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                                                                     Exhibit 2.4


                          REGISTRATION RIGHTS AGREEMENT


                  THIS REGISTRATION RIGHTS AGREEMENT, dated as of May 14, 2001
between Coriander Enterprises Limited ("Purchaser") and National Scientific
Corporation, a Texas corporation (the "Company").

                  WHEREAS, simultaneously with the execution and delivery of
this Agreement, the parties shall enter into the Common Stock Purchase
Agreement, dated as of the date hereof, (the "Purchase Agreement") pursuant to
which the Purchaser has committed to purchase up to $24,000,000 of the Company's
Common Stock (terms not defined herein shall have the meanings ascribed to them
in the Purchase Agreement) and the Warrant; and

                  WHEREAS, the execution and delivery of this Agreement and
granting to the Purchaser of the registration rights set forth herein with
respect to the Shares is a component part of the transaction contemplated under
the Purchase Agreement.

                  NOW, THEREFORE, the parties hereto mutually agree as follows:

                  Section 1. Registrable Securities. As used herein the term
"Registrable Security" means all Shares that (i) have not been sold under the
Registration Statement, (ii) have not been sold under circumstances under which
all of the applicable conditions of Rule 144 (or any similar provision then in
force) under the Securities Act ("Rule 144") are met, (iii) have not been
otherwise transferred to persons who may trade such Shares without restriction
under the Securities Act, and the Company has delivered a new certificate or
other evidence of ownership for such Shares not bearing a restrictive legend, or
(iv) may not be sold without any time, volume or manner limitations pursuant to
Rule 144(k) (or any similar provision then in effect) under the Securities Act.
In the event of any merger, reorganization, consolidation, recapitalization or
other change in corporate structure affecting the Common Stock, such adjustment
shall be deemed to be made in the definition of "Registrable Security" as is
appropriate in order to prevent any dilution or enlargement of the rights
granted pursuant to this Agreement.

                  Section 2. Restrictions on Transfer. The Purchaser
acknowledges and understands that in the absence of an effective Registration
Statement authorizing the resale of the Shares as provided herein, the Shares
are "restricted securities" as defined in Rule 144. The Purchaser understands
that no disposition or transfer of the Shares may be made by Purchaser in the
absence of (i) an opinion of counsel to the Purchaser, in form and substance
reasonably satisfactory to the Company, that such transfer may be made without
registration under the Securities Act or (ii) such registration.

                  With a view to making available to the Purchaser the benefits
of Rule 144, the Company agrees to:

                           (a) comply with the provisions of paragraph (c)(1) of
         Rule 144; and
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                           (b) to file with the Commission in a timely manner
         all reports and other documents required to be filed by the Company
         pursuant to Section 13 or 15(d) under the Exchange Act; and, if at any
         time it is not required to file such reports but in the past had been
         required to or did file such reports, it will, upon the request of the
         Purchaser, make available other information as required by, and so long
         as necessary to permit sales of, its Registrable Securities pursuant to
         Rule 144.

                  Section 3. Registration Rights With Respect to the Shares.

                           (a) The Company agrees that it will prepare and file
         with the Securities and Exchange Commission ("Commission"), within
         forty-five (45) days after the date hereof, a registration statement
         (on Form S-3 and/or SB-2, or other appropriate form of registration
         statement) under the Securities Act (the "Registration Statement"), at
         the sole expense of the Company (except as provided in Section 3(c)
         hereof), so as to permit a public offering and resale of the Shares
         under the Securities Act by Purchaser.

                           (b) The Company shall cause the Registration
         Statement to become effective within the earlier of (i) one hundred
         twenty (120) days of the date of filing the Registration Statement, or
         (ii) five (5) days after receiving written notice of SEC clearance and
         will within said five (5) days request acceleration of effectiveness.
         The Company will notify Purchaser of the effectiveness of the
         Registration Statement within one Trading Day of such event.

                           (c) The Company will maintain the Registration
         Statement or post-effective amendment filed under this Section 3 hereof
         effective under the Securities Act until the earliest of (i) the date
         that all the Registrable Securities have been disposed of pursuant to
         the Registration Statement, (ii) the date that all of the Registrable
         Securities have been sold pursuant to the Registration Statement, (iii)
         the date that all of the Registrable Securities have been otherwise
         transferred to persons who may trade such shares without restriction
         under the Securities Act, and the Company has delivered a new
         certificate or other evidence of ownership for such Shares not bearing
         a restrictive legend, (iv) the date that all of the Registrable
         Securities may be sold without any time, volume or manner limitations
         pursuant to Rule 144(k) or any similar provision then in effect under
         the Securities Act in the opinion of counsel to the Company, which
         counsel shall be reasonably acceptable to the Purchaser (the
         "Effectiveness Period").

