COBALT.
Sp.  11.  Acetite  of  Cobalt.
ACEToUS  ACID  dissolves  the  oxide  of  cobalt  with  facility. ¬
  The  solution  does  not  crystallize  ;  and  when
evaporated  to  dryness,  soon  deliquesces  again.  It  has
a  fine  red  colour  while  cold,  but  becomes  blue  when
heated  *.
Sp.  12.  Oxalat  of  Cobalt.
OXALIC  AcID  attacks  cobalt,  and  converts  it  into  a
red  powder,  which  is  oxalat  of  cobalt.  This  salt  is  insoluble ¬
  in  water,  but  it  dissolves  in  an  excess  of  acid,
and  yields  crystals.  Oxalic  acid  precipitates  an  oxalat
of  cobalt  from  thé  solution  of  that  metal  in  most  acids ¬
  f.
The  remaining  salts  of  cobalt  have  not  hitherto  been
examined.
GENUS  XVI.  SALTS  OF  MANGANESE.
ALL  the  properties  of  this  genus  of  salts  with  which
we  are  even  at  present  acquainted  were  ascertained  by
Bergman  and  Scheele,  by  whose  labours  the  oxide  of
manganese,  one  of  the  most  important  of  all  their  instruments, ¬
  was  first  put  into  the  hands  of  chemists.
The  salts  of  manganese  may  be  distinguished  by  the  following ¬
  properties  :
1.  They  are  almost  all  soluble  in  water  ;  and  the  so-  Characters.
lution,  when  treated  with  fixed  alkalies,  deposites  a
white  or  reddish  coloured  precipitate,  which  very  soon
becomes  black  when  exposed  to  the  air.
*  Wenzel's  Verwand.  p.  194.
t  Bergman,  i.  270.
F2

Chap.  III.