Back in the heyday of using trusts for shifting income, if a trust contained one of those powers, like the power of the grantor to withdraw property from thetrust and replace if with property of equal value, someone who thought thetrust was being used to shift income, would consider that power to be a defect.
The ancient artefact is also inset with an image of the goddess Venus, and lay forgotten in the library of the National Trustproperty for several years.