Serrated Denarii are less than 5 percent of all Roman Republican Issues. And their production is certainly not consisten,t as the above timeline shows. In constructing it I’ve deferred mostly to Hersh & Walker and Mattingly, and noted Hollstein’s disagreements. Even if one prefers one dating assignment over the other the big pattern doesn’t change. A few early issues, most notably the Narbo issue, four issues in the midst of the Marian period when Roman was embattled against the Cimbri and the Teutoni, and then a big uptake around the time of Sulla’s return, followed by petering out over about the next two decades. Crawford held that it must be an aesthetic as it would not adequately deter forgeries. The awkward uneven execution makes it hard to consider it likely to have been an aesthetic choice.
Kraft et al. has undertaken a recent analysis:
A number of serrated silver denars of the Roman Republic and a Greek bronze coin were investigated, paying special attention to the notches, in order to reveal their production technique. Particular interest was devoted to three contemporary forgeries of serrated denars, because the ofﬁcial pure silver issues were also available for inspection. Several microbeam analytical techniques were applied, such as scanning electron microscopy(SEM), electron probe micro-analysis (EPMA) and secondary ion mass spectrometry(SIMS). The surfaces of the notches, which show traces of the tools used, were investigated by SEM. In the case of the forged coins, the thickness of the silver layer (inside the notches as well as on the surface of the coin) was determined by SEM and SIMS. The main components of the surfaces were similar in both cases as measured by EPMA. Combining the results, it is possible to reconstruct the steps in the production of the serrated denars. The investigations also permit a review of different opinions about the purpose of the notches.
Their conclusion is that forgers using the foil technique and the official mint both used the same technique: chiseling each notch into the blank prior to its heating and striking. AND, that it is likely that serrati were preferred because they where perceived as less likely to be forged. It would have been a costly labor intensive technique, so there must have been some perceived benefit. It is tempting to connect the height of their production with the monetary anxieties reflected in the legislation we talked about yesterday.
Tacitus tells us in the Germania:
Silver and gold the gods, I know not whether in their favor or anger, have denied to this country.  Not that I would assert that no veins of these metals are generated in Germany; for who has made the search? The possession of them is not coveted by these people as it is by us. Vessels of silver are indeed to be seen among them, which have been presented to their ambassadors and chiefs; but they are held in no higher estimation than earthenware. The borderers, however, set a value on gold and silver for the purpose of commerce, and have learned to distinguish several kinds of our coin, some of which they prefer to others: the remoter inhabitants continue the more simple and ancient usage of bartering commodities. The money preferred by the Germans is the old and well-known species, such as the Serrati and Bigati.  They are also better pleased with silver than gold;  not on account of any fondness for that metal, but because the smaller money is more convenient in their common and petty merchandise.
This testimony has certainly influenced our belief that these coins were more trusted. Even if they made up a small percentage of the coins in circulation they were certainly noticable, and would have been easy to select out in Imperial times as older, and perhaps purer than some contemporary issues.
Here is Duncan Jones‘ chart showing decreasing fineness:
However, can we tell is serrati were really preferred in a more contemporary context? For this we’d need hoard evidence. There is no hoard I have found where serrati make up even a majority of the coins, rarely even 10%. I’d need to do a proper statistical analysis of the hoards to see if they are retained in greater numbers than one might expect. Unfortunately I had some problems pulling the data from the CHRR online and I don’t absolutely need to find out to write the book, so I shall probably let it go for now.
The Italian scholarship is on ILL order. If it changes my thinking, I’m sure you’ll be the first to know.
Wondering what these things look like? Click Here.
What is interesting is that periodically we find a coin of an unserrated issue that has been serrated after it has entered circulation (in ancient times? in modern times?):
Was this a means of ‘adding value’ in someway?
Update 24 January 2014: Just for completeness, here is the English abstract of the Italian article from Bollettino di numismatica 17.1 nos.32-33 (Jan/Dec 1999): p.104-128. Pancotti and Calabria consider the consequences of these finding in the Proceedings of the XVIth International Numismatic Congress (2009), 888-892. They do not consider the work of Kraft et al. Likewise Kraft seems unaware of de Caro et al. A sad state of affairs.
The abstract is a little misleading. 250 coins were not looked at with SEM+EDS only 5 got the full treatment. The 250 is the number examined with an ‘ordinary’ (?) microscope. Here’s the data on the five that got the works:
In inexplicably they use E. R. CALEY, Analysis of Ancient Metals, Pergamon Press, Oxford 1964 for comparative data instead of Walker, D. R. (1980) The silver content of the Roman Republican coinage’, in D.M. Metcalf, W.M. Oddy (edd.) Metallurgy in numismatics, 1 (London), 55-72. Another missed opportunity.