The primitive mode of circulating the metals, indeed, was simply that of buying and selling them against other commodities, the weights or portions being made rudely estimated. Some of the earliest specimens of money consist of the
aes rude, or rough, shapeless lumps of native copper employed as money by the ancient Etruscans. In the Museum of the Archiginnasio at Bologna may be seen the skeleton of an Etruscan, half embedded in earth, with the piece of rough copper yet within the grasp of the bony hand, placed there to meet the demands of Charon. Pliny, moreover, tells us that, before the time of Servius Tullius, copper was circulated in the rude state. Afterwards copper, brass, or iron were, it is probable, employed in the form of small bars or spikes, and the name of the Greek unit of value,
drachma, is supposed to have been derived from the fact that six of these metal spikes could be grasped in the hand, each piece being called an
obolus. Such is supposed to have been the first system of money which was passed purely by
tale, or number of pieces.