By express words, or testament, when it is declared by him in his lifetime, viva voce, or by writing, as the first emperors of Rome declared who should be their heirs. For the word heir does not of itself imply the children, or nearest kindred of a man; but whomsoever a man shall anyway declare he would have to succeed him in his estate. If therefore a monarch declare expressly, that such a man shall be his heir, either by word or writing, then is that man immediately after the decease of his predecessor, invested in the right of being monarch.