The ounce seems to be the highest unit of weight, and just as in the Brehon Laws an unga of silver is equated to a cow, so in early times an unga of gold seems to have been the regular value of a slave, the most valuable of living chattels. At least we may so infer from a curious story of St Finnian of Clonard:
Life of St Finnian (of Clonard, Co. Meath).
(Book of Lismore, fol. 24 b, c.)
Tainic iar sin Finnen cu Cilldara co Brighit, cu m-bui ic tiachtuin leiginn ocus proicepta fri re. Ceilebrais iar sin do Brigit ocus dobreth Brighit fainne oir dho. Nir 'bho santach som imon saegul: ni roghabh in fainne. "Ce no optha," ar Brigit, "roricfea a leas." Tainic Finnen iar sin cu Fotharta Airbrech. Dorala uisce do. Roinnail a lamha asin usci[1]: tuc lais for a bhais asan uisci in fáinne targaidh Brighit dó.
Táinic iar sin Caisin, mac Naemain, co faelti moir fri Finden. Ocus coneadhbair fein dó ocus roacain fris ró Fotharta ic cuinghidh oir fair ar a shaeire. "Cia mét," ar Finnen, "conaidheas?" "Noghebhudh uingi n-oir," ar Caisin. Rothomthuis sé iar sin in fainne [ocus frith uingi oir[2]] ann. Dorat Caisin hi ar a shaeriri.
Translation.
"After that came Finnian to Kildare to Brigit and he was engaged in teaching and preaching for a time. He takes leave afterwards of Brigit and Brigit gave a ring of gold to him. He was not covetous regarding the world: he accepted not the ring. "Though thou refusest," said Brigit, "thou wilt require it." Finnian came after that to Fotharta Airbrech[3]. [On his way] he met water. He washed his hands with the water [and] brought on his palm from out the water the ring that Brigit offered to him.
After that came Caisin, son of Naeman, with great joy to [visit] Finnian. And he offered himself to him and complained to him that the king of Fotharta was demanding gold from him for his liberation. "How much," said Finnian, "asketh he?" "He would accept an ounce of gold," said Caisin. He [Finnian] weighed after that the ring (and there was found an ounce of gold[4]) in it. Caisin gave it for his liberation."I am indebted for this valuable reference, which also enables us to form an idea of the relative value of gold and silver in early Ireland, to the Rev. B. Mac Carthy, D.D., of Youghal.
But there is another weight called crosoch (crosóg or crosach), found in the most ancient poems. For instance in Cuchulaind the
