<PAGE>
 
                                           Registration Statement No. 333-_____

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                              __________________

                                   FORM S-8

                            REGISTRATION STATEMENT
                                     Under
                          The Securities Act of 1933

                          Northern Trust Corporation
              (Exact name of issuer as specified in its charter)

       Delaware                                           36-2723087
(State of Incorporation)                       (IRS Employer Identification No.)
               50 South LaSalle Street, Chicago, Illinois 60675

             Northern Trust Corporation Deferred Compensation Plan
                             (Full Title of Plan)

                         Peter L. Rossiter,
                         Executive Vice President and General Counsel
                         50 South LaSalle Street
                         Chicago, Illinois 60675
                         (Name and Address of Agent for Service)

                                (312) 630-6000
____________________________________________________________________________
        (Telephone number, including area codes, of agents for service)

                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
                                       Proposed      Proposed
                                       Maximum       Maximum
                        Amount         Offering      Aggregate     Amount of
Title of Securities     To Be          Price Per     Offering      Registration
to be Registered (1)    Registered     Obligation    Price (2)     Fee
<S>                     <C>            <C>           <C>           <C>

Deferred Compensation   $52,500,000       100%       $52,500,000   $15,487.50
Obligations
</TABLE>

(1)  The Deferred Compensation Obligations are unsecured obligations of Northern
     Trust Corporation to pay deferred compensation in the future in accordance
     with the terms of the Northern Trust Corporation Deferred Compensation
     Plan.

(2)  Estimated solely for the purpose of determining the registration fee.
<PAGE>
 
                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

                                        
Item 3. Incorporation of Documents by Reference.

     The following documents are incorporated herein by reference:

     (a)  The Annual Report on Form 10-K of Northern Trust Corporation (the
          "Registrant") for the fiscal year ended December 31, 1997;

     (b)  The Registrant's Quarterly Report on Form 10-Q for the quarter ended
          March 31, 1998; and

     (c)  The Registrant's Current Reports on Form 8-K filed on January 21,
          April 3, and April 21, 1998.

     All documents filed by the Registrant pursuant to Sections 13(a), 13(c),
14 and 15(d) of the Securities Exchange Act of 1934 (the "1934 Act") subsequent
to the date hereof and prior to the termination of the offering of the
securities registered pursuant to this Registration Statement shall be deemed to
be incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained in a
document incorporated or deemed to be incorporated by reference herein shall be
deemed to be modified or superseded for purposes of this Registration Statement
to the extent that a statement contained herein or in any other subsequently
filed document which also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

Item 4. Description of Securities.

     The Northern Trust Corporation Deferred Compensation Plan Obligations
("Obligations") are general unsecured obligations of the Registrant to pay
deferred compensation in the future in accordance with the terms of the Northern
Trust Corporation Deferred Compensation Plan ("Plan") from the general assets of
the Registrant, and rank pari passu with other unsecured and unsubordinated
indebtedness of the Registrant from time to time outstanding.
<PAGE>
 
     The Obligations are not subject to redemption, in whole or in part. The 
amount of compensation to be deferred by each participating employee (each a 
"Participant") will be determined in accordance with the Plan based on elections
by each Participant. Each Obligation will be payable on a date selected by each
Participant in accordance with the terms of the Plan. The Obligations will be
invested in one or more investment vehicles selected by a committee responsible
for administration of the Plan. Each Participant's Obligation will be adjusted
to reflect the investment experience, whether positive or negative, of the
selected vehicles, including any appreciation or depreciation. The Obligations
will be denominated in United States dollars.

     The Registrant reserves the right to amend or terminate the Plan at any
time, provided that no amendment or termination may directly or indirectly
reduce the balance of any Obligations as of the effective date of the amendment
or termination.

     The Obligations are not convertible into any other obligations of the
Participant.  The Obligations will not have the benefit of a negative pledge or
any other affirmative or negative covenant on the part of the Registrant.  The
Obligations are funded by means of a "rabbi trust" for which Harris Trust and 
Savings Bank, Chicago, Illinois, an independent corporate trustee has been
appointed. The trustee will not have the authority for, and each Participant
will be responsible for acting independently with respect to, among other
things, the giving of notices, responding to any requests for consents, waivers
or amendments pertaining to the Obligations, enforcing covenants and taking
further action upon a default.

Item 5. Interests of Named Experts and Counsel.

