6 October 1956

Dr. Linus Pauling, Jr.

3909 Round Top Drive

Honolulu, T.H.

Dear Linus:

I am greatly pleased to have received your letter of 26 September, and to know that I can count on an additional gift to the California Institute of Technology for support of my researches for a minimum of five years. The fund that you and Anita provided during the last year has been of extraordinarily great value to me; in particular, it has relieved me of a considerable pressure that I would have been under otherwise to obtain money for support of certain aspects of my work that are hard to include in the funds available. Please tell Anita too how greatly I appreciate this action that you and she are taking.

Our work on mental deficiency has started off well, but I have already had a surprise. One of my proposals was that we attempt to develop a test for phenylketonuric heterozygotes; I had in mind that a phenylalanine clearance test, involving injection into the blood stream of a standard amount of phenylalanine and determination of the phenylalanine level thereafter, would do the job. A recent issue of Lancet contains an abstract of a talk by another investigator, in which he reports that injection of phenylalanine in the parents of patients with phenylketonuria leads to the elimination of phenylalanine in the urine, whereas it does not in normal individuals. I think that we shall probably check this work-I am a bit skeptical about it, because I have thought that the heterozygotes would have about half as much active enzyme as normal individuals, and that this amount of active enzyme would be enough to keep phenylalanine or phenylpyruvic acid from appearing in the urine, although I have thought that an increased level of phenylalanine after injection of a sample of it might be observed. I suppose that some of the other investigations that we have had in mind will be undertaken by other people, too.

I enclose a copy of my letter to Dr. Halperin.

We now have nine people working more or less directly on our Ford Foundation project. Only four of them are on salaries paid from the Ford Foundation grant-we have used a larger amount this year for outfitting laboratories, buying equipment such as spectrophotometers and electrophoretic apparatus, etc., than will be spent in the following years. One of them is from Harvard Medical School and MGH; he is Dr. David Allen, who got his M.D. at Harvard a couple of years after you. He had a National Science Foundation Fellowship. He is working in the analysis of proteins for phenylalanine, with the idea of making these determinations about ten times more precisely than has been done before. Another is Dr. Dhar, from Lucknow, India. He is the director of the pharmacological section of the National Central Laboratory of India for Research on Drugs. He is here with his wife and boy, supported by a fellowship given by the Rockefeller Foundation. Another is Dr. Santamaria, from Naples. I think that his fellowship is a Smith-Mundt Fellowship, perhaps also supplemented by a grant from the Italian Government. He is an M.D. too. I have another M.D. working with me, Dr. Oleg Jardetsky, who has a National Research Council Fellowship in the Medical Sciences. His wife, Dr. Christine Jardetsky, holds a fellowship from the American Cancer Society. Both of them are working on problems connected with enzyme chemistry, but they have expressed an interest in doing some work on the mental disease problem; in particular, if we can get some autopsy material they may attempt to isolate the enzyme that catalyzes the oxidation of phenylalanine to tyrosine.

Mama and I are disappointed that we shall not get to see you and the children soon, but we are looking forward to the visit to Honolulu a year from this Christmas. Mama, I think, has written to you that we shall be in Europe during most of next summer. We hope that you and the children can come to see us before then.

We are still very pleased with Deer Flat Ranch. We drove up last Thursday afternoon, and came home again Sunday morning-I was scheduled to give a talk at a meeting of the American Scandinavian Foundation in Los Angeles Sunday afternoon. On Friday and Saturday we watched the sea otters, flushed out several deer, dug a bit in the Indian shell mound in the hope of finding another soapstone olla, like the beautiful one, about fifteen inches in diameter, that had been dug up by Mr. Evans, with the skeleton of an Indian draped about it, clambered over the rocks of Salmon Cone, which is at the southwest edge of our place, talked about where we would build our new house, and in general had a good time. We got up before daybreak on Sunday, and passed eight deer during the first few miles of our trip home, one of them a nice buck with half a dozen points. Also, we were pleasantly surprised to have hundreds of monarch butterflies arrive, and settle down, apparently for the winter, on a few branches of one of the Monterey cypresses back of the house. I had thought that these butterflies all settled down for the winter in the grove of Monterey pines at Pacific Grove, 75 miles farther north.

Please give my love to Anita and the children. We hope that we shall see all of you before too many months go by.

Much love from

Daddy