This is the first occasion on which I am able to make public the results of one of the pieces of research work on which I have been engaged during the past three years; it therefore seems to be an opportune moment for placing on record, side by side with the results, the forms of assistance to me which enabled those results to be obtained. I am anxious to do this as I have been ploughing a lonely furrow, and I would like to see the kind of help which I have received widely extended, so that the vast field of research may soon be scored by a number of single furrows; if the powers that be are far-sighted enough to give this help, I believe that from these furrows will spring a harvest of no small value, even when compared with the products of the great Government and trade efforts.