ACTION  OF  WATER  ON  CHLORIDE  OF  LIME,  <fcC.  261 
drate  of  lime ;  or  a  combination  of  hypochlorite  of  lime  with 
chloride  of  calcium,  mixed  with  hydrate  of  lime.  M.  Millon,  on 
the  contrary,  considers  it  to  have  the  composition  CaO,Cl.  The 
author  thought  that  the  action  of  water  on  chloride  of  lime 
would  throw  some  light  on  its  constitution. 
The  chloride  of  lime  employed  for  analysis  was  taken  from  a 
large  sample  of  250  kilogrammes.  It  yielded  26-52  p.  c.  of 
chlorine,  and  13-25  p.c.  of  hypochlorous  acid.  To  estimate  the 
whole  of  the  chlorine  a  weighed  quantity  was  treated  with  water 
and  ammonia,  nitric  acid  added,  and  the  solution  then  neutral- 
ized by  carbonate  of  soda.  The  chlorides  were  then  estimated 
in  the  liquid  by  nitrate  of  silver.  By  the  volumetric  process 
with  bichromate  of  potash,  29-57  p.  c.  of  chlorine  was  found. 
The  lime  was  precipitated  by  oxalate  of  ammonia.  Two 
analyses  yielded  46-35  p.  c.  and  46-40  p.  c.  Mean  =46-37  p.  c. 
From  these  numbers  the  following  composition  is  calculated:— 
CaO,C10    ....  26-72 
CaCl  25-51 
CaO  23-05 
Water  24-72 
100-00 
Which  may  be  thus  stated  : — 
CaO,C10                                                        .  26-72 
CaCl  (in  combination  with  the  above  as  CaO,C10-f  CaCl)  20-72 
CaCl  in  excess   4-79 
CaO,HO   3046 
Water  combined  .......  17-31 
100-00 
The  author  has  verified  this  composition  in  the  following 
manner : — 
A  weighed  portion  of  chloride  of  lime  was  treated  with  a 
known  volume  of  hydrochloric  acid.  The  reaction  was  conduct- 
ed in  a  flask  furnished  with  a  long  glass  tube  to  avoid  loss  of 
the  acid.  The  difference  in  strength  of  the  hydrochloric  acid 
before  and  after  the  experiment  showed  the  quantity  of  acid 
saturated  by  the  lime.  This  was  found  to  be  equivalent  to 
57-206  of  anhydrous  acid  for  100  of  the  chloride.    This  closely 
