brooch of Queen Medbh, "My spear brooch of gold which weighs thirty ungas, and thirty half ungas, and thirty crossachs and thirty quarter [crossachs]." (O'Curry, Manners and Customs, Vol. III. p. 102.) The weight of a crosoch we learn from a gloss quoted by O'Donovan (Supplement to O'Reilly's Dictionary) from MS. R. I. A., No. 35, 5. 49.
da pinginn agas cetrime pinginne isin lacht caerach i, crosóg[1].
"Two pinginns and a fourth of a pinginn are a milk of a sheep,
i.e. a crosog." Since 1 pinginn = 8 grs. wheat therefore a crosóg =
18 grs. wheat or 13·5 grs. Troy.
There are accordingly 32 crosochs in the unga of the Brehon Laws.
Inspection at once shows that the crosoch must have belonged to a different system, on which either the system of ungas and screapalls was grafted or vice versa. The expulsion of the crosoch from the later Irish shows that the first alternative is the true one.
Again, it is certain that the unga and screapall were borrowed from the Roman system, probably before the time of Constantine, as after his time the solidus became universal throughout the Empire, and has left its impress everywhere.
The crosoch therefore must be non-Roman, i.e. belong to the native population.
Above we saw that it was used along with ungas and half ungas in describing Medbh's Fibula. Here is historical evidence of its use in the weighing of gold ornaments.
There were certainly 32 crosochs in the ounce of the Brehon Laws, but if we can show in another system of north-western Europe a weight exactly the same as the crosoch, with an ounce which is its thirty-fold, we may hesitate to lay down that the full Roman ounce with its 432 grs. Troy (576 grs. wheat) was the earliest form of Irish unga.
There is no mention of screapalls in the weight of Medbh's brooch. It is quite possible that under ecclesiastical influences the full Roman ounce and its division into screapalls may have been introduced at a comparatively late period. The contact between Kelts and Scandinavians in early times has of late excited much interest.
- ↑ O'Donovan has omitted caerach of the MS.