EXHIBIT 4 (r)


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THESE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT PURPOSES ONLY AND MAY NOT BE
TRANSFERRED UNTIL: (i) A REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF
1933, AS AMENDED (THE "ACT") SHALL HAVE BECOME EFFECTIVE WITH RESPECT THERETO;
OR (ii) RECEIPT BY THE ISSUER OF AN OPINION OF COUNSEL REASONABLY SATISFACTORY
TO THE ISSUER TO THE EFFECT THAT REGISTRATION UNDER THE ACT IS NOT REQUIRED IN
CONNECTION WITH SUCH PROPOSED TRANSFER AND THAT SUCH TRANSFER IS NOT IN
VIOLATION OF ANY APPLICABLE FEDERAL, STATE OR FOREIGN SECURITIES LAWS. THIS
LEGEND SHALL BE ENDORSED UPON ANY SECURITIES ISSUED IN EXCHANGE FOR THESE
SECURITIES; PROVIDED, HOWEVER, THAT IN NO EVENT ARE THESE SECURITIES
TRANSFERRABLE PRIOR TO THE EARLIER OF: (i) THE EFFECTIVE DATE OF THE COMPANY'S
PROPOSED INITIAL PUBLIC OFFERING OF ITS SECURITIES; OR (ii) MARCH 31, 1998.

                              THE TIREX CORPORATION
                     10% CONVERTIBLE SUBORDINATED DEBENTURE

No. 1                                                                  $250,000

      THE TIREX CORPORATION a Delaware corporation (the "Company"), for value
received, hereby promises to pay in currency of the United States of America to
          or registered assigns (the "Payee" or "Holder") in accordance with the
provisions contained herein, at the offices of the Company, the principal amount
of Two Hundred and Fifty Thousand Dollars ($250,000), along with interest on
such principal amount at the rate of ten percent (10%) per annum, payable in
arrears, from the date hereof through the Maturity Date in the following manner:
The entire principal face value of this Debenture and all accrued and unpaid
interest hereon shall be due and payable on the first of the following to occur:
(i) the conversion of this Debenture pursuant to Section 1 below; (ii) the
completion and closing of an underwritten public offering of the securities of
the Company yielding gross proceeds to the Company of not less than $8,000,000;
(iii) any debt or equity financing of the Company in excess of $4,500,000; or
(iv) one year from the date of this Debenture.

      This Debenture is issued pursuant to a Securities Purchase Agreement dated
April 9, 1998, between the Company and the Payee (the "Subscription Agreement"),
and is subject to the terms of a Registration Rights Agreement dated April 9,
1998, between the Company and the Payee (the "Registration Rights Agreement")
and conversion of the Debenture in accordance with its terms may have an adverse
affect on a Warrant to purchase Common Stock of the Company dated April 9, 1998
(the "Warrant") copies of each of which are available for inspection at the
Company's offices located at 740 St. Maurice, Suite 201, Montreal, Quebec #3C
lL5. Notwithstanding any provision to the contrary contained herein,


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this Debenture is subject to certain terms, conditions, covenants and agreements
contained in each of the Securities Purchase Agreement and Registration Rights
Agreement. Any transferee or transferees of this Debenture, by their acceptance
hereof, assume the obligations of the Subscriber in each of the Securities
Purchase Agreement and Registration Rights Agreement with respect to the
conditions and procedures for transfer of this Debenture. Reference to each of
the Securities Purchase Agreement and Registration Rights Agreement shall in no
way impair the absolute and unconditional obligation of the Company to pay both
principal and interest of this Debenture as provided for herein.

