Exhibit 3.1

Amendments to By-Laws of Cabot Corporation
Adopted March 14, 2008

1. Section 7.1 was amended to read as follows:

“7.1 Stock Certificates. The shares of capital stock of the corporation shall be represented by certificates, provided that the board of directors may provide by resolution or resolutions that some or all of any or all classes or series of stock shall be uncertificated shares. Any such resolution shall not apply to shares represented by a certificate until such certificate is surrendered to the corporation. Every holder of stock represented by certificates shall be entitled to a certificate stating the number and the class and the designation of the series, if any, of the shares held by him or her, in such form as shall, in conformity to law, the certificate of incorporation and the by-laws, be prescribed from time to time by the board of directors. Such certificate shall be signed by the chairman or vice chairman of the board, if any, or the president or a vice president and by the treasurer or an assistant treasurer or by the secretary or an assistant secretary. Any of or all the signatures on the certificate may be a facsimile. In case an officer, transfer agent, or registrar who has signed or whose facsimile signature has been placed on such certificate shall have ceased to be such officer, transfer agent, or registrar before such certificate is issued, it may be issued by the corporation with the same effect as if he or she were such officer, transfer agent, or registrar at the time of its issue.”

2. Section 8.1 was amended to read as follows:

“8.1 Transfer on Books. Subject to the restrictions, if any, stated or noted on the stock certificate, or otherwise in force, shares of stock may be transferred on the books of the corporation by the surrender to the corporation or its transfer agent of the certificate therefor properly endorsed or accompanied by a written assignment and power of attorney properly executed, with necessary transfer stamps affixed, and with such proof of the authenticity of signature as the board of directors or the transfer agent of the corporation may reasonably require. Uncertificated shares of stock may be transferred on the books of the corporation upon receipt of proper transfer instructions from the registered owner of the uncertificated shares, an instruction from an approved source duly authorized by such owner or from an attorney lawfully constituted. Except as may be otherwise required by law, by the certificate of incorporation or by these by-laws, the corporation shall be entitled to treat the record holder of stock as shown on its books as the owner of such stock for all purposes, including the payment of dividends and the right to receive notice and to vote or to give any consent with respect thereto and to be held liable for such calls and assessments, if any, as may lawfully be made thereon, regardless of any transfer, pledge or other disposition of such stock until the shares have been properly transferred on the books of the corporation.”