Section 19. Bonds issued by the Authority under the provisions of this chapter are hereby made securities in which all public officers and public bodies of the commonwealth and its political subdivisions, all insurance companies, trust companies, savings banks, co-operative banks, banking associations, investment companies, executors, administrators, trustees and other fiduciaries may properly and legally invest funds, including capital in their control or belonging to them. Such bonds are hereby made securities which may properly and legally be deposited with and received by any commonwealth or municipal officer or any agency or political subdivision of the commonwealth for any purpose for which the deposit of bonds or obligations of the commonwealth is now or may hereafter be authorized by law.