     Peter L. Rossiter, Executive Vice President and General Counsel of the 
Registrant, has furnished the opinion attached as Exhibit 5 to this registration
statement with respect to the validity of the securities being registered 
hereunder. As of May 1, 1998, Mr. Rossiter owned 130,183 shares of Common Stock 
of the Registrant, which includes 114,870 shares issuable pursuant to stock 
options.

Item 6. Indemnification of Directors and Officers.

     Section 145 of the Delaware General Corporation Law and Article Eighth of
the Corporation's Restated Certificate of Incorporation provide for
indemnification of the Corporation's directors and officers in a variety of
circumstances, which may include liabilities under the Securities Act of 1933,
as amended (the "1933 Act").  The general effect of these provisions is to
provide that the Corporation shall indemnify its directors and officers against
all liabilities and expenses reasonably incurred in connection with the defense
or settlement of any judicial or administrative proceedings in which they become
involved by reason of their status as corporate directors or officers, if they
acted in good faith and in the reasonable belief that their conduct was neither
unlawful (in the case of criminal proceedings) nor inconsistent with the best
interests of the Corporation.  With respect to legal proceedings by or in the
right of the Corporation in which a director or officer is adjudged liable for
improper performance of his duty to the Corporation, indemnification is limited
by such provisions to that amount which is permitted by the court.  In addition,
the Corporation has purchased insurance as permitted by Delaware law on behalf
of directors, officers, employees or agents, which may cover liabilities under
the 1933 Act.

                                      -2-
<PAGE>
 
Item 7. Exemption from Registration Claimed.

     Not applicable.

Item 8. Exhibits.

     The Exhibits filed herewith are set forth on the Exhibit Index filed as
part of this registration statement.

Item 9. Undertakings.

     (a) The undersigned Registrant hereby undertakes:

          (1) To file, during any period in which offers or sales are being 
     made, a post-effective amendment to this registration statement:

               (i) To include any prospectus required by Section 10(a)(3) of the
          1933 Act;

               (ii) To reflect in the prospectus any facts or events arising
          after the effective date of the registration statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the registration statement. Notwithstanding the foregoing, any
          increase or decrease in volume of securities offered (if the total
          dollar value of securities offered would not exceed that which was
          registered) and any deviation from the low or high and of the
          estimated maximum offering range may be reflected in the form of
          prospectus filed with the Commission pursuant to Rule 424(b) if, in
          the aggregate, the changes in volume and price represent no more than
          20 percent change in the maximum aggregate offering price set forth in
          the "Calculation of Registration Fee" table in the effective
          registration statement; and

               (iii) To include any material information with respect to the
          plan of distribution not previously disclosed in the registration
          statement or any material change to such information in the
          registration statement;

     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if
     the registration statement is on Form S-3, Form S-8 or Form F-3, and the
     information required to be included in a post-effective amendment by those
     paragraphs is contained in periodic reports filed with or furnished to the
     Commission by the Registrant pursuant to Section 13 or 15(d) of the 1934
     Act that are incorporated by reference in the registration statement.

                                      -3-
<PAGE>
 
          (2) That, for the purpose of determining any liability under the l933
     Act, each such post-effective amendment shall be deemed to be a new
     registration statement relating to the securities offered therein, and the
     offering of such securities at that time shall be deemed to be the initial
     bona fide offering thereof.

          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.

     (b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (c) Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the 1933 Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.

                                      -4-
<PAGE>

                                  SIGNATURES

The Registrant

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago and State of Illinois on the 14th day of May,
1998.

                                   NORTHERN TRUST CORPORATION
                                   By   /s/ Peter L. Rossiter
                                        ---------------------
                                   Peter L. Rossiter
                                   Executive Vice President and General Counsel


     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons in the
capacities indicated on the 14th day of May, 1998.


