Eyo (Iju), the dominant people on the Nun branch of the Niger delta, Gulf of Guinea; their territory extends west to Yorubaland, east to the Old Calabar river, and north to the Benin country, and their chief tribal divisions are the Akassa at the mouth of the Nun; the Nempe of Brass about the New Calabar river; and the Okrika of Bonny still farther west. The Nempe are the most active and powerful of these negro peoples, and their dialect has become the standard form of Eyo speech. It has been reduced to writing by the English missionaries, and now possesses an extensive religious literature; but most of the tribes are still nature worshippers, and even the nominal Christians continue to practise pagan rites. Amongst the local gods are monkeys, the shark (New Calabar), and the iguana (Bonny estuary). The "Jew-Jew men," or magicians, also retain much of their former influence as medicine men, priests, soothsayers, and judges. The ordeal by poison prevails, the essere, or Calabar bean (Physostigma venenosum), being much employed for this purpose. It was thus that the Europeans became acquainted with the potent properties of this plant, which is now found to be efficacious in the treatment of ophthalmia. All the Eyo tribes are keen traders, and the "Bonny men" especially enjoy a well-earned reputation for their shrewd business habits.