Copy letter from Robert William Frederick Harrison, to Professor William Abbott Herdman, Fellow of the Royal Society Acknowledges Herdman's two letters with reference to Professor B Moore's paper on the action of acids and alkalis on the growth of Echinus esculentus. The course suggested in Herdman's second letter of adding a dated postscript will be a much simpler way of dealing with the matter, as the manuscript has been passed for printing and the illustrations have already been put in hand. 23 October 1905