Signature                              Title

WILLIAM A. OSBORN*                     Chairman of the Board
----------------------                 President, Chief Executive
William A. Osborn                      Officer and Director


BARRY G. HASTINGS*                     President, Chief Operating
----------------------                 Officer and Director
Barry G. Hastings


PERRY R. PERO*                         Senior Executive Vice President
----------------------                 and Chief Financial Officer
Perry R. Pero


HARRY W. SHORT*                        Senior Vice President
----------------------                 and Controller
Harry W. Short


DUANE L. BURNHAM *                     Director
----------------------
Duane L. Burnham


DOLORES E. CROSS*                      Director
----------------------
Dolores E. Cross


SUSAN CROWN*                           Director
----------------------
Susan Crown

                                      -5-
<PAGE>
 
Signature                  Title



ROBERT S. HAMADA*          Director
----------------------     
Robert S. Hamada


ROBERT A. HELMAN*          Director
----------------------     
Robert A. Helman


ARTHUR L. KELLY*           Director
----------------------     
Arthur L. Kelly


FREDERICK A. KREHBIEL*     Director
----------------------     
Frederick A. Krehbiel


WILLIAM G. MITCHELL*       Director
----------------------     
William G. Mitchell


EDWARD J. MOONEY*          Director
----------------------     
Edward J. Mooney


HAROLD B. SMITH*           Director
----------------------     
Harold B. Smith


WILLIAM D. SMITHBURG*      Director
----------------------     
William D. Smithburg


BIDE L. THOMAS*            Director
----------------------     
Bide L. Thomas


     *Peter L. Rossiter, pursuant to powers of attorney duly executed by each of
the above Directors and Officers of Northern Trust Corporation and filed with
the Securities and Exchange Commission in Washington, D.C., hereby executes this
registration statement on behalf of each of the persons named above in the
capacity set forth opposite his or her name.


       /s/ Peter L. Rossiter                  May 14, 1998
       ---------------------                         
       Peter L. Rossiter
       (Attorney-in-fact)

                                      -6-
<PAGE>
 
                                 EXHIBIT INDEX
                                        
                                        

Exhibit
Number    Description                                      Page No.
------    -----------                                      --------


4.1       Restated Certificate of Incorporation
          (Incorporated by reference to Registrant's 
          Quarterly Report on Form 10-Q for the 
          quarter ended March 31, 1997)

4.2.      By-laws, as amended
          (Incorporated by reference to Registrant's 
          Quarterly Report on Form 10-Q for the 
          quarter ended March 31, 1996)

5.        Opinion of Counsel

23.1      Consent of Counsel
          (Contained in its opinion filed as Exhibit 5)
23.2      Consent of Independent Public Accountants

24.       Powers of Attorney
                  





                                      -7-
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 16830}]
{"company-data": {"conformed-name": "NORTHERN TRUST CORP", "cik": "0000073124", "assigned-sic": "6022", "irs-number": "362723087", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-52623", "film-number": "98619940"}, "business-address": {"street1": "50 S LA SALLE ST", "city": "CHICAGO", "state": "IL", "zip": "60675", "phone": "3126306000"}, "former-company": {"former-conformed-name": "NORTRUST CORP", "date-changed": "19780525"}}
Registration Statement No. 333-_____

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                              __________________

                                   FORM S-8

                            REGISTRATION STATEMENT
                                     Under
                          The Securities Act of 1933

                          Northern Trust Corporation
              (Exact name of issuer as specified in its charter)

       Delaware                                           36-2723087
(State of Incorporation)                       (IRS Employer Identification No.)
               50 South LaSalle Street, Chicago, Illinois 60675

             Northern Trust Corporation Deferred Compensation Plan
                             (Full Title of Plan)

                         Peter L. Rossiter,
                         Executive Vice President and General Counsel
                         50 South LaSalle Street
                         Chicago, Illinois 60675
                         (Name and Address of Agent for Service)

                                (312) 630-6000
____________________________________________________________________________
        (Telephone number, including area codes, of agents for service)

                        CALCULATION OF REGISTRATION FEE
Proposed      Proposed
                                       Maximum       Maximum
                        Amount         Offering      Aggregate     Amount of
Title of Securities     To Be          Price Per     Offering      Registration
to be Registered (1)    Registered     Obligation    Price (2)     Fee
Deferred Compensation   $52,500,000       100%       $52,500,000   $15,487.50
Obligations
(1)  The Deferred Compensation Obligations are unsecured obligations of Northern
     Trust Corporation to pay deferred compensation in the future in accordance
     with the terms of the Northern Trust Corporation Deferred Compensation
     Plan.

(2)  Estimated solely for the purpose of determining the registration fee.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

                                        
Item 3. Incorporation of Documents by Reference.

     The following documents are incorporated herein by reference:

     (a)  The Annual Report on Form 10-K of Northern Trust Corporation (the
          "Registrant") for the fiscal year ended December 31, 1997;

     (b)  The Registrant's Quarterly Report on Form 10-Q for the quarter ended
          March 31, 1998; and

     (c)  The Registrant's Current Reports on Form 8-K filed on January 21,
          April 3, and April 21, 1998.

