First came oxen and sheep, which according to their age and sex bore definite relations to each other, and by which all other values were measured. From an early period (at least 1000 B.C.) copper was in use, not yet however weighed, but estimated by the bulk, as I have already described. Side by side with it ingots of gold and silver passed from hand to hand. Such ingots are mentioned by Varro under the name of _bricks_ (_lateres_)[440]. Though this mention refers to a later period, we can yet infer from it with certainty that the practice of trafficking in small ingots of gold and silver prevailed in Italy as elsewhere. With gold came the art of weighing, which was also applied to silver. We have given reasons for believing that the weight-unit employed was the same as that which I have termed the ox-unit. We found the Etruscans, the close neighbours of the Romans, and who had access to the gold fields of Upper Italy, employing this unit as their standard from the commencement of their coinage in the 5th century for both gold and silver. Any of the towns of Southern Italy which struck gold, such as Metapontum, coined on the same standard, which was likewise employed for silver, sometimes a little reduced, by many communities, such as Tarentum. The standard ingot of gold would bear a known relation to that of silver, to the bar of bronze, the cow, and the sheep. We have given absolute proof of the relation between cattle and bronze in the 5th cent. B.C., and we may well infer similar constant relations between cattle and bronze, and the other metals. With greater exactness in commercial dealings the bronze rod was next weighed by the standard already in use for gold, and it was found that each of the 12 parts or unciae into which it was divided weighed just three times the ox-unit, that is, the weight of the small talent which we have found likewise in Macedon, Sicily, and Lower Italy, and which may have itself represented originally the conventional value of a slave, which was three cows among the Celts, the close kinsfolk of the Italians, and probably about the same among the early Greeks. As soon as the rods or _asses_ were exchanged by weighing, they would quickly lose their original form, which was only required so long as it was necessary that they should be of certain fixed dimensions. Under the new system it mattered not whether an _as_ was ·8 inches long, and three inches thick, provided only it was of full weight when placed in the scale. These are the pieces which are known as _aes rude_; as yet they are mere lumps of metal, without any stamp or device. Gaius well describes this stage: “For this reason bronze and the balance are employed (in _mancipatio_) because formerly they only employed bronze coins, and there were bars (_asses_), double bars (_dupondii_), half-bars (_semisses_) and quarters (_quadrantes_), nor was there any gold or silver coin in use, as we can