EXHIBIT 3 BARRINGER LABORATORIES, INC. 15000 WEST 6TH AVENUE GOLDEN, COLORADO 80401 TELEPHONE: (303) 277-1687 FACSIMILE: (303) 277-1689 TO: R. SCOTT ASEN J. FRANCIS LAVELLE FROM: J. GRAHAM RUSSELL, PRESIDENT BARRINGER LABORATORIES, INC. DATE: APRIL...

                                   EXHIBIT 3
                                       
                          XXXXXXXXX LABORATORIES, INC.
                             00000 XXXX 0XX XXXXXX
                             XXXXXX, XXXXXXXX 00000
                           TELEPHONE: (000) 000-0000
                           FACSIMILE: (000) 000-0000


TO:       R. XXXXX XXXX
          J. XXXXXXX XXXXXXX

FROM:     J. XXXXXX XXXXXXX, PRESIDENT
          XXXXXXXXX LABORATORIES, INC.

DATE:     APRIL 13, 1998

RE:       SUBSCRIPTION AGREEMENT

     Gentlemen:  Reference is made to the Subscription Agreements with 
Xxxxxxxxx Laboratories, Inc. (the "Company") that each of you has executed of 
even date herewith.  For good and valuable consideration consisting of $10.00 
and your execution of the Subscription Agreement, the Board of Directors of 
the Company has determined that it will reimburse you for your legal and 
related out of pocket expenses associated with investment in the shares, 
including costs associated with the draft four-year convertible notes, notes 
and registration statement that your counsel provided to the Company.

                              Very truly yours,

                              XXXXXXXXX LABORATORIES, INC.


                              By: /s/ J. Xxxxxx Xxxxxxx               
                                  --------------------------------------
                                  J. Xxxxxx Xxxxxxx, President




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