A bill to constitute a public fund, upon which donations to charitable and other good uses in mortmain may be invested; and to impower all bodies politic and corporate, and trustees of charites, to invest the same, and to sell and dispose of all or any part of the lands, tenements, and hereditaments, in trust, for charitable uses, if they think fit; and to invest the produce in the purchase of some of the government transferrable securities, at three per centum per annum, in order that the same may be annihilated, and in lieu thereof, an annuity out of the said public fund may be paid and applied to the same charitable uses to which the lands, tenements, and hereditaments, are appropriated