Section 39. The directors may from time to time assess upon each share such amounts, not exceeding in all one hundred dollars on a share, or the price fixed under section fifty of chapter one hundred and fifty-nine, as they think proper, and may direct the same to be paid to the treasurer, who shall give notice thereof to the subscribers. If a subscriber has made no payment upon his shares, the directors, thirty days after an assessment has become due, may declare them forfeited, and may transfer them to any responsible person who subscribes for them and pays the assessments then due. If a subscriber neglects, for thirty days after notice from the treasurer, to pay an assessment upon his shares, the directors may order the treasurer, after giving notice of the sale, to sell such shares by public auction to the highest bidder, and, upon the payment by him to the corporation of the unpaid assessments, of interest to the date of sale and of the charges of sale, the shares shall be transferred to him. If within thirty days after the sale the purchaser does not make said payment to the corporation, the sale shall be cancelled, and the subscriber shall be liable to the corporation for the unpaid assessments, interest thereon and charges of sale. If the amount so paid by the purchaser to the corporation is more than the amount for which the shares were sold, the subscriber shall be liable to the purchaser for the deficiency; if it is less, the purchaser shall be liable to the subscriber for the surplus.