                           (d) All fees, disbursements and out-of-pocket
         expenses and costs incurred by the Company in connection with the
         preparation and filing of the Registration Statement under subparagraph
         3(a) and in complying with applicable securities and Blue Sky laws
         (including, without limitation, all attorneys' fees of the Company)
         shall be borne by the Company. The Purchaser shall bear the cost of
         underwriting and/or brokerage discounts, fees and commissions, if any,
         applicable to the Shares being registered and the fees and expenses of
         its counsel.

                           (e) The Purchaser and its counsel shall have a
         reasonable period, not to exceed ten (10) Trading Days, to review the
         proposed Registration Statement or any


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         amendment thereto, prior to filing with the Commission, and the Company
         shall provide the Purchaser with copies of any comment letters received
         from the Commission with respect thereto within three (3) Trading Days
         of receipt thereof.

                           (f) The Company shall make reasonably available for
         inspection by Purchaser, any underwriter participating in any
         disposition pursuant to the Registration Statement, and any attorney,
         accountant or other agent retained by the Purchaser or any such
         underwriter all relevant financial and other records, pertinent
         corporate documents and properties of the Company and its subsidiaries,
         and cause the Company's officers, directors and employees to supply all
         information reasonably requested by the Purchaser or any such
         underwriter, attorney, accountant or agent in connection with the
         Registration Statement, in each case, as is customary for similar due
         diligence examinations; provided, however, that all records,
         information and documents that are designated in writing by the
         Company, in good faith, as confidential, proprietary or containing any
         material non-public information shall be kept confidential by the
         Purchaser and any such underwriter, attorney, accountant or agent,
         unless such disclosure is made pursuant to judicial process in a court
         proceeding (after first giving the Company an opportunity promptly to
         seek a protective order or otherwise limit the scope of the information
         sought to be disclosed) or is required by law, or such records,
         information or documents become available to the public generally or
         through a third party not in violation of an accompanying obligation of
         confidentiality. If the foregoing inspection and information gathering
         would otherwise disrupt the Company's conduct of its business, such
         inspection and information gathering shall, to the maximum extent
         possible, be coordinated on behalf of the Purchaser and the other
         parties entitled thereto by one firm of counsel designed by and on
         behalf of the majority in interest of Purchaser and other parties.

                           (g) The Company shall qualify any of the Shares for
         sale in such states as the Purchaser reasonably designates and shall
         furnish indemnification in the manner provided in Section 6 hereof.
         However, the Company shall not be required to qualify in any state
         which will require an escrow or other restriction relating to the
         Company and/or the sellers, or which will require the Company to
         qualify to do business in such state or require the Company to file
         therein any general consent to service of process.

                           (h) The Company at its expense will supply the
         Purchaser with copies of the Registration Statement and the final
         prospectus included therein (the "Prospectus") and other related
         documents in such quantities as may be reasonably requested by the
         Purchaser.

                           (i) The Company shall not be required by this Section
         3 to include the Purchaser's Shares in any Registration Statement which
         is to be filed if, in the opinion of counsel for both the Purchaser and
         the Company (or, should they not agree, in the opinion of another
         counsel experienced in securities law matters acceptable to counsel for
         the Purchaser and the Company) the proposed offering or other transfer
         as to which such registration is requested is exempt from applicable
         federal and state securities laws and would result in all purchasers or
         transferees obtaining securities which are not "restricted securities",
         as defined in Rule 144 under the Securities Act.


