The practice apparently had already grown up of reckoning 12 of the silver tremisses as a solidus of silver, twenty of which went to the pound of 240 pence, without, however, any pretence being made that this solidus of twelve silver pence was to be reckoned as equal to the gold solidus in making payments.
In the ‘Capitulare Liftinense’ of A.D. 743[135] a payment is enacted de unaquaque cassata solidus, id est 12 denarii. It was necessary to make this explanation.
It is not known how much earlier the practice of reckoning in pounds of silver of 20 solidi of 12 denarii came into vogue, but it was long before the issue of the nova moneta.
It might at first sight be thought that these twelve denarii may have been twelve argentei or drachmæ, but 240 drachmæ would make far more than a pound. And by an edict of A.D. 765[136] Pippin had enacted that out of a pound of silver not more than 22 solidi were to be made, one of which was to go to the monetarius, and this clearly forbids the supposition that the solidus could be of twelve drachmæ. The pound would contain only eight such solidi.
Another Capitulare of A.D. 779[137] proves that the twelve denarii were Merovingian denarii of 28·8 wheat-grains.[138]
The issue of the new denarii of 32 wheat-grains was apparently made before A.D. 781, for in that year an edict was passed forbidding the currency of the old denarii.[139]
The pound of the nova moneta was 240 pence of 32 w.g. = 7680 w.g.
There was nothing very remarkable in this raising of the silver denarius from 28·8 to 32 wheat-grains. It was merely adopting the Imperial standard. But the extraordinary thing was that Charlemagne seems to have thought that he could, by law, substitute the solidus of 12 of his silver denarii for the gold solidus hitherto in use. The gold currency was going out and the silver currency was taking its place; but it was quite another thing to make the solidus of 12 silver denarii of 32 wheat-grains legal tender in the place of the gold solidus of the Lex Salica of 40 silver denarii of 28·8 wheat-grains. Yet this was what Charlemagne did, though perhaps only by degrees.
Charlemagne enacted that the silver solidus should be legal tender for the gold solidus.
The change was made under the pretence of the sanction of ancient custom. In the addition made to Tit. XXXVI. of the Ripuarian law the wording of the clause as to the payment of wergelds was ‘Quod si cum argento solvere contigerit, pro solido duodecim denarios, sicut antiquitus est constitutum.’ And this allusion to antiquity was repeated.