On the evening of your Wistar Party I am due in Paris to keep an engagement intimately bound up with the work of the Foundation. More than ten years ago I saw that if I was going to solve the problem I began with, I would have to ban social engagements of all kinds and stick to my purpose. I know that in doing that I have lost much pleasure and benefit, even though I have found considerable compensation in the work which made such sacrifices necessary.
