266  MERCURY — ITS  OXIDES  AND  ACETATES,  ETC. 
Acetate  of  Mercuric  Oxide  "  is  soluble  in  four  parts  of  water 
at  50°  F.,  and  in  2.75  parts  at  65°F."— GW. 
"  Boiled  with  sugar  it  is  converted  into  mercurous  acetate." 
—  Vogel. 
An  acid  solution  of  mercuric  acetate  is  not  affected  by  caustic 
ammonia. 
"  Not  in  any  case  is  it  affected  by  ammonia,  when  the  acid  is 
in  excess." — Cfarot. 
Ammonia  added  carefully  till  slightly  in  excess,  produces  no 
disturbance  of  the  solution. 
Caustic  potash  precipitates  the  red  oxide  from  the  acid  solu- 
tion, but  not  so  completely  that  sulphide  of  ammonium  does  not 
affect  the  filtrate.  «  If  the  solution  is  very  acid,  no  precipitate 
is  produced,  or  a  very  slight  one." — Grmelin. 
Acetic  acid  containing  a  small  amount  of  alcohol,  when  heated 
over  red  oxide  of  mercury,  forms  mercurous  acetate  with  the 
production  of  acetic  ether. 
A  solution  of  mercuric  acetate,  which  had  stood  for  several 
days,  was  found  to  afford  precipitates  with  soluble  chlorides, 
though  it  was  not  when  prepared  so  affected  ;  an  examination 
into  the  cause,  showed  the  acetic  acid  to  contain  alcohol.  Alco- 
hol was  then  added  to  a  solution  of  mercuric  acetate,  and  dis- 
tilled.   Acetic  ether  was  obtained. 
"  With  a  neutral  solution,  ammonia  gives  a  turbidity  with  one 
part  of  the  salt  in  20,000  parts  of  water." 
Hyposulphite  of  soda  gives  with  acid,  as  well  as  with  neutral 
solutions,  a  lemon  yellow  color,  changing  gradually  to  brown. 
This  reaction  is  very  characteristic  of  the  salt  of  the  red  oxide, 
and  is  quite  marked  in  a  solution  containing  1  part  of  the  salt 
in  6,000  parts  of  water.  The  presence  of  chloride  of  sodium, 
or  chloride  of  ammonium,  when  the  solution  is  very  dilute,  en- 
tirely prevents  the  reaction. 
As  a  Summary  of  the  Investigation,  we  have  the  following : — 
1st.  Mercury,  when  pure,  is  not  affected  by  any  exposure  to 
which  it  is  liable.  In  a  state  of  minute  division  it  is  not  acted 
on  by  boiling  glacial  acetic  acid,  and  yields  nothing  to  coll  mu- 
riatic acid;  when  highly  diluted. 
2d.  Black  oxide  of  mercury  is  soluble  to  a  very  appreciable 
extent  in  hot  water,  the  solution,  when  cold,  still  retaining  a 