     All documents filed by the Registrant pursuant to Sections 13(a), 13(c),
14 and 15(d) of the Securities Exchange Act of 1934 (the "1934 Act") subsequent
to the date hereof and prior to the termination of the offering of the
securities registered pursuant to this Registration Statement shall be deemed to
be incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained in a
document incorporated or deemed to be incorporated by reference herein shall be
deemed to be modified or superseded for purposes of this Registration Statement
to the extent that a statement contained herein or in any other subsequently
filed document which also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

Item 4. Description of Securities.

     The Northern Trust Corporation Deferred Compensation Plan Obligations
("Obligations") are general unsecured obligations of the Registrant to pay
deferred compensation in the future in accordance with the terms of the Northern
Trust Corporation Deferred Compensation Plan ("Plan") from the general assets of
the Registrant, and rank pari passu with other unsecured and unsubordinated
indebtedness of the Registrant from time to time outstanding.
The Obligations are not subject to redemption, in whole or in part. The 
amount of compensation to be deferred by each participating employee (each a 
"Participant") will be determined in accordance with the Plan based on elections
by each Participant. Each Obligation will be payable on a date selected by each
Participant in accordance with the terms of the Plan. The Obligations will be
invested in one or more investment vehicles selected by a committee responsible
for administration of the Plan. Each Participant's Obligation will be adjusted
to reflect the investment experience, whether positive or negative, of the
selected vehicles, including any appreciation or depreciation. The Obligations
will be denominated in United States dollars.

     The Registrant reserves the right to amend or terminate the Plan at any
time, provided that no amendment or termination may directly or indirectly
reduce the balance of any Obligations as of the effective date of the amendment
or termination.

     The Obligations are not convertible into any other obligations of the
Participant.  The Obligations will not have the benefit of a negative pledge or
any other affirmative or negative covenant on the part of the Registrant.  The
Obligations are funded by means of a "rabbi trust" for which Harris Trust and 
Savings Bank, Chicago, Illinois, an independent corporate trustee has been
appointed. The trustee will not have the authority for, and each Participant
will be responsible for acting independently with respect to, among other
things, the giving of notices, responding to any requests for consents, waivers
or amendments pertaining to the Obligations, enforcing covenants and taking
further action upon a default.

Item 5. Interests of Named Experts and Counsel.

     Peter L. Rossiter, Executive Vice President and General Counsel of the 
Registrant, has furnished the opinion attached as Exhibit 5 to this registration
statement with respect to the validity of the securities being registered 
hereunder. As of May 1, 1998, Mr. Rossiter owned 130,183 shares of Common Stock 
of the Registrant, which includes 114,870 shares issuable pursuant to stock 
options.

Item 6. Indemnification of Directors and Officers.

     Section 145 of the Delaware General Corporation Law and Article Eighth of
the Corporation's Restated Certificate of Incorporation provide for
indemnification of the Corporation's directors and officers in a variety of
circumstances, which may include liabilities under the Securities Act of 1933,
as amended (the "1933 Act").  The general effect of these provisions is to
provide that the Corporation shall indemnify its directors and officers against
all liabilities and expenses reasonably incurred in connection with the defense
or settlement of any judicial or administrative proceedings in which they become
involved by reason of their status as corporate directors or officers, if they
acted in good faith and in the reasonable belief that their conduct was neither
unlawful (in the case of criminal proceedings) nor inconsistent with the best
interests of the Corporation.  With respect to legal proceedings by or in the
right of the Corporation in which a director or officer is adjudged liable for
improper performance of his duty to the Corporation, indemnification is limited
by such provisions to that amount which is permitted by the court.  In addition,
the Corporation has purchased insurance as permitted by Delaware law on behalf
of directors, officers, employees or agents, which may cover liabilities under
the 1933 Act.

                                      -2-
Item 7. Exemption from Registration Claimed.

     Not applicable.

Item 8. Exhibits.

     The Exhibits filed herewith are set forth on the Exhibit Index filed as
part of this registration statement.

Item 9. Undertakings.

