The said emergency shall be deemed to have terminated whenever a resolution shall be duly enacted to the effect that the said emergency no longer exists; and thereupon the Department of Supplies shall proceed with the sale of the remaining stock on hand to the best advantage, selling the same at such prices as will, as near as may be, return to the city the actual costs and expenses involved in such transaction; and the amount received herefrom shall be returned to the city treasurer, to make restitution for the amounts theretofore appropriated for said purposes.