There is still one element in this matter which we must not overlook. A certain number of gold rings have been found in Egypt. Their unit is fixed by Lenormant at 8·1 grammes (128 grains). Brandis regarded them as Syrian in origin, and thus got rid of all difficulty. Others regard the rings as evidently of Egyptian manufacture, and from finding as they think a corresponding mina appearing in Egypt in Ptolemaic times regard this unit as a genuine ancient Egyptian standard in use long anterior to the Persian conquest. It may thus be very probable that the standard employed in early days in Egypt for gold (and also electrum and silver) was this unit of 128 grains, which is of course almost identical with an ox-unit. Silver, according to Erman[299], was in the time of the oldest Egyptian records more valuable than gold, for in enumeration it is always named before gold, whereas under the later dynasties it is named as with us always after gold, shewing that a great change had taken place in the relations between these metals. It is then clearly conceivable that at the outset one and the same unit of about 128-30 grains, under the name of kat, served as the unit for both gold and silver (which explains perfectly the fact that an ox is valued at a kat of silver), but that in after days when the change in the relative values of the metals came, there was found a need for a new silver unit, just as the Greeks in certain places found it necessary to form the Aeginetan and other standards, and the Babylonians found themselves compelled to form that standard which alone can with truth be termed _the Babylonian_, the silver unit of 172 grains.