  as  a  sample  which 
does  not  show  any  coloration.  Some  crystallized  milk  sugar  was 
obtained  and  the  suggestion  offered  itself  that  the  presence  of  thread 
or  string  upon  which  the  crystals  are  allowed  to  form  (as  in  the  case 
of  rock  candy)  might  be  responsible  for  some  coloration. 
Investigation  showed  this  to  be  the  case ;  clean  crystals  from  the 
outer  side  of  the  string  gave  no  coloration  after  being  powdered  and 
tested  according  to  the  U.S. P.  directions,  while,  in  the  case  of  the 
section  across  the  entire  string,  the  coloration  was  directly  propor- 
tional to  the  thickness  of  the  crystalline  mass,  or,  in  other  words, 
to  the  quantity  of  thread  which  had  been  powdered  up  with  the 
milk  sugar. 
Polarization  is  the  safest  test,  as  it  can  be  seen  that  a  good  milk 
sugar  might  be  unjustly  rejected  under  the  above  conditions. 
Perhaps  manufacturers  of  this  article  might  substitute  some  fiber 
less  carbonizable  than  that  now  used,  if  attention  were  called  to  it. 
301  Cherry  Street. 
ASSAY  OF  VALLET'S  MASS. 
By  Henry  K.  Thompson,  P.C. 
Contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of 
Pharmacy.    No.  177. 
The  usefulness  of  the  official  formula  for  Vallet's  mass  depends 
upon  the  formation  and  preservation  of  ferrous  carbonate,  which  is 
insoluble  in  water,  and  free  from  irritating  and  styptic  properties. 
The  author  has  made  some  experiments  with  the  view  to  devising 
a  method  by  which  the  pharmacist  can  conveniently  and  with  fair 
accuracy  ascertain  the  amount  of  ferrous  carbonate  which  Vallet's 
mass,  of  his  own  or  other  manufacture,  may  contain. 
After  several  unsuccessful  attempts  to  find  shorter  processes,  the 
following  method  of  assay  was  considered  satisfactory  for  the  pur- 
