870. Restrictions on alienation.

An absolute interest in personalty no less than in realty, once given, cannot be fettered by a gift over on alienation1, for the right of alienation is incidental to the beneficial ownership of property2. Accordingly any restriction which substantially takes away the power of alienation is void as being repugnant to the very conception of ownership. A partial restraint which does not deprive the owner of his power of alienation may, however, be good3. Thus a condition that the donee is not to alienate a reversionary interest before it falls into possession4, or is not to alienate to a