Before any mutual savings bank shall be authorized to do business, its incorporators shall create a guaranty fund for the protection of its depositors against loss on its investments, whether arising from depreciation in the market value of its securities or otherwise:

(1) Such guaranty fund shall consist of payments in cash made by the original incorporators and of all sums credited thereto from the earnings of the savings bank as hereinafter required.

(2) The incorporators shall deposit to the credit of such savings bank in cash as an initial guaranty fund at least five thousand dollars.

(3) Prior to the liquidation of any such savings bank such guaranty fund shall not be in any manner encroached upon, except for losses and the repayment of contributions made by incorporators or trustees as hereinafter provided, until such fund together with undivided profits exceeds twenty-five percent of the amount due depositors.

(4) The amounts contributed to such guaranty fund by the incorporators or trustees shall not constitute a liability of the savings bank, except as hereinafter provided, and any loss sustained by the savings bank in excess of that portion of the guaranty fund created from earnings may be charged against such contributions pro rata.