NAVY AIR MAIL
June 30, 1948
Dr. S. J. Singer
California Institute of Technology
Pasadena 4, California
Dear Dr. Singer:
I have just got worried about your manuscript. I haven't written to you because I have nothing much to say about the manuscript,
but it occurred to me that you might want the drawings back, and so I am returning them with the manuscript herewith.
I hope I haven't held the paper up.
I shall look forward to learning about the progress that you have made on the Rothen problem when I get back home, September
19. One idea that has occurred to me is that instead of using metal slides it might be possible to use thin sheets of mica,
perhaps treated with a uranium salt in order to make the protein stick. There is a paper by Polansky in a recent Nature, in which it is shown that layers of mica uniform to one half unit (10 Ǻ. Thickness) can be obtained by cleavage.
Also, I thought that perhaps some results could be got by coating the positive layer of protein with metal at a small angle
of inclination from one side. This ought to cover the one side of protein molecules, leaving the other side bare, and so perhaps
the slides treated in this way would still absorb nearly half of the antibody.
It will be a pleasure to talk with you about this work and other work that you might be interested to carry on.