The  official  salt  is  soluble  in  an  equai  weight  of  waterto  produce  a
neutral  solution.  It  is  not  soluble, in  alcohol,  With  the  sulphates  of
potassium  and  sodium,  it  gives  double  salts.  Manganous  sulphate
finds  a  limited  use  in  medicine.
Manganic  Sulphate,  MngCSOJg,  is  a  dark-green,  deliquescent  powder
which  results  from  the  action  of  concentrated  sulphuric  acid  on  man-
ganese sesquioxide  or  on  the  dioxide  at  from  100°  to  140®.
Manganese  alums  crystallize  in  octohedra,  and  arise  from  the  union
of  the  alkali  sulphates  with  manganic  sulphate.
Mangafious  Nitrate,  Mn(N03)2.6H.^O,  separates  in  deliquescent  crystals
when  manganese  carbonate  is  added  to  nitric  acid  and  the  solution  is
evaporated.  ;

Mangaftous  Phosphate,  Mn3(PO^)2.7H20,  is  produced  as  a  white
precipitate  by  the  addition  of  sodium  phosphate  to  a  solution  of  man-
ganous sulphate.
^angaftous  Hjipophosphite,  Mn(PH^OJ^+  H^O  (Mangani  Hypophos-

phis,  U.S. P.,  8th  Rev.j,  is  a  pink,  crystalline  powder,  odorless,  nearly
tasteless;  permanent  in  thle  air.  It  is  solubt(ff^  ill  S'.^^parts  of  water  at
25®C.;  almost  insoluble  in  alcohol.
Manganese  Borate  is  formed  when  a  solution  of  a  manganous  salt  is
precipitated  by  sodium  borate.  The  white  precipitate  thrown  down
becomes  brownish  upon  drying.
Manganous  Carbonate,  MnCO.^. — Manganese-spar,  the  native  form  of
this  compound,  occurs  in  red,  hexagonal  crystals,  which  are  contami-
nated with  iron  and  other  carbonates.  The  artificial  white  salt  is  pre-
pared by  adding  a  slight  excess  of  sodium  carbonate  to  a  solution  of
manganous  sulphate.  Upon  drying  it  undergoes  some  decomposition
and  becomes  darker  on  account  of  the  sesquioxide  formed.  When
ignited  it  loses  carbon  dioxide  and  leaves  manganoso-manganic  oxide.
MOLYBDENUM,  TUNGSTEN,  URANIUM.
In  addition  to  chromium  and  manganese,  in  the  foregoing  group  we  have  the
rarer  elements  molybdenum,  tungsten,  ynd  uranium.
