September 25, 1934
Dr. Warren Weaver,
September 25, 1934
The Rockefeller Foundation
49 West 49th Street, New York
I am planning to apply to the Rockefeller Foundation for a grant for the continuation
of my researches. Will you come to Pasadena again this fall, and if you do, should
I delay making application until after your visit? If not, when should the application
be submitted?
The progress of our work during this year has been thoroughly satisfactory. The work
has consisted of almost entirely of the development of methods of attack on difficult
structural problems such as occur in biochemistry. The quantum-mechanical methods
which we developed and applied in the discussion of aromatic hydrocarbons and free
radicals have been extended and are now being applied to the porphyrins, the characteristic
constituents of haemoglobin and chlorophyll; our results indicate strongly that incorrect
formulas have been assigned to some of these substances by all investigators. The
study of the porphyrins requires an accurate knowledge of the configuration of the
pyrrole ring and of the effect of conjugation on interatomic distances. We have obtained
this information by the use of the electron-diffraction method, which we have developed
and tested until it rivals the spectroscopic method (applicable only to very simple
molecules) in accuracy. Moreover, we have discovered a new x-ray method, dependent
on anomalous dispersion, by means of which the environment of an iron atom in haemin
and related substances can be investigated. I believe that this is the most powerful
and promising method of attack on the problem of the structure of haemoglobin and
related substances that exists, and I should like very much to carry out the investigation
of a number of substances such as haemin, various haemochromogens, etc. The method
is laborious, however, requiring very accurate measurements (fortunately we have the
apparatus) and extensive calculations. I believe that we should have associated with
us next year a young man especially trained in haemoglobin work, to prepare the substances
and assist on the chemical side – I have written President Conant for advice regarding
the choice of this man.
In order to carry on an intensive attack on the haemoglobin problem, I have been contemplating
applying to you for a larger grant for next year than our present one of ten thousand
dollars annually. The only alternative would be to cut down on the more fundamental
investigations. I feel that this would be very short-sighted, inasmuch as nearly all
of the methods we plan to apply to the haemoglobin problem have been developed during
the last three years, and we can count on discovering others by continuing the fundamental
work on simpler substances. What is your advice regarding this?
My wife and I are hoping that you will visit Pasadena again, and that we can entertain
you at dinner.
Very Sincerely Yours,
Linus Pauling
