X0202 4 2007-10-22 0000073124 NORTHERN TRUST CORP NTRS 0001378549 Potter Stephen N 50 S. LA SALLE ST. CHICAGO IL 60603 0 1 0 0 Executive Vice President Common Stock 2007-10-22 4 S 0 100 68.02 D 36295 I By Trust Common Stock 2007-10-22 4 S 0 100 68.03 D 36195 I By Trust Common Stock 2007-10-22 4 S 0 100 68.04 D 36095 I By Trust Common Stock 2007-10-22 4 S 0 196 68.09 D 35899 I By Trust Common Stock 2007-10-22 4 S 0 500 68.10 D 35399 I By Trust Common Stock 2007-10-22 4 S 0 100 68.14 D 35299 I By Trust Common Stock 2007-10-22 4 S 0 104 68.15 D 35195 I By Trust Common Stock 2007-10-22 4 S 0 100 68.24 D 35095 I By Trust Common Stock 2007-10-22 4 S 0 300 68.27 D 34795 I By Trust Common Stock 2007-10-22 4 S 0 200 68.30 D 34595 I By Trust Common Stock 2007-10-22 4 S 0 500 68.325 D 34095 I By Trust Common Stock 2007-10-22 4 S 0 100 68.36 D 33995 I By Trust Common Stock 2007-10-22 4 S 0 300 68.45 D 33695 I By Trust Common Stock 2007-10-22 4 S 0 700 68.60 D 32995 I By Trust Common Stock 2007-10-22 4 S 0 200 68.63 D 32795 I By Trust Common Stock 2007-10-22 4 S 0 200 68.64 D 32595 I By Trust Common Stock 2007-10-22 4 S 0 200 68.68 D 32395 I By Trust Common Stock 2007-10-22 4 S 0 975 68.70 D 31420 I By Trust Common Stock 2007-10-22 4 S 0 100 68.75 D 31320 I By Trust Common Stock 2007-10-22 4 S 0 200 68.77 D 31120 I By Trust Common Stock 2007-10-22 4 S 0 100 68.79 D 31020 I By Trust Common Stock 2007-10-22 4 S 0 1417 68.80 D 29603 I By Trust Common Stock 2007-10-22 4 S 0 100 68.81 D 29503 I By Trust Common Stock 2007-10-22 4 S 0 42 68.82 D 29461 I By Trust Common Stock 2007-10-22 4 S 0 1236 68.90 D 28225 I By Trust Common Stock 2007-10-22 4 S 0 900 68.92 D 27325 I By Trust Common Stock 2007-10-22 4 S 0 225 68.93 D 27100 I By Trust Common Stock 2007-10-22 4 S 0 605 68.95 D 26495 I By Trust Common Stock 2007-10-22 4 S 0 100 68.98 D 26395 I By Trust Common Stock 880 I Spouse as Trustee for Son This Form 4 is being filed as Part 1 and is continued on Part 2 (due to the thirty row maximum allowed on Table I) Paul A. Bernacki Attorney-in-Fact for Stephen N. Potter 2007-10-24