      1. CONVERSION, REDEMPTION AND REGISTRATION.

      (a) This Debenture is convertible in whole or in part at any time into
that number of shares of the Company's common stock, par value $.01 per share
("Common Stock") as is obtained by dividing the then unpaid principal face value
of the note by an amount equal to 85% of the average closing bid price of the
Common Stock as reported by the National Association of Securities Dealers
Automated Quotation Small-Cap Market System ("Small Cap") averaged over the five
day period prior to the Company receiving a notice of conversion. In the event
the Company's Common Stock is not then traded on the Small-Cap, the conversion
price will be 85% of the average closing bid price of the Common Stock on the
National Association of Securities Dealers, Inc. ("NASD") Over-the-Counter
Electronic Bulletin Board Service, in such five day period. If the Common Stock
is not listed on any securities exchange at the time a notice of conversion is
issued, the conversion price shall be such price as is determined as the fair
and reasonable price a third party not affiliated with the Company would pay for
the Common Stock as determined by the Board of Directors. At the election of the
Payee, all accrued but unpaid interest hereon may also be converted in Common
Stock in the manner prescribed herein. Such shares of Common Stock are referred
to herein as the "Conversion Shares." In the event the Company's proposed
initial public offering is not completed prior to March 31, 1998, the conversion
price referenced herein shall be reduced from 85% to 75%. All converted shares
of Common Stock shall have customary "piggyback" registration rights and demand
registration rights as described herein. The Company has an obligation to
register all of the Conversion Shares with the Securities and Exchange
Commission (the "SEC") pursuant to the Registration Rights Agreement. This
Debenture may be partially converted and in case of such partial conversion, the
Company, upon surrender hereof, will deliver to the Holder a new Debenture
representing the principal face value which has not been converted.

      In the event any portion of this Debenture is converted prior to March 31,
1998, the Holder hereof, who is also a Holder of Warrants, shall lose the right
to exercise each Holder's Warrants as such portion relates pro rata to the
portion of this Debenture converted. By way of example, if this Debenture has a
face value of $25,000, the Holder has Warrants to purchase 100,000 shares of
Common Stock and the Holder converts $5,000 of this Debenture (20% of the
Debenture) prior to March 31, 1998, such Holder and all transferees and assigns
shall lose forever the right to exercise 20,000 Warrants (20% of the Warrants).

      (b) This Debenture is convertible into shares of Common Stock at any time;
provided, however, that the convertibility with respect to this Debenture shall
terminate


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beginning one day preceding the filing by the Company of a registration
statement registering the Conversion Shares and a new conversion period shall
commence immediately following the effectiveness of such registration statement
with the SEC pursuant to which this Debenture shall again become convertible at
any time; provided, further, however, that in the event a registration statement
is filed and not declared effective within 120 days of the date of filing of
such registration statement with the SEC, a new conversion period shall commence
pursuant to which this Debenture shall again become convertible at any time. The
Holder hereof shall have no conversion rights following payment in full of the
principal and interest owed by the Company to the Holder hereof. The conversion
rights represented by this Debenture may be exercised, in whole or in part, by
the Holder at any time within the period specified in this Section l(b) by
surrender of this Debenture for cancellation at the principal executive office
of the Company (or at such other office or agency of the Company as it may
designate by notice in writing to the Holder at the address of the Holder
appearing on the books of the Company), together with the amount of applicable
stock transfer taxes, if any. This Debenture shall be deemed to have been
converted, in whole or in part to the extent specified, immediately prior to the
close of business on the date on which all of the applicable provisions of this
Section l(b) are satisfied. The Company will transmit the certificates
representing the Conversion Shares via express courier within five business days
after receipt by the Company of all the documentation required by this Section
l(b).

      (c) The Holder of this Debenture shall not, by virtue hereof, be entitled
to any rights of a stockholder in the Company, either at law or in equity;
provided, however, that in the event any certificate representing Conversion
Shares is issued to the Holder hereof upon conversion of some or all of this
Debenture, such Holder shall, for all purposes, be deemed to have become the
holder of record of such Conversion Shares on the date on which all of the
applicable provisions of Section 1 have been met, irrespective of the date of
delivery of such share certificate.

      (d) In the sole discretion of the Holder hereof, such Holder may require
that the Company assign the obligations of the Company described in this
Debenture to any successor of the Company if the Company is not the surviving
entity of a merger or consolidation. The Company must give the Holder hereof
fifteen (15) business days notice of the terms of any such consolidation or
merger and the terms thereof.

      (e) Unless registered with the SEC, each certificate evidencing the
Conversion Shares, and any certificates issued upon transfer or exchange of the
foregoing shall be stamped or imprinted with the following legend:

      THESE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT PURPOSES ONLY AND MAY
      NOT BE TRANSFERRED UNTIL: (I) A REGISTRATION STATEMENT UNDER THE
      SECURITIES ACT OF 1933, AS AMENDED (THE "ACT") SHALL HAVE BECOME EFFECTIVE
      WITH RESPECT THERETO; OR (II) RECEIPT BY THE ISSUER OF AN OPINION OF
      COUNSEL REASONABLY SATISFACTORY TO THE ISSUER TO THE EFFECT THAT
      REGISTRATION UNDER THE ACT IS