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                           (j) Subject to any federal or state securities laws,
         regulations or rules, if at any time or from time to time after the
         effective date of the Registration Statement, the Company notifies the
         Purchaser in writing of the existence of a Potential Material Event (as
         defined in Section 3(k) below), the Purchaser shall not offer or sell
         any Shares or engage in any other transaction involving or relating to
         Shares, from the time of the giving of notice with respect to a
         Potential Material Event until the Purchaser receives written notice
         from the Company that such Potential Material Event either has been
         disclosed to the public or no longer constitutes a Potential Material
         Event (the "Suspension Period"). Notwithstanding anything herein to the
         contrary, if a Suspension Period occurs and continues for a period of
         more than 1 Trading Day, at any time during any period commencing on a
         Trading Day a Draw Down Notice is deemed delivered and ending ten (10)
         Trading Days following the end of the corresponding Draw Down Pricing
         Period, then the Company must compensate the Purchaser for any net
         decline in the market value of any Shares purchased, or committed to be
         purchased, by the Purchaser pursuant to such recent Draw Down Pricing
         Period through the end of such Suspension Period. Net decline shall be
         calculated as the difference between the highest VWAP during the
         applicable Suspension Period and the VWAP on the Trading Day
         immediately following a properly delivered notice to the Purchaser that
         such Suspension Period has ended. If a Potential Material Event shall
         occur prior to the date the Registration Statement is filed, then the
         Company's obligation to file the Registration Statement shall be
         delayed without penalty for not more than thirty (30) calendar days.
         SUBJECT TO ANY FEDERAL OR STATE SECURITIES LAWS, REGULATIONS OR RULES,
         THE COMPANY MUST GIVE PURCHASER NOTICE IN WRITING OF THE EXISTENCE OF A
         POTENTIAL MATERIAL EVENT PROMPTLY UPON KNOWLEDGE THAT SUCH AN EVENT
         EXISTS AND, WHERE POSSIBLE, AT LEAST TWO (2) DAYS PRIOR TO THE FIRST
         DAY OF A SUSPENSION PERIOD, IF LAWFUL TO DO SO.

                           (k) "Potential Material Event" means any of the
         following: (i) the possession by the Company of material information
         that is not ripe for disclosure in a registration statement, as
         determined in good faith by the Chief Executive Officer or the Board of
         Directors of the Company or that disclosure of such information in the
         Registration Statement would be detrimental to the business and affairs
         of the Company; (ii) any material engagement or activity by the Company
         which would, in the good faith determination of the Chief Executive
         Officer or the Board of Directors of the Company, be adversely affected
         by disclosure in a registration statement at such time, which
         determination shall be accompanied by a good faith determination by the
         Chief Executive Officer or the Board of Directors of the Company that
         the Registration Statement would be materially misleading absent the
         inclusion of such information, or (iii) pursuant to applicable law, the
         Company must file a post-effective amendment to the Registration
         Statement because the Company experiences a fundamental change, must
         change the plan of distribution to the Prospectus, or must update the
         information included in the Prospectus pursuant to Section 10(a)(3) of
         the Securities Act.

                  Section 4. Cooperation with Company. The Purchaser will
cooperate with the Company in all respects in connection with this Agreement,
including timely supplying all information reasonably requested by the Company
(which shall include all information regarding the Purchaser and proposed manner
of sale of the Registrable Securities required to be disclosed


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in the Registration Statement) and executing and returning all documents
reasonably requested in connection with the registration and sale of the
Registrable Securities and entering into and performing its obligations under
any underwriting agreement, if the offering is an underwritten offering, in
usual and customary form, with the managing underwriter or underwriters of such
underwritten offering. The Purchaser shall consent to be named as an underwriter
in the Registration Statement. The Purchaser acknowledges that in accordance
with current Commission policy, the Purchaser will be named as the underwriter
of the Shares in the Registration Statement.

                  Section 5. Registration Procedures. Subject to federal and
state securities laws, rules and regulations, if and whenever the Company is
required by any of the provisions of this Agreement to effect the registration
of any of the Registrable Securities under the Securities Act, the Company shall
(except as otherwise provided in this Agreement), as expeditiously as possible,
subject to the Purchaser's assistance and cooperation as reasonably required:

                           (a)(i) prepare and file with the Commission such
         amendments and supplements to the Registration Statement and the
         Prospectus as may be necessary to keep such registration statement
         effective and to comply with the provisions of the Securities Act with
         respect to the sale or other disposition of all securities covered by
         such registration statement whenever the Purchaser of such Registrable
         Securities shall desire to sell or otherwise dispose of the same
         (including prospectus supplements with respect to the sales of
         securities from time to time in connection with a registration
         statement pursuant to Rule 415 promulgated under the Securities Act)
         and (ii) take all lawful action such that each of (A) the Registration
         Statement and any amendment thereto does not, when it becomes
         effective, contain an untrue statement of a material fact or omit to
         state a material fact required to be stated therein or necessary to
         make the statements therein, in light of the circumstances under which
         they were made, not misleading and (B) the Prospectus, and any
         amendment or supplement thereto, does not at any time during the
         Effectiveness Period include an untrue statement of a material fact or
         omit to state a material fact required to be stated therein or
         necessary to make the statements therein, in light of the circumstances
         under which they were made, not misleading;

