a surgeon's instrument, which, by pressing gently on the dura mater, causes an evacuation of the pus collected between the cranium and the membrane just mentioned, through the perforation made by the trepan.

DEDINGTON, a town of the hundred of Wootton, in Oxfordshire, sixty-nine miles from London, and seventeen from Oxford. In the neighbourhood are two medicinal springs. It has a market, which is held on Saturday. The inhabitants amounted in 1801 to 1172, in 1811 to 1296, in 1821 to 1404, and in 1831 to 1590.