^p/cT/mr*"  }    Bromine  m  Analytical  Chemistry.  557 
Take  of  Normal  plumbic  acetate  (cryst.),  32  troy  ounces. 
Potassium  hydrate  (pure)  4f  troy  ounces. 
Distilled  water  sufficient. 
Dissolve  16  troy  ounces  of  the  lead  salt  in  3  pints  of  distilled  water, 
with  heat.  Dissolve  the  potassium  hydrate  in  8  fluid  ounces  of  dis- 
tilled water,  and  mix  the  solutions  ;  continue  the  heat  a  short  time 
longer,  and  when  nearly  cooled,  pour  the  magma  on  to  a  muslin 
strainer,  and  wring  the  liquid  out  with  thorough  pressure.  Dissolve 
the  remaining  16  troy  ounces  of  the  lead  salt  in  3J  pints  of  distilled 
water  with  heat ;  to  the  solution  add  the  magma  of  plumbic  hydrate, 
and  continue  the  heat  until  this  has  dissolved.  Now  add  distilled 
water  to  the  measure  of  4J  pints.  Mix  and  filter. —  The  Pharmacist, 
Oct,  1871. 
ON  THE  EMPLOYMENT  OF  BROMINE  IN  ANALYTICAL 
CHEMISTRY. 
By  p.  Waage. 
Translated  by  P.  Schweizer,  Ph.  D.,  from  Fresemus'  Zeitschrtft,  for  1871, 
second  quarterly  number. 
The  oxidizing  agents,  which  are  principally  employed  to-day  in 
chemical  analysis,  are  nitric  acid,  chlorate  of  potassa  and  hydro- 
chloric acid,  and  chlorine.  Each  of  these,  however,  though  excellent 
in  some  ways,  has  drawbacks  to  its  general  employment. 
Among  those,  prominent  in  the  use  of  nitric  acid,  is  the  slowness 
with  which  it  acts  in  dilute  solutions  ;  the  length  of  time  required, 
even  when  concentrated,  to  oxidize  sulphur;  that  it  never  can  be  em- 
ployed in  platinum  vessels,  on  account  of  small  quantities  of  chlorine, 
which  it  generally  contains,  and  that  it  must  never  come  in  contact 
with  organic  matter,  like  filter  paper,  if  a  subsequent  precipitation  of 
a  metallic  oxide  is  desired. 
Chlorate  of  potassa  acts  only  in  the  presence  of  somewhat  concen- 
trated hydrochloric  acid,  which,  in  larger  quantities  may,  under  certain 
conditions,  afiect  the  accuracy  of  the  work.  Considerable  difficulty  is 
at  the  same  time  experienced  in  driving  out  the  last  traces  of  chlorine 
by  boiling,  especially  in  working  with  dilute  solutions.  Undecom- 
posed  chlorate  of  potassa  is  generally  the  cause  of  this  difficulty,  and 
addition  of  more  hydrochloric  acid  will  be  necessary,  which  requires 
subsequent  dilution  before  filtration. 
The  limit  for  the  use  of  chlorine  water  is  a  narrow  one,  as  it  does 
