As to the succession of the two metals, bronze and iron, among the ancient Egyptians, there is a considerable diversity of opinion among those who have studied the subject. Sir Gardner Wilkinson,[16] judging mainly from pictorial representations, thinks that the Egyptians of an early Pharaonic age were acquainted with the use of iron, and accounts for the extreme rarity of actual examples by the rapid decomposition of the metal in the nitrous soil of Egypt. M. Chabas,[17] the author of a valuable and interesting work upon primitive history, mainly as exhibited by Egyptian monuments, believes that the people of Egypt were acquainted with the use of iron from the dawn of their historic period, and upwards of 3000 years B.C. made use of it for all the purposes to which we now apply it, and even prescribed its oxide as a medicinal preparation. M. Mariette,[18] on the contrary, whose personal explorations entitle his opinion to great weight, is of opinion that the early Egyptians never really made use of iron, and seems to think that from some mythological cause that metal was regarded as the bones of Typhon, and was the object of a certain repugnance. M. Chabas himself is, indeed, of opinion that iron was used with extreme reserve, and, so to speak, only in exceptional cases. This he considers to have been partly due to religious motives, and partly to the greater abundance of bronze, which the Egyptians well knew how to mix so as to give it a fine temper. From whatever cause, the discovery of iron or steel instruments among Egyptian antiquities is of extremely rare occurrence; and there are hardly any to which a date can be assigned with any approach to certainty. The most ancient appears to be a curved scimitar-like blade discovered by Belzoni beneath one of the Sphinxes of Karnak, and now in the British Museum.[19] Its date is stated to be about 600 B.C.[20] A wedge of iron appears, however, to have been found in a joint between the stones of the Great Pyramid.[21]