(6) This section shall have effect (a) in relation to any shares or debentures agreed to be taken by a person under writing an offer thereof by a prospectus, as if he had applied therefore in pursuance of the prospectus; and (b) in relation to a prospectus offering shares for sale, with the following modifications, namely (i) reference to sale shall be substituted for references to allotment; (ii) the persons by whom the offer is made, and not the company, shall be liable under sub section (2) to repay money received from applicants, and references to the company 's liability under that sub section shall be construed accordingly; and (iii) for the reference in sub section (3) to the company and every officer of the company who is in default, there shall be substituted a reference to any person by or through whom the offer is made and who is knowingly guilty of, or wilfully authorises or permits, the default.