"""Alr.s;'"""-}  Varieties.  371 
Impure  Sodium  Phosphate. — A.  B.  Lyons,  M.  D.,  writes:  "I  have  recently 
met  with  a  specimen  of  phosphate  of  sodium  bearing  the  label  of  a  reputable  Amer- 
ican manufacturing  house,  containing  a  large  percentage  of  sulphate  of  sodium.  The 
salt  had  a  suspicious  appearance  at  first  sight,  being  imperfectly  granulated,  as  if 
obtained  by  simply  evaporating  the  mother  liquor  to  dryness.  It  dissolved  com- 
pletely in  twelve  times  its  weight  of  cold  water,  whereas  pure  crystallized  sodium 
phosphate  requires  at  least  sixteen  times  its  weight.  Exposed  to  a  moderate  heat 
till  it  ceased  to  lose  weight  it  gave  up  barely  25  per  cent,  of  its  weight  of  water  of 
crystallization,  whereas  sodium  phosphate  contains  60  per  cent.  On  ignition  there 
was  a  further  loss  of  weight  amounting  to  about  2  per  cent.  5  anhydrous  sodium 
(hydro-disodic)  phosphate  would  lose  more  than  twice  that  quantity  of  basic  water. 
A  solution  of  the  salt  in  water  yielded,  after  the  addition  of  hydrochloric  acid, 
an  abundant  precipitate  with  barium  chloride.  By  a  rough  volumetric  estimation, 
the  amount  of  sulphuric  acid  (HsSO^)  was  found  to  be  about  27  per  cent,  of  the 
entire  weight  of  the  salt.  The  salt,  therefore,  deprived  of  what  remains  of  its  water 
of  crystallization,  contains  more  than  half  its  weight  of  sodium  sulphate. — Detroit 
Re'v,  of  Med.  and  Pharm.,  July. 
Determination  of  Albumen  by  Tannin. — The  determination  of  albumen 
by  a  standard  solution  of  tannin  does  not  give  correct  results,  since  all  kinds  of 
albumen  do  not  combine  with  the  same  proportion  of  the  reagent.  Thus,  that 
found  in  Bright's  disease  retains  37  per  cent,  of  tannin,  but  that  met  with  in  acci- 
dental cases  of  albuminuria,  only  28.  To  determine  albumen  by  means  of  tannin, 
it  is  necessary  to  add  to  the  albuminous  liquid,  half  its  volume  of  a  solution  con- 
taining 26  per  cent,  of  common  salt.  Solution  of  tannin  is  added  till  all  the  albu- 
men is  thrown  down.  The  whole  is  filtered,  washed  with  water  till  free  from  salt, 
the  tannin  removed  by  means  of  boiling  alcohol,  and  the  residue  dried  and  weighed. 
— Chem.  Neivs,  March  25,  from  Bull.  Soc.  Chim.,  Paris. 
Rapid  Process  for  the  Detection  of  Lead  in  the  Tin  Lining  of  Vessels. 
M.  Fordos. — Place,  with  a  tube  plunged  in  pure  nitric  acid,  a  slight  layer  of  acid  upon 
any  part  of  the  tinning,  selecting  by  preference  the  thickest  parts.  Both  metals  are 
attacked,  forming  stannic  oxide  and  nitrate  of  lead.  After  a  few  minutes,  heat 
slightly  to  expel  the  last  traces  of  acid,  and  allow  to  cool  j  then  touch  the  pulver- 
ulent spot  produced  by  the  acid  with  a  tube  dipped  in  a  solution  of  5  parts  of  iodide 
of  potassium  in  100  of  water.  The  iodide  has  no  action  upon  the  oxide  of  tin,  but 
with  the  nitrate  of  lead  it  reacts,  forming  yellow  iodide  of  lead,  and  showing  the 
presence  of  even  a  small  quantity  of  this  metal.  The  surface  of  the  tinning  must 
be  carefully  cleansed  before  applying  the  nitric  acid,  and  the  acid  should  not  pene- 
trate to  the  iron  or  copper  which  forms  the  body  of  the  vessel,  as  the  reaction  might 
thus  be  complicated. — Chem.  News  [Lond.]y  April  30,  1875,  from  Compt.  Rend. 
Decolorizing  Property  of  Ozone.  M.  A.  Boillot. — One  of  the  most  strik- 
ing properties  of  ozone  is  its  bleaching  power,  The  effects  ascribed  to  chlorine  are 
really  due  to  ozone.  Ozone  employed  directly  acts  as  an  oxidizing  agent,  laying 
hold  of  the  hydrogen  of  the  substance  with  which  it  is  in  contact,  whence  results 
