Section 31. The treasurer shall give notice of the time and place appointed for such sale, and of the amount due on each share, by advertising the same three weeks successively before the sale in a newspaper, published in the county where the corporation is established; and an assignment of the shares so sold, made by the treasurer and acknowledged before a justice of the peace and recorded in the books of the corporation, shall transfer said shares to the purchaser, who shall be entitled to a certificate therefor.