(1) An act or instrument relating to the business of a firm, other than an incorporated limited partnership and done or executed in the firm-name, or in any other manner showing an intention to bind the firm, by any person authorised to bind the firm, whether a partner or not, is binding on the firm and all the partners.(2) An act or instrument relating to the business of an incorporated limited partnership, and done or executed in the name of the partnership, or in any other manner showing an intention to bind the firm, by any person authorised to bind the firm, whether a general partner or not, is (subject to section 14(3) ) binding on the partnership and all the general partners.(3) This section does not affect any general rule of law relating to the execution of deeds or negotiable instruments.