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      NOT REQUIRED IN CONNECTION WITH SUCH PROPOSED TRANSFER AND THAT SUCH
      TRANSFER IS NOT IN VIOLATION OF ANY APPLICABLE STATE, FEDERAL OR FOREIGN
      SECURITIES LAWS. THE SHARES UNDERLYING THESE SECURITIES MAY BE SUBJECT TO
      A LOCK UP AGREEMENT

      The legend set forth above shall be removed and the Company shall issue a
certificate without such legend to the holder of the Conversion Shares upon
which it is stamped, if, unless otherwise required by state securities laws, (i)
the Conversion Shares are registered under the Act, or (b) in connection with a
transfer, such holder provides the Company with an opinion of counsel reasonably
satisfactory to the Company, to the effect that a transfer thereof may be made
without registration under the Act and that such transfer does not violate any
applicable state or foreign securities laws.

      (f) This Debenture may be redeemed by the Holder at any time after the
Maturity Date at 100% of the principal face value of this Debenture plus all
accrued but unpaid interest; provided, however, that any redemption effectuated
after May 31, 1998 shall be made at 125% of the principal face value of this
Debenture plus all accrued but unpaid interest.

      (g) If for any reason, the Company fails to register the Conversion
Shares, or to keep the Registration Statement respecting the Conversion Shares
effective, then the holders of the Debentures shall have the following
additional registration rights: (i) During the one-year period following May 31,
1998, on one occasion only, the Company shall, pursuant to the written demand of
the holders of 50% or more of the aggregate principal amount of the Debentures,
file a registration statement under the Securities Act, covering the Conversion
Shares, as promptly as practicable following such demand; The Company shall use
its best efforts to cause such registration statement to be declared effective
by the SEC within 120 days following such demand and to keep such registration
statement effective at all times until all of the Debentures are converted and
the delivery of a prospectus is no longer required in connection with any resale
of the Conversion Shares, and (ii) If, at any time during the one-year period
following May 31, 1998, the Company intends to file a registration statement,
under the Securities Act, then, not later than twenty days prior to the intended
filing date for such registration statement, the Company shall give written
notice to the Holder of its intention to file a registration statement and the
Holder shall have the right, upon written instructions, received by the Company
within ten days of the intended filing date of the registration statement, to
have included in such registration statement the number of Conversion Shares
issued or issuable to them as such Holder shall so instruct. The Company shall
use its best efforts to cause such registration statement to be declared
effective by the SEC as promptly as possible and to keep such registration
statement effective at all times, as set forth above. The foregoing provisions
of this subsection l(g) shall not be deemed to change or modify any provisions
contained in the Registration Rights Agreement and shall be in addition to any
rights granted to the Holder pursuant to the Registration Rights Agreement.


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<PAGE>

      2. COVENANTS OF COMPANY.

      The Company covenants and agrees that, so long as any portion of this
Debenture shall be outstanding:

      (a) it will promptly pay and discharge all lawful taxes, assessments, and
governmental charges or levies imposed upon the Company or upon its income and
profits, or upon any of its property, before the same shall become in default,
as well as all lawful claims for labor, materials and supplies which, if unpaid,
might become a lien or charge upon such properties or any part thereof;
provided. however, that the Company shall not be required to pay and discharge
any such tax, assessment, charge, levy or claim so long as the validity thereof
shall be contested in good faith by appropriate proceedings and the Company
shall set aside on its books adequate reserves with respect to any such tax,
assessment, charge, levy or claim so contested;

      (b) it will do or cause to be done all things reasonably necessary to
preserve and keep in full force and effect its corporate existence, rights and
franchises and comply with all laws applicable to the Company, except where the
failure to comply would not have a material adverse effect on the Company;

      (c) it will at all times keep true and correct books, records and
accounts;

      (d) it will at all times maintain, preserve, protect and keep its property
used or useful in the conduct of its business in good repair, working order and
condition, and from time to time make all necessary and proper repairs,
renewals, replacements, betterments and improvements thereto as shall be
reasonably required in the conduct of its business;

      (e) it will to the extent necessary for the operation of its business,
keep adequately insured by financially sound and reputable insurers, all
property of a character usually insured by similar corporations and carry such
other insurance as is usually carried by similar corporations; and

      (f) it will timely make all filings required under the Securities Exchange
Act of 1934, as amended;

      (g) it will use its best efforts to maintain the listing of its Common
Stock on all public stock exchanges on which the Common Stock is approved for
listing.

