But towards the close of the Merovingian period came one of those strange monetary changes, so difficult to account for, which before long put an end altogether to the issue of these gold tremisses.
All through the Merovingian period payments had no doubt been made in silver as well as in gold, by weight, and during the later part of the period silver tremisses were issued of the same weight as the gold. And thus gradually, at first concurrently with the gold tremisses and at last driving them out, came into use a silver currency of 20 pence to the ounce and 240 to the Roman pound.
With this silver currency and the following of this weight system came in apparently the method of silver monetary reckoning, so familiar to us, of dividing the pound of 240 pence into 20 solidi or shillings of 12 pence—the pound being still the Roman pound of 6912 wheat-grains. This silver solidus was, however, only one of account and was never issued as a coin.
The nova moneta of Charlemagne.
Finally, just before Charlemagne assumed the title of Emperor another change was made by the issue of his nova moneta.
His pound of 240 silver tremisses of 32 wheat-grains, and silver solidus of account of 12 pence.
The silver currency had by this time become predominant, and in the capitularies the silver solidus of 12 pence had already come into use. Charlemagne, in issuing the nova moneta, made no alteration in the method of reckoning, except that he brought the weight of the silver tremissis or penny back again to the Imperial standard of 32 wheat-grains, thus making his pound of 240 of the new pence 7680 wheat-grains instead of 6912 and the ounce 640 instead of 576.
At the same time we shall find that he tried, by making his nova moneta legal tender, to force the new silver solidus of 12 pence into use as equivalent, in payments, for the gold solidus of three gold tremisses, which up to that time had been the solidus of the Salic laws.
Made legal tender at a ratio of 1:4 with gold.