NOMENCLATURE  OF  SALTS 
215 
In  judging  of  the  comparative  merits  of  the  nomenclature 
of  salts  on  the  neutrality  principle,  and  on  the  equivalent-com- 
position principle,  the  question  of  the  propriety  or  non-propriety 
of  prefixes  relating  to  the  base,  is  not  necessarily  involved;  but, 
as  the  writer,  on  whose  remarks  this  note  is  a  comment,  is  willing 
to  use  such  prefixes,  they  will  be  employed  in  expressing  the 
nomenclature  he  advocates,  in  the  comparative  view  given  below. 
Two  sulphates  of  iron  (FeO,S03,  and  Fe203,3S03).  The 
names  of  these  salts  on  the  neutrality  principle  are  protosulphate 
of  iron  and  sesquisulphate  of  iron  ;  on  the  equivalent-composition 
principle,  monosulphate  of  protoxide  of  iron  and  tersulphate  of 
sesquioxide  of  iron.  In  the  two  names,  here  objected  to,  the 
word  «  sulphate  "  means,  first,  one  equivalent  of  sulphuric  acid, 
and,  afterwards,  three  equivalents  of  sulphuric  acid.  The  adept, 
it  is  true,  can  analyze  the  name,  "  sesquisulphate  of  iron."  He 
may  say,  "  sesqui "  means  that  there  are  three  equivalents  of 
oxygen  in  the  base,  united  with  two  of  iron  ;  and  for  each  of 
these  equivalents  of  oxygen,  there  must  be  one  equivalent  of 
acid,  that  is,  three  equivalents  altogether.  In  the  other  name 
for  the  same  salt,  the  prefix,  ter,  relates  to  the  acid,  and  de- 
notes that  three  equivalents  of  acid  are  present,  without  de- 
pending on  a  correct  inference  being  drawn  that  three  are 
present,  from  knowing  the  stage  of  oxidation  of  the  metal. 
The  prefix,  mono,  given  above,  is  not  strictly  necessary ;  but 
it  is  better  to  use  it,  when,  as  in  this  case,  two  salts  of  the 
same  metal  are  in  question,  containing,  severally,  one  equiva- 
lent and  more  than  one  equivalent  of  the  same  acid.  In  ex- 
pressing nitre  (KO,N05),  there  would  be  no  motive  for  saying 
mononitrate  of  potassa  ;  because  no  higher  nitrate  of  this  alkali 
is  known. 
Salt  having  the  formula,  Fe203,3N05.  The  name  of  this  salt 
on  the  neutrality  principle  is  sesquinitrate  of  iron  ;  on  the  equiv- 
alent-composition principle,  ternitrate  of  sesquioxide  of  iron. 
Salt  having  the  formula,  Hg02,2S03.*  The  name  of  this  salt 
on  the  neutrality  principle  is  deutosulphate  of  mercury  ;  on- the 
equivalent-composition  principle,  bisulphate  of  deutoxide  of 
mercury.    The  salt  having  the  formula,  Hg02,4S03,  if  it  existed, 
*  The  old  number  for  the  equivalent  of  mercury  is  here  assumed,  and  not 
the  old  number  divided  by  two. 