      (h) that all shares of Common Stock issuable upon conversion of this
Debenture will, upon delivery, be duly and validly authorized and issued,
fully-paid and non-assessable with no personal liability attaching to the Holder
thereof; and

      (i) it will at all times on and subsequent to the date at which this
Debenture becomes convertible and prior to expiration of this Debenture reserve
and keep available an authorized number of shares of its Common Stock and other
applicable securities sufficient to permit the exercise in full of all
outstanding options, warrants and rights, including this


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        3.  Issuance  of  Certificates.  As soon as  possible  after any full or
 partial  conversion of this  Debenture,  but in any event no more than five (5)
 business days, the Company, at its expense, will cause to be issued in the name
 of and delivered to the Holder of this Debenture, a certificate or certificates
 for the number of fully paid and non-assessable shares of Common Stock to which
 such Holder  shall be  entitled on such  conversion.  No  fractional  shares of
 Common Stock will be issued on exercise of this Debenture.  If, on any exercise
 of this Debenture,  a fractional  share results,  the Company will pay the cash
 value of that fractional share, calculated on the basis of the conversion price
 per share.

      4. ADDITIONAL PROVISIONS.

      This Debenture is subject to the following additional provisions:

      (a) The Company shall be entitled to withhold from all payments of
principal of and interest on this Debenture any amounts required to be withheld
under the applicable provisions of the United States income tax laws or other
applicable laws at the time of such payments.

      (b) This Debenture has been issued subject to investment representations
of the original purchaser hereof and may be transferred or exchanged only in
compliance with the Act, any applicable state securities laws and any applicable
securities laws of any other jurisdiction. Prior to due presentment for transfer
of this Debenture, the Company and any agent of the Company may treat the person
in whose name this Debenture is duly registered on the Company's Debenture
Register as the owner hereof for the purpose of receiving payment as herein
provided and for all other purposes, whether or not this Debenture is overdue,
and neither the Company nor any such agent shall be affected by notice to the
contrary.

      (c) No provision of this Debenture shall alter or impair the obligation of
the Company, which is absolute and unconditional, to pay the principal of, and
interest on, this Debenture at the time, place and rate, and in the coin or
currency, herein prescribed. This Debenture is the direct obligation of the
Company. This Debenture ranks equally and ratably with all other notes now or
hereafter issued under the terms set forth herein.

      (d) No recourse shall be had for the payment of the principal of, or the
interest on, this Debenture, or for any claim based hereon, or otherwise in
respect hereof, against any incorporator, shareholder, officer, director or
control person, as such, past, present or future, of the Company or any
successor corporation, whether by virtue of any constitution, statute or rule of
law, or by the enforcement of any assessment or penalty or otherwise, all such
liability being, by the acceptance hereof and as part of the consideration for
the issue hereof, expressly waived and released.

      (e) The Holder of this Debenture, by acceptance hereof, agrees that this
Debenture is being acquired for investment and that such Holder will not offer,
sell or otherwise dispose of this Debenture until: (i) a registration statement
under the Act shall have become effective with respect thereto; or (ii) receipt
by the Company of an opinion of counsel reasonably satisfactory to the Company
to the effect that registration under the Act is


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not required in connection with such proposed transfer and that such transfer is
not in violation of any applicable state or foreign securities laws.

      5. EVENTS OF DEFAULT.

      (a) This Debenture shall become and be due and payable upon written demand
made by the Holder hereof if one or more of the following events, hereinafter
called events of default, shall happen and be continuing:

            (i) default in the payment of principal or interest on this
      Debenture when and as the same shall become due and payable, whether by
      acceleration or otherwise.

