This paper gave details of a series of experiments made on the same iron wire as was used in experiments described in previous papers. This series was made on the wire after it had been heated to redness and allowed to cool. A linear relation was again found to hold between log. b and n, where b and n are the quantities (constant in any one experiment) symbolised in. the equation yn(x + a) = b, y being range of oscillation and x being number of oscillations of the wire which have taken place since the commencement of the experiment. It was further found that the line representing that relation passed (as did all other such lines previously obtained with this wire) through the point log. b = 2·3, n = 1. Thus the quantity provisionally called the Oscillation Constant in the preceding paper, and regarded as characteristic of the material of the wire, retains its old value even after the wire has been heated to redness.