Section 3. Use of educational funds by religious schools; exemption of school property from taxation

No portion of any fund now existing, or which may hereafter be appropriated, or raised by tax, for educational purposes, shall be appropriated to, or used by, or in aid of any sectarian, church or denominational school; provided, that all real or personal property used for school purposes, where the tuition is free, shall be exempt from taxation and assessment for public purposes.