53 Pa. Stat. § 16475
It shall be lawful for said park commissioners to acquire title to the whole of any tract of land, part of which shall fall within the boundaries mentioned in the first section of this act, and to take conveyance thereof in the name of the city of Philadelphia; and such part thereof as shall lie beyond or without the said park limits, again to sell and convey in absolute fee-simple to any purchaser or purchasers thereof, by deeds to be signed by the mayor, under the seal of the city, to be affixed by direction of councils, either for cash, or part cash and part to be secured by bond and mortgage to the city, paying all cash into the city treasury. Provided, That the proceeds of such sales shall be paid into the sinking fund for the redemption of the loan created under the provisions of this act: Provided also, That no commissioner, nor any officer under the park commission, shall in anywise be directly interested in any such sale of lands by the commissioners as aforesaid; and if any commissioner or officer aforesaid shall act in violation of this proviso, he shall, if a commissioner, be subject to expulsion; if an officer, to be discharged by a majority of the votes of the board of park commissioners, after an opportunity afforded of explanation and defense.
53 P.S. § 16475