AmMa"r'x8P76?rm'}      Basicity  of  the  Phosphorus  Acids.  1 1 1 
of  their  hydrogen  is  not  replaceable,  and  that  only  that  portion  is  typic 
which  is  liberated,  by  means  of  heat,  in  combination  with  oxygen.  In 
the  orthophosphoric  acid,  the  accretion  of  oxygen  has  so  far  progressed 
that  the  direct  contact  between  phosphorus  and  hydrogen  is  no  longer 
maintained,  since  the  balance  of  affinity  now  leans  strongly  towards 
the  oxygen.  Heat  now  expels  hydrogen  only  in  combination  with 
oxygen,  but  no  amount  of  heat  can  expel  more  than  two-thirds  of  all 
the  hydrogen  combined.  The  remaining  third,  constituting  the  typic 
hydrogen  of  metaphosphoric  acid  is  absolutely  beyond  the  direct  influ- 
ence of  phosphorus,  and  the  powerful  affinity  of  phosphorus  for  oxy- 
gen, on  the  one  side,  and  oxygen  for  hydrogen  on  the  other,  retains 
the  compactness  of  the  union  beyond  the  ordinary  effects  of  molecular 
vibration. 
By  this  arrangement  we  also  discover  the  appalling  inconsistency 
of  the  new  notation  in  its  treatment  of  the  phosphoric  acids.  The 
misconception  of  the  tetrabasicity  of  pyrophosphoric  acid,  and  the  erro- 
neous theory  of  the  trivalent  radical  phosphoryl,  (PO)r//,  together  with 
the  entire  new  notation  of  the  phosphoric  acids,  are  thereby  wholly 
refuted.  Trivalent  phosphoryl  is  utterly  inapplicable  in  case  of  pyro- 
phosphoric and  metaphosphoric  acids,  as  no  satisfactory  expression  can 
be  obtained  by  its  use.  It  is  also  plain  that  a  trivalent  radical  cannot 
be  common  to  a  monobasic,  a  tribasic  and  a  tetrabasic  acid.  Further- 
more, the  inconsistency  of  the  notation  must  refute  itself  which  rep- 
resents the  three  acids  thus  : 
Metaphosphoric  acid,  P03H=P02(OH). 
Orthophosphoric  acid,  P04H3=P0(0H)3. 
Pyrophosphoric  acid,  P207H4=P203(OH)4. 
Which  indicates  that  there  are  as  many  independent  radicals  as  acids, 
and  that  while  (P02)'  is  univalent,  (PO)'"  is  trivalent  and  (P2Os)iv quad- 
rivalent. There  is  neither  sense  or  reason  in  such  an  assumption  in 
view  of  the  fact  that  the  three  acids  differ  from  one  another  by  two 
equivalents  of  hydroxyl  less  for  every  equivalent  of  oxygen  in  excess 
of  the  radical,  P202,  as  is  shown  by  the  following  : 
Metaphosphoric  acid,  P204(OH)2=P202(OH)202. 
Pyrophosphoric  acid,  P203(OH)4=P202(OH)40. 
Orthophosphoric  acid,  P202(OH)6=P202(OH)6. 
According  to  the  new  notation  of  the  phosphoric  acids,  metaphos- 
phoric acid,  (P03H),  is  first,  orthophosphoric  acid,  (P04H3),  second, 
