All securities purchased under the authority of this Act shall be held for the benefit of the public agency which purchased them, and if purchased with money taken from a particular fund, such securities shall be credited to and deemed to be a part of such fund, and shall be held for the benefit thereof. All securities so purchased shall be deposited and held in a safe place by the person or persons having custody of the fund to which they are credited, and such person or persons are responsible upon his or their official bond or bonds for the safekeeping of all such securities. Any securities purchased by any such public agency under authority of this Act, may be sold at any time, at the then current market price thereof, by the governing authority of such public agency. Except as provided in Section 4.1 of “An Act in relation to State finance”, all payments received as principal or interest, or otherwise, derived from any such securities shall be credited to the public agency and to the fund by or for which such securities were purchased.