February 24, 1944
Dr. J. D. Newburgh
3076 Geddes Avenue
Ana Arbor, Michigan
Dear Dr. Newburgh:
I was very much interested to see your calculation on the effect of hapten in increasing
antigen-antibody precipitation in the region of excess antibody, which Dr. Stitz gave
me when I was in Chicago.
I think that you are right in making this prediction; it may, however, be not easy
to verify it experimentally, because of the heterogeneity of antisera.
We have just carried out some experiments on the decrease in amount of precipitate
by increase in the amount of antibody, and I have asked Dr. Pressman to set up some
tubes with hapten present, in order to test your prediction. I trust that you will
let me know what you do about publishing your work, so that we may refer to it in
any appropriate place.
You will be interested to know, I am sure, that we have observed an increase in the
amount of precipitate on addition of heterologous haptens; thus the aliphatic acids
cause an increase of as much as fifty percent in the amount of precipitate formed
by antibenzoic acid serum and appropriate antigen. This effect is not, I think, the
effect which you are discussing, since it occurs over a wide range of relative values
of antibody and antigen. Although we have a large amount of experimental information
about the phenomenon, we have not yet succeeded in developing a reasonable explanation
of it.
I was pleased to read your paper on osmotic work of the kidney last year, when Dr.
Addis asked my opinion of it. I had some difficulty in checking your calculations,
mainly because I did not know what compositions you assumed for glomerular filtrate
and urine. I believe that I told Dr. Addis that your statement that the osmotic work
of the kidney reaches a minimum at a certain value of the urine volume holds only
in case that the amount of ingested salt is held constant, and that if the salt intake
is increased the osmotic work continues to decrease with increase in urine volume.
(I am relying on my memory for these statements.) I would be grateful to you for a
reprint of your paper, if you have an extra one.
If you see Brockway, tall him that I am hoping to stop in Ann Arbor some time, but
do not plan to make this visit very soon.
Sincerely yours,
Linus Pauling
