Pending use for the purpose for which received, each hospital authority created by and under this article is authorized and empowered to invest all moneys or any part thereof received through the issuance and sale of revenue certificates of the authority in any securities which are legal investments or which are provided for in the trust indenture securing such certificates or other legal investments; provided, however, that such investments will be used at all times while held, or upon sale, for the purposes for which the money was originally received and no other. Contributions or gifts received by any authority shall be invested as provided by the terms of the contribution or gift or in the absence thereof as determined by the authority.