                           (b)(i) prior to the filing with the Commission of
         any Registration Statement (including any amendments thereto) and the
         distribution or delivery of the Prospectus (including any supplements
         thereto), provide draft copies thereof to the Purchaser and reflect in
         such documents all such comments as the Purchaser (and its counsel)
         reasonably may propose and (ii) furnish to the Purchaser such numbers
         of copies of the Prospectus including a preliminary prospectus or any
         amendment or supplement to the Prospectus, as applicable, in conformity
         with the requirements of the Securities Act, and such other documents,
         as the Purchaser may reasonably request in order to facilitate the
         public sale or other disposition of the Registrable Securities;

                           (c) comply with the New York blue sky laws with
         respect to the Registrable Securities (subject to the limitations set
         forth in Section 3(g) above), and do any and all other acts and things
         which the Company determines to be reasonably


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         necessary or advisable to enable the Purchaser to consummate the public
         sale or other disposition in such jurisdiction of the Registrable
         Securities, except that the Company shall not for any such purpose be
         required to qualify to do business as a foreign corporation in any
         jurisdiction wherein it is not so qualified or to file therein any
         general consent to service of process;

                           (d) list such Registrable Securities on the Principal
         Market, and any other exchange on which the Common Stock of the Company
         is then listed, if the listing of such Registrable Securities is then
         permitted under the rules of such exchange or the Nasdaq Stock Market;

                           (e) notify the Purchaser at any time when the
         Prospectus is required to be delivered under the Securities Act, of the
         happening of any event of which it has knowledge as a result of which
         the Prospectus, as then in effect, includes an untrue statement of a
         material fact or omits to state a material fact required to be stated
         therein or necessary to make the statements therein not misleading in
         the light of the circumstances then existing, and the Company shall
         prepare and file a curative amendment or curative supplement under
         Section 5(a) as quickly as commercially possible and the period
         beginning on the date of notice until the curative amendment is
         effective or a curative supplement is filed shall be deemed a
         Suspension Period and the Company shall compensate the Purchaser as set
         forth in Section 3(j) herein;

                           (f) as promptly as practicable after becoming aware
         of such event, notify the Purchaser (or, in the event of an
         underwritten offering, the managing underwriters) of the issuance by
         the Commission or any state authority of any stop order or other
         suspension of the effectiveness of the Registration Statement at the
         earliest possible time and take all lawful action to effect the
         withdrawal, rescission or removal of such stop order or other
         suspension;

                           (g) take all such other lawful actions reasonably
         necessary to expedite and facilitate the disposition by the Purchaser
         of its Registrable Securities in accordance with the intended methods
         therefor provided in the Prospectus which are customary for issuers to
         perform under the circumstances;

                           (h) in the event of an underwritten offering,
         promptly include or incorporate in a prospectus supplement or
         post-effective amendment to the Registration Statement such information
         as the managing underwriters reasonably agree should be included
         therein and to which the Company does not reasonably object and make
         all required filings of such prospectus supplement or post-effective
         amendment as soon as practicable after it is notified of the matters to
         be included or incorporated in such prospectus supplement or
         post-effective amendment; and

                           (i) maintain a transfer agent for its Common Stock.

                  Section 6. Indemnification.


