In the mid-1st century, Rome was trading one amphora of this for one slave from Gaul
turned to the use of a 
... sufficiency; by the mid-second century, Dressel 2-4 production had declined to 
.... in Rome, and published, amongst other observed amphora types, in CIL XV, 
...... availability of slave labour resulting from the Punic Wars and trade with Gaul.