OHJGAXioinL  537

eren  to  pick  out  "what  is  due  him ;  but  it  is  good  if  he  is
allowed  to  keep  the  whole.  A  tender  of  money  most  be  of  ^oi^Jf"^*'
legal  tender  money ;  but  if  anything  which  is  commonly  accepted
as  money  is  tendered,  such  as  a  dieck  or  bank  IhUs,  it  is
good  unless  specially  objected  to  on  the  ground  of  its  not
being  legal  tender.  What  kind  of  money  is  legal  tender  is
determined  by  statute,  in  the  United  States  by  national
statutes.
773.  If  a.  debtor  owes  two  or  more  debts  to  the  same  ii^„P^'J'*I|^".
creditor  all  of  which  are  due  and  payable,  and  pays  him  a  "®°^
sum  of  money  not  sufficient  to  discharge  them  all,  the  debtor
may  appropriate  the  payment  to  whichever  of  the  debts  he
pleases.  K  he  does  not  do  so,  the  creditor  has  the  right  to
appropriate,  and  may  even  apply  the  money  to  a  debt  which
has  been  barred  by  the  statute  of  limitations  ^  and  thus  reduced
to  the  condition  of  an  imperfect  obligation.  If  neither  ptvrty
makes  any  appropriation,  the  law  will  appropriate  the  payment,
generally  to  the  oldest  debt.
774»    If    an     obligation     was    valid    at    its  inception    but  rwrfonnnncc
performance  afterwards  becomes  unlawful,  the   obligation    is   di»-
chanced.      K  the    act   to   be   done   is   from   the   first  impossible  impoMibiiity

*-*  *  of  perform-

of  performance,  no  obligation  ever  arises.      A  contract  to   do   an       »»cc.
impossible    act    is   void.      But   if    it    becomes    impossible    after-
wards, the  rule  is  that  if   the  law   casts   a   duty    upon    a    man,  Dnt*®'^^*'":

'  .^         r^  '  ed  by  Iaw  and

and  he  is  disabled  from  performing  it  without  his  fault,  the  »>y  contract.
