Section 6. A director, treasurer or other officer or agent of any such company who knowingly votes to authorize the issue of, or knowingly signs, certifies or issues, stock or bonds contrary to section four, or who knowingly votes to authorize the application, or knowingly applies the proceeds, of such stock or bonds contrary to said section, or who knowingly votes to assume or incur, or knowingly assumes or incurs in the name or behalf of such corporation, any debt or liability except for the legitimate purposes of the corporation shall be punished by a fine of not more than one thousand dollars or by imprisonment for not more than one year, or both.