     (a) The undersigned Registrant hereby undertakes:

          (1) To file, during any period in which offers or sales are being 
     made, a post-effective amendment to this registration statement:

               (i) To include any prospectus required by Section 10(a)(3) of the
          1933 Act;

               (ii) To reflect in the prospectus any facts or events arising
          after the effective date of the registration statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the registration statement. Notwithstanding the foregoing, any
          increase or decrease in volume of securities offered (if the total
          dollar value of securities offered would not exceed that which was
          registered) and any deviation from the low or high and of the
          estimated maximum offering range may be reflected in the form of
          prospectus filed with the Commission pursuant to Rule 424(b) if, in
          the aggregate, the changes in volume and price represent no more than
          20 percent change in the maximum aggregate offering price set forth in
          the "Calculation of Registration Fee" table in the effective
          registration statement; and

               (iii) To include any material information with respect to the
          plan of distribution not previously disclosed in the registration
          statement or any material change to such information in the
          registration statement;

     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if
     the registration statement is on Form S-3, Form S-8 or Form F-3, and the
     information required to be included in a post-effective amendment by those
     paragraphs is contained in periodic reports filed with or furnished to the
     Commission by the Registrant pursuant to Section 13 or 15(d) of the 1934
     Act that are incorporated by reference in the registration statement.

                                      -3-
(2) That, for the purpose of determining any liability under the l933
     Act, each such post-effective amendment shall be deemed to be a new
     registration statement relating to the securities offered therein, and the
     offering of such securities at that time shall be deemed to be the initial
     bona fide offering thereof.

          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.

     (b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (c) Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the 1933 Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.

                                      -4-
SIGNATURES

The Registrant

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago and State of Illinois on the 14th day of May,
1998.

                                   NORTHERN TRUST CORPORATION
                                   By   /s/ Peter L. Rossiter
                                        ---------------------
                                   Peter L. Rossiter
                                   Executive Vice President and General Counsel

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons in the
capacities indicated on the 14th day of May, 1998.

Signature                              Title

WILLIAM A. OSBORN*                     Chairman of the Board
----------------------                 President, Chief Executive
William A. Osborn                      Officer and Director

BARRY G. HASTINGS*                     President, Chief Operating
----------------------                 Officer and Director
Barry G. Hastings

PERRY R. PERO*                         Senior Executive Vice President
----------------------                 and Chief Financial Officer
Perry R. Pero

HARRY W. SHORT*                        Senior Vice President
----------------------                 and Controller
Harry W. Short

DUANE L. BURNHAM *                     Director
----------------------
Duane L. Burnham

DOLORES E. CROSS*                      Director
----------------------
Dolores E. Cross

SUSAN CROWN*                           Director
----------------------
Susan Crown

                                      -5-
Signature                  Title

ROBERT S. HAMADA*          Director
----------------------     
Robert S. Hamada

ROBERT A. HELMAN*          Director
----------------------     
Robert A. Helman

ARTHUR L. KELLY*           Director
----------------------     
Arthur L. Kelly

FREDERICK A. KREHBIEL*     Director
----------------------     
Frederick A. Krehbiel

WILLIAM G. MITCHELL*       Director
----------------------     
William G. Mitchell

EDWARD J. MOONEY*          Director
----------------------     
Edward J. Mooney

HAROLD B. SMITH*           Director
----------------------     
Harold B. Smith

WILLIAM D. SMITHBURG*      Director
----------------------     
William D. Smithburg

BIDE L. THOMAS*            Director
----------------------     
Bide L. Thomas

     *Peter L. Rossiter, pursuant to powers of attorney duly executed by each of
the above Directors and Officers of Northern Trust Corporation and filed with
the Securities and Exchange Commission in Washington, D.C., hereby executes this
registration statement on behalf of each of the persons named above in the
capacity set forth opposite his or her name.

       /s/ Peter L. Rossiter                  May 14, 1998
       ---------------------                         
       Peter L. Rossiter
       (Attorney-in-fact)

                                      -6-
EXHIBIT INDEX
                                        
                                        

Exhibit
Number    Description                                      Page No.
------    -----------                                      --------

4.1       Restated Certificate of Incorporation
          (Incorporated by reference to Registrant's 
          Quarterly Report on Form 10-Q for the 
          quarter ended March 31, 1997)

4.2.      By-laws, as amended
          (Incorporated by reference to Registrant's 
          Quarterly Report on Form 10-Q for the 
          quarter ended March 31, 1996)

5.        Opinion of Counsel

23.1      Consent of Counsel
          (Contained in its opinion filed as Exhibit 5)
23.2      Consent of Independent Public Accountants

24.       Powers of Attorney
                  

                                      -7-