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                           (a) The Company agrees to indemnify and hold harmless
         the Purchaser and each person, if any, who controls the Purchaser
         within the meaning of the Securities Act ("Distributing Purchaser")
         against any losses, claims, damages or liabilities, joint or several
         (which shall, for all purposes of this Agreement, include, but not be
         limited to, all reasonable costs of defense and investigation and all
         reasonable attorneys' fees), to which the Distributing Purchaser may
         become subject, under the Securities Act or otherwise, insofar as such
         losses, claims, damages or liabilities (or actions in respect thereof)
         arise out of or are based upon any untrue statement or alleged untrue
         statement of any material fact contained in the Registration Statement,
         or any related preliminary prospectus, the Prospectus or amendment or
         supplement thereto, or arise out of or are based upon the omission or
         alleged omission to state therein a material fact required to be stated
         therein or necessary to make the statements therein in light of the
         circumstances when made not misleading; provided, however, that the
         Company will not be liable in any such case to the extent that any such
         loss, claim, damage or liability arises out of or is based upon an
         untrue statement or alleged untrue statement or omission or alleged
         omission made in the Registration Statement, preliminary prospectus,
         the Prospectus or amendment or supplement thereto in reliance upon, and
         in conformity with, written information furnished to the Company by the
         Distributing Purchaser specifically for use in the preparation thereof.
         This Section 6(a) shall not inure to the benefit of any Distributing
         Purchaser with respect to any person asserting such loss, claim, damage
         or liability who purchased the Registrable Securities which are the
         subject thereof if the Distributing Purchaser failed to send or give a
         copy of the Prospectus to such person at or prior to the written
         confirmation to such person of the sale of such Registrable Securities,
         where the Distributing Purchaser was obligated to do so under the
         Securities Act or the rules and regulations promulgated thereunder.
         This indemnity agreement will be in addition to any liability which the
         Company may otherwise have.

                           (b) Each Distributing Purchaser agrees that it will
         indemnify and hold harmless the Company, and each officer, director of
         the Company or person, if any, who controls the Company within the
         meaning of the Securities Act, against any losses, claims, damages or
         liabilities (which shall, for all purposes of this Agreement, include,
         but not be limited to, all reasonable costs of defense and
         investigation and all reasonable attorneys' fees) to which the Company
         or any such officer, director or controlling person may become subject
         under the Securities Act or otherwise, insofar as such losses, claims,
         damages or liabilities (or actions in respect thereof) arise out of or
         are based upon any untrue statement or alleged untrue statement of any
         material fact contained in the Registration Statement, or any related
         preliminary prospectus, the Prospectus or amendment or supplement
         thereto, or arise out of or are based upon the omission or the alleged
         omission to state therein a material fact required to be stated therein
         or necessary to make the statements therein not misleading, but in each
         case only to the extent that such untrue statement or alleged untrue
         statement or omission or alleged omission was made in the Registration
         Statement, preliminary prospectus, the Prospectus or amendment or
         supplement thereto in reliance upon, and in conformity with, written
         information furnished to the Company by such Distributing Purchaser
         specifically for use in the preparation thereof. This indemnity
         agreement will be in addition to any liability which


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         the Distributing Purchaser may otherwise have. Notwithstanding anything
         to the contrary herein, the Distributing Purchaser shall not be liable
         under this Section 6(b) for any amount in excess of the net proceeds to
         such Distributing Purchaser as a result of the sale of Registrable
         Securities pursuant to the Registration Statement.

                           (c) Promptly after receipt by an indemnified party
         under this Section 6 of notice of the commencement of any action, such
         indemnified party will, if a claim in respect thereof is to be made
         against the indemnifying party under this Section 6, notify the
         indemnifying party of the commencement thereof; but the omission so to
         notify the indemnifying party will not relieve the indemnifying party
         from any liability which it may have to any indemnified party except to
         the extent of actual prejudice demonstrated by the indemnifying party.
         In case any such action is brought against any indemnified party, and
         it notifies the indemnifying party of the commencement thereof, the
         indemnifying party will be entitled to participate in, and, to the
         extent that it may wish, jointly with any other indemnifying party
         similarly notified, assume the defense thereof, subject to the
         provisions herein stated and after notice from the indemnifying party
         to such indemnified party of its election so to assume the defense
         thereof, the indemnifying party will not be liable to such indemnified
         party under this Section 6 for any legal or other expenses subsequently
         incurred by such indemnified party in connection with the defense
         thereof other than reasonable costs of investigation, unless the
         indemnifying party shall not pursue the action to its final conclusion.
         The indemnified party shall have the right to employ separate counsel
         in any such action and to participate in the defense thereof, but the
         fees and expenses of such counsel shall not be at the expense of the
         indemnifying party if the indemnifying party has assumed the defense of
         the action with counsel reasonably satisfactory to the indemnified
         party; provided that if the indemnified party is the Distributing
         Purchaser, the fees and expenses of such counsel shall be at the
         expense of the indemnifying party if (i) the employment of such counsel
         has been specifically authorized in writing by the indemnifying party,
         or (ii) the named parties to any such action (including any impleaded
         parties) include both the Distributing Purchaser and the indemnifying
         party and the Distributing Purchaser shall have been advised by such
         counsel in writing that there may be one or more legal defenses
         available to the indemnifying party different from or in conflict with
         any legal defenses which may be available to the Distributing Purchaser
         (in which case the indemnifying party shall not have the right to
         assume the defense of such action on behalf of the Distributing
         Purchaser, it being understood, however, that the indemnifying party
         shall, in connection with any one such action or separate but
         substantially similar or related actions in the same jurisdiction
         arising out of the same general allegations or circumstances, be liable
         only for the reasonable fees and expenses of one separate firm of
         attorneys for the Distributing Purchaser, which firm shall be
         designated in writing by the Distributing Purchaser and be approved by
         the indemnifying party). No settlement of any action against an
         indemnified party shall be made without the prior written consent of
         the indemnified party, which consent shall not be unreasonably
         withheld.

