The Wealth of Nations by Part 5 Chapter 2 Page 133

It may, however, sometimes be otherwise with those children who, in the language of the Roman law, are said to be emancipated; in that of the Scotch law, to be forisfamiliated; that is, who have received their portion, have got families of their own, and are supported by funds separate and independent of those of their father.

Whatever part of his succession might come to such children would be a real addition to their fortune, and might therefore, perhaps, without more inconveniency than what attends all duties of this kind, be liable to some tax.

The casualties of the feudal law were taxes upon the transference of land, both from the dead to the living, and from the living to the living. In ancient times they constituted in every part of Europe one of the principal branches of the revenue of the crown.