Abstract A theory is presented which predicts the vacancy loss to fixed sinks during a quench. For quenches in which the temperature decreases linearly with time, the fraction of the vacancies lost is shown to depend only on the product D q T q, where D q is the vacancy diffusion coefficient at the quench temperature T q, and τq is the quench time. The theory is used to analyse the results of a series of quenches having values of T q and τq in the ranges 470°c < T q < 1030°c and 0·025 sec < τq < 4·3 sec. Both 0·016 in. and 0·002 in. diameter gold wires were studied and found to yield an effective formation energy of about 0·90 ev for the fastest quench times. For any value of the activation energy Q for self-diffusion in the neighbourhood of 1·8 ev, the quenching data are consistent with the theory only for one pair of values of E M and E F. With Q = 1·81 ± 0·02 ev it is found that E F = 0·98 ± 0·02 ev and E M = 0·83 ± 0·04 ev. The fact that the vacancy loss depends only on D q T qτq is confirmed over a r...