                  All fees and expenses of the indemnified party (including
reasonable costs of defense and investigation in a manner not inconsistent with
this Section and all reasonable attorneys' fees and expenses) shall be promptly
paid to the indemnified party, as incurred; within


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ten (10) Trading Days of written notice thereof to the indemnifying party;
provided, that the indemnifying party may require such indemnified party to
undertake to reimburse all such fees and expenses to the extent it is finally
judicially determined that such indemnified party is not entitled to
indemnification hereunder.

                  Section 7. Contribution. In order to provide for just and
equitable contribution under the Securities Act in any case in which (i) the
indemnified party makes a claim for indemnification pursuant to Section 6 hereof
but is judicially determined (by the entry of a final judgment or decree by a
court of competent jurisdiction and the expiration of time to appeal or the
denial of the last right of appeal) that such indemnification may not be
enforced in such case notwithstanding the fact that the express provisions of
Section 6 hereof provide for indemnification in such case, or (ii) contribution
under the Securities Act may be required on the part of any indemnified party,
then the Company and the applicable Distributing Purchaser shall contribute to
the aggregate losses, claims, damages or liabilities to which they may be
subject (which shall, for all purposes of this Agreement, include, but not be
limited to, all reasonable costs of defense and investigation and all reasonable
attorneys' fees), in either such case (after contribution from others) on the
basis of relative fault as well as any other relevant equitable considerations.
The relative fault shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Company on the one hand or the applicable Distributing Purchaser
on the other hand, and the parties' relative intent, knowledge, access to
information and opportunity to correct or prevent such statement or omission.
The Company and the Distributing Purchaser agree that it would not be just and
equitable if contribution pursuant to this Section 7 were determined by pro rata
allocation or by any other method of allocation which does not take account of
the equitable considerations referred to in this Section 7. The amount paid or
payable by an indemnified party as a result of the losses, claims, damages or
liabilities (or actions in respect thereof) referred to above in this Section 7
shall be deemed to include any legal or other expenses reasonably incurred by
such indemnified party in connection with investigating or defending any such
action or claim. No person guilty of fraudulent misrepresentation (within the
meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation.

                  Notwithstanding any other provision of this Section 7, in no
event shall any (i) Purchaser be required to undertake liability to any person
under this Section 7 for any amounts in excess of the dollar amount of the net
proceeds to be received by the Purchaser from the sale of the Purchaser's
Registrable Securities (after deducting any fees, discounts and commissions
applicable thereto) pursuant to any Registration Statement under which such
Registrable Securities are or were to be registered under the Securities Act and
(ii) underwriter be required to undertake liability to any person hereunder for
any amounts in excess of the aggregate discount, commission or other
compensation payable to such underwriter with respect to the Registrable
Securities underwritten by it and distributed pursuant to the Registration
Statement.

                  Section 8. Notices. All notices, demands, requests, consents,
approvals, and other communications required or permitted hereunder shall be in
writing and, unless otherwise specified herein, shall be delivered as set forth
in the Purchase Agreement.


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                  Section 9. Assignment. Neither this Agreement nor any rights
of the Purchaser or the Company hereunder may be assigned by either party to any
other person. Notwithstanding the foregoing, (a) the provisions of this
Agreement shall inure to the benefit of, and be enforceable by, any transferee
of any of the Common Stock purchased by the Purchaser pursuant to the Purchase
Agreement other than through open-market sales, and (b) upon the prior written
consent of the Company, which consent shall not be unreasonably withheld or
delayed in the case of an assignment to an affiliate of the Purchaser, the
Purchaser's interest in this Agreement may be assigned at any time, in whole or
in part, to any other person or entity (including any affiliate of the
Purchaser) who agrees to be bound hereby.

