In  Toledo,  etc.,  R.  Co.  v.  Pennsylvania  R.  Co.,  54  Fed.  Rep.  746.  756,  it  is
said  by  Rider,  J.  :  *'An  act,  when  done  by  an  individual  in  the  exercise  of  a
right,  may  be  lawful,  but  when  done  by  a  number  conspiring  to  injure  or  im-
properly influence  another  may  be  unlawful."


United  States  v.  Trans-Missouri  Freight  Association,  bt  au

(Circuit  Court  of  Appeals,  Eighth  Circuit.    October  2, 1893.)

1.  Railroaj>  companies.  Combinations  to  regulate  rates  and  fob
other  purposes.  principles  of  construction  to  be  applied  to  the
FEDERAL  ANTI-TRUST  LAW.  In  construihg  the  act  of  Congress  of  July  3,
1890,  entitled  "  An  act  to  protect  trade  and  commerce  agains  unlawful  re-
straints and  monopolies,"  three  well  settled  rules  must  be  applied  to  ascertain
the  meaning  and  scope  of  the  act :  (1).  It  must  be  read  in  the  light  of  all  gen-
eral laws  upon  the  same  subject  in  force  at  the  time  of  the  passage  of  the  act ;
(2).  When  words  have  acquired  a  well  understood  meaning  by  judicial  interpre-
tation, it  is  to  be  presumed  that  they  are  used  in  that  sense  in  a  subsequent
statute,  unless  the  contrary  clearly  appears  ;  (8).  Where  Congress  creates  an
offense,  and  uses  common -law  terms,  the  courts  may  properly  look  to  that
body  of  Jurisprudence  for  the  true  meaning  of  tlie  terms  used,  and,  if  it  is  a
common-law  offense,  for  the  definition  of  the  offense  if  it  is  not  clearly  defined
in  the  act  adopting  or  creating  it.