            (ii) default in the due observance or performance of any material
      covenant, condition or agreement on the part of the Company to be observed
      or performed pursuant to the terms hereof if such default shall continue
      uncured for five (5) days after written notice thereof, specifying such
      default, shall have been given to the Company by the Holder of the
      Debenture;

            (iii) The Company shall (1) commence any proceeding or other action
      relating to it in bankruptcy or seek reorganization, arrangement,
      readjustment of its debts, receivership, dissolution, liquidation,
      winding-up, composition or any other relief under the Bankruptcy Act, as
      amended, or under any other insolvency, reorganization, liquidation,
      dissolution, arrangement, composition, readjustment of debt or any other
      similar act or law; of any jurisdiction, domestic or foreign, now or
      hereafter existing; or (2) admit the material allegations of any petition
      or pleading in connection with any such proceeding; or (3) apply for, or
      consent or acquiesce to, the appointment of a receiver, conservator,
      trustee or similar officer for it or for all or a substantial part of its
      property; or (4) make a general assignrnent for the benefit of creditors;

            (iv) Commencement of any proceeding or the taking of any other
      action against the Company in bankruptcy, or seeking reorganization,
      arrangement, readjustment of its debts, liquidation, dissolution,
      arrangement, composition, readjustment of debt or any other similar act or
      law of any jurisdiction, domestic or foreign, now or hereafter existing
      and the continuance of any such events for sixty (60) days undismissed,
      unbonded or undischarged; or the appointment of a receiver, conservator,
      trustee or similar officer of the Company or for all or substantially all
      of its property and the continuance of any such events for sixty (60) days
      undismissed, unbonded or undischarged.

            (v) a breach of the Company's representations, warranties or
      covenants contained in the Securities Purchase Agreement;

            (vi) a breach of the Company's representations, warranties or
      covenants contained in the Registration Rights Agreement.

            (vii) the sale or other disposition or transfer by the Company or
      any subsidiary of substantially all of its assets;


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<PAGE>

            (viii) the merger by the Company or any subsidiary with or into
      another corporation, other than for purposes of changing domicile, where
      the Company is not the surviving corporation.

      (b) The Company agrees that notice of the occurrence of any event of
default will be promptly given to the Holder at his or her registered address by
certified mail.

      (c) In case any one or more of the events of default specified above shall
occur and continue to occur, the Holder of this Debenture may proceed to protect
and enforce his rights by suit in the specified performance of any covenant or
agreement contained in this Debenture or in aid of the exercise of any power
granted in this Debenture or may proceed to enforce the payment of this
Debenture or to enforce any other legal or equitable rights as such Holder may
have.

      6. SUBORDINATION OF OTHER INDEBTEDNESS; SECURITY

      (a) The Company, for itself, its successors and assigns, covenants and
agrees, and each Holder of this Debenture, by his acceptance thereof, likewise
covenants and agrees, that the payment of the principal of and interest on, each
and all of the Debentures is hereby expressly subordinated in right of payment,
to the prior payment in full of any indebtedness now outstanding or hereinafter
incurred, to a bank, financial institution engaged in lending money, insurance
company or other similar institutional lender ("Senior Indebtedness"). Each
Holder of this Debenture shall, upon the Company's reasonable request, execute
and deliver to the Company such documents as may be necessary or appropriate to
evidence or confirm the foregoing subordination.

      (b) Notwithstanding the subordination described in Section 6(a) above,
until: (i) the occurrence of an event of default by the Company under any
document evidencing Senior Indebtedness; or (ii) the Company makes any
assignment for the benefit of creditors; or (iii) any bankruptcy proceedings are
instituted by or against the Company; or (iv) any receiver for the Company's
business or assets is appointed; or (v) there is any dissolution or winding up
of the affairs of the Company, whichever of the foregoing occurs earliest, the
Company may make and the Holders of this Debenture may receive any and all
payments due under this Debenture.

      (c) In the event of any insolvency or bankruptcy (voluntary or
involuntary) proceedings or any receivership, liquidation, reorganization or
other similar proceedings in connection therewith, related to the Company or to
its creditors, as such, or to its property, or in the event of any proceedings
for voluntary liquidation, dissolution or other winding up of the Company,
whether or not involving insolvency or bankruptcy, then the holders of Senior
Indebtedness shall be entitled to receive payment in full of all principal and
interest on all Senior Indebtedness before the Holder of this Debenture is
entitled to receive any payment on account of principal or interest on this
Debenture, and to that end the holder of Senior Indebtedness shall be entitled
to receive for application in payment thereof any payment or distribution of any
kind or character, whether in cash or property or securities, which may be
payable or deliverable in any such proceedings in respect of this Debenture,


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except securities which are subordinate and junior in right or payment to the
payment of Senior Indebtedness.

