721.—The following instruments shall be exempt from stamp duty:—

(a) Any instruments used for carrying into effect the First Part of this Act: and

(b) Any instruments used by or under the direction of the Board of Trade in carrying into effect the Second, Fifth, Eleventh, and Twelfth Parts of this Act; and

(c) Any instruments which are by those Parts of this Act required to be in a form approved by the Board of Trade, if made in that form.