                  Section 10. Counterparts/Facsimile. This Agreement may be
executed in two or more counterparts, each of which shall constitute an
original, but all of which, when together shall constitute but one and the same
instrument, and shall become effective when one or more counterparts have been
signed by each party hereto and delivered to the other party. In lieu of the
original, a facsimile transmission or copy of the original shall be as effective
and enforceable as the original.

                  Section 11. Remedies and Severability. The remedies provided
in this Agreement are cumulative and not exclusive of any remedies provided by
law. If any term, provision, covenant or restriction of this Agreement is held
by a board of arbitration or a court of competent jurisdiction to be invalid,
illegal, void or unenforceable, the remainder of the terms, provisions,
covenants and restrictions set forth herein shall remain in full force and
effect and shall in no way be affected, impaired or invalidated, and the parties
hereto shall use their best efforts to find and employ an alternative means to
achieve the same or substantially the same result as that contemplated by such
term, provision, covenant or restriction. It is hereby stipulated and declared
to be the intention of the parties that they would have executed the remaining
terms, provisions, covenants and restrictions without including any of those
that may be hereafter declared invalid, illegal, void or unenforceable.

                  Section 12. Conflicting Agreements. The Company shall not
enter into any agreement with respect to its securities that is inconsistent
with the rights granted to the purchasers of Registrable Securities in this
Agreement or otherwise prevents the Company from complying with all of its
obligations hereunder.

                  Section 13. Headings. The headings in this Agreement are for
reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

                  Section 14. Governing Law. This Agreement shall be governed by
and construed in accordance with the laws of the State of New York applicable to
contracts made in New York by persons domiciled in New York City and without
regard to its principles of conflicts of laws. Any action may be brought as set
forth in the Purchase Agreement. The Company and the Purchaser agree to submit
themselves to the in personam jurisdiction of the state and federal courts
situated within the Southern District of the State of New York with regard to
any controversy arising out of or relating to this Agreement. Any party shall
have the right to seek injunctive relief from any court of competent
jurisdiction in any case where such relief is available. Any dispute under this
Agreement shall be submitted to arbitration under the American Arbitration


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Association (the "AAA") in New York City, New York, and shall be finally and
conclusively determined by the decision of a board of arbitration consisting of
three (3) members (hereinafter referred to as the "Board of Arbitration")
selected as according to the rules governing the AAA. The Board of Arbitration
shall meet on consecutive business days in New York City, New York, and shall
reach and render a decision in writing (concurred in by a majority of the
members of the Board of Arbitration) with respect to the amount, if any, which
the losing party is required to pay to the other party in respect of a claim
filed. In connection with rendering its decisions, the Board of Arbitration
shall adopt and follow the laws of the State of New York. To the extent
practical, decisions of the Board of Arbitration shall be rendered no more than
thirty (30) calendar days following commencement of proceedings with respect
thereto. The Board of Arbitration shall cause its written decision to be
delivered to all parties involved in the dispute. The Board of Arbitration shall
be authorized and is directed to enter a default judgment against any party
refusing to participate in the arbitration proceeding within thirty days of any
deadline for such participation. Any decision made by the Board of Arbitration
(either prior to or after the expiration of such thirty (30) calendar day
period) shall be final, binding and conclusive on the parties to the dispute,
and entitled to be enforced to the fullest extent permitted by law and entered
in any court of competent jurisdiction. The prevailing party shall be awarded
its costs, including attorneys' fees, from the non-prevailing party as part of
the arbitration award. Any party shall have the right to seek injunctive relief
from any court of competent jurisdiction in any case where such relief is
available. The prevailing party in such injunctive action shall be awarded its
costs, including attorney's fees, from the non-prevailing party.

                            [SIGNATURE PAGE FOLLOWS]


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      [SIGNATURE PAGE TO REGISTRATION RIGHTS REGISTRATION RIGHTS AGREEMENT]


                  IN WITNESS WHEREOF, the parties hereto have caused this
Registration Rights Agreement to be duly executed, on this 14th day of May, 2001

                                            NATIONAL SCIENTIFIC CORPORATION



                                            By:          /s/ L.L. Ross
                                               ---------------------------------
                                                  L.L. Ross, President & CEO

                                            CORIANDER ENTERPRISES LIMITED



                                            By:         /s/ David Sims
                                               ---------------------------------
                                                  Name: David Sims
                                                  Title: Director


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