260         ACTION  OF  WATER  ON  CHLORIDE  OP  LIME,  &G. 
the  metallic  lead  was  calculated  as  before :  the  sulphate  of  tin 
was  then  calcined  to  convert  it  into  binoxide,  from  which  the 
metallic  tin  was  calculated.  There  appears  to  be  no  objection 
to  this  process,  except  that  it  is  rather  long,  as  it  gives  very 
good  and  accurate  results  ;  it  has,  moreover,  the  merit  of  simpli- 
city. The  annexed  table  gives  at  A  the  results  of  the  second 
process  upon  sample  No,  1  ;  and  at  B  the  results  of  the  third 
process  upon  the  same  sample  : — 
A.  B. 
Lead    85-52  Lead  84-84 
Tin      14.12  Tin  15-06 
99-64  99-90 
Both  these,  it  will  be  observed,  estimate  the  lead  a  little  too 
low,  arising  from  insufficiency  of  washing,  some  time  being  re- 
quired to  complete  that  part  of  the  process. 
The  process,  however,  which  1  found  to  give  me  by  far  the 
best  results,  and  to  be  the  most  convenient  in  execution,  is  one 
described  by  Rose.  It  consists  in  fusing  the  alloy  with  an  ex- 
cess of  a  mixture  of  sulphur  and  carbonate  of  soda.  The  metals 
combine  with  the  sulphur  to  form  sulphides,  while  at  the  same 
time  the  sulphur  and  carbonate  of  soda  react  to  form  sulphide  of 
sodium.  The  sulphide  of  tin  combines  with  the  alkaline  sulphide, 
forming  a  soluble  compound,  while  the  sulphide  of  lead  remains 
unaffected.  The  fused  mass  is  digested  with  water,  and  filtered. 
The  insoluble  sulphide  of  lead  is  washed,  dried,  and  calcined 
with  a  mixture  of  nitric  and  sulphuric  acids,  whereby  it  is  con- 
verted into  sulphate,  from  which  the  lead  is  calculated  as  in  the 
previous  cases ;  to  the  filtrate  excess  of  hydrochloric  acid  is  ad- 
ded, which  decomposes  the  sulphur  compounds,  and  precipitates 
sulphur  and  the  sulphide  of  tin  ;  the  precipitate  is  washed,  dried, 
treated  with  nitric  acid,  and  calcined,  when  binoxide  of  tin  re- 
sults, from  which  the  metal  is  calculated. — Lon.  Pharm.  Jour. 
Jan.  1862. 
ACTION  OF  WATER  ON  COMMERCIAL  CHLORIDE  OF  LIME, 
AND  REMARKS  ON  ITS  CHEMICAL  CONSTITUTION. 
By  M.  Fresenius. 
It  is  generally  admitted  that  chloride  of  lime  is  composed  of 
a  mixture  of  hypochlorite  of  lime,  chloride  of  calcium,  and  hy- 
