Experimentis cognitum est Barbaros malle Româ petere reges quam habere. These experiments are admirably represented in the invitation and expulsion of Vonones, (Annals ii. 1-3,) Tiridates, (Annals vi. 32-44,) and Meherdates, (Annals xi. 10, xii. 10-14.) The eye of Tacitus seems to have transpierced the camp of the Parthians and the walls of the harem.