      (d) In the event that this Debenture is declared due and payable before
its expressed maturity because of the occurrence of an event of default
hereunder (under circumstances when the provisions of the foregoing clause (c)
shall not be applicable), the holders of Senior Indebtedness outstanding at the
time the Debenture so becomes due and payable because of such occurrence of a
default thereunder shall be entitled to receive payment in full of all principal
and interest on all Senior Indebtedness before the Holder of the Debenture is
entitled to receive payment on account of the principal or interest upon this
Debenture.

      (e) In the event of any default in payment of any principal of or any
interest on any Senior Indebtedness and during the continuance of any such
default, no amount shall be paid by the Company and the Holder of this Debenture
shall not be entitled to receive any amount, in respect of the principal of or
interest on the Debenture. No present or future holder of Senior Indebtedness
shall be prejudiced in his right to enforce subordination of this Debenture by
any act or failure to act on the part of the Company. The Company shall render
written notice to the Holder of this Debenture immediately upon the occurrence
of each such default in the payment of any principal of or any interest on any
Senior Indebtedness describing such default in detail.

      (f) Nothing contained in the subordination herein is intended to or shall
impair, as between the Company, its creditors other than the holders of Senior
Indebtedness, and the Holder of this Debenture, the obligation of the Company,
which is absolute and unconditional, to pay to the persons entitled thereto
under the terms thereof the principal of and interest on this Debenture, as and
when the same shall become due and payable in accordance with its terms, or to
affect the relative rights of the Holder of this Debenture and creditors of the
Company other than the holders of Senior Indebtedness, nor shall anything herein
prevent the Holder of this Debenture from exercising all remedies otherwise
permitted by applicable law upon default under the Debenture, subject to the
rights, if any, under the subordination herein, of the holders of Senior
Indebtedness in respect of cash, property or securities of the Company received
upon the exercise of any such remedy.

      7. MISCELLANEOUS.

      (a) This Debenture has been issued by the Company pursuant to
authorization of the Board of Directors of the Company which provides for an
aggregate of up to $700,000 in face amount of identical Debentures to be issued.

      (b) The Company may consider and treat the person in whose name this
Debenture shall be registered as the absolute owner thereof for all purposes
whatsoever (whether or not this Debenture shall be overdue) and the Company
shall not be affected by any notice to the contrary. The registered owner of
this Debenture shall have the right to transfer it by assignment (subject to the
limitations on transfer contained in this Debenture and in the Securities
Purchase Agreement) and the transferee thereof shall, upon his registration as
owner of this Debenture, become vested with all the powers and rights of the


                                                                             183
<PAGE>

transferor. Registration of any new owner shall take place upon presentation of
this Debenture to the Company at its offices at 740 St. Maurice, Suite 201,
Montreal, Canada #3C lL5, together with a duly authenticated assignment. In case
of transfer by operation of law, the transferee agrees to notify the Company of
such transfer and of his address, and to submit appropriate evidence regarding
the transfer so that this Debenture may be registered in the name of the
transferee. This Debenture is transferable only on the books of the Company by
the holder hereof, in person or by attorney, on the surrender hereof, duly
endorsed. Cornmunications sent to any registered owner shall be effective as
against all holders or transferees of the Debenture not registered at the time
of sending the communication.

      (b) Payment of the principal and outstanding interest shall be made to the
registered owner of this Debenture upon presentation of this Debenture upon or
after maturity.

      (c) The Company hereby waives presentment for payment, demand and protest
and notice of dishonor.

      (d) Neither this Debenture nor any term hereof may be changed, waived
discharged or terminated orally, but only by an instrument in writing signed by
the party against whom enforcement of the change, waiver, discharge or
termination is sought.

      (e) All notices, requests, demands and other communications to the Company
hereunder shall be in writing and shall be deemed given if delivered personally
or mailed by certified or registered mail, postage prepaid, return receipt
requested or via facsimile, addressed as follows or to such other addresses as
the Company may designate in writing to the holder hereof:

      The Tirex Corporation 
      740 St. Maurice, Suite 201 
      Montreal, Quebec #3C lL5
      Attention: Terrence C. Byrne, President 
      Fax No.: (514) 878-9847

      (e) This Debenture shall be construed and enforced in accordance with the
internal laws of the State of New York, without regard to such State's
principles respecting the conflicts of law.


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<PAGE>

      (f) The terms of this Debenture shall be binding on the Company and its
successors and assigns.

      IN WIINESS WHEREOF, the Company has caused this Debenture to be signed in
its name by the undersigned.

 Dated: April 9, 1998

                                             THE TIREX  CORPORATION

                                             By:________________________________


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