STANFORD UNIVERSITY
MEDICAL CENTER
PALO ALTO, CALIFORNIA

DEPARTMENT OF GENETICS June 28, 1961 DAvenport 1200
School of Medicine Cables STANMED

Or. Torbjorn Caspersson
Karolinska Institut
Stockholm, Sweden

Dear Torbjorn:

As | understood that you were eager to have a confirmation of your plans
before July 1, | cabled you today, and hope that this was In good time for you.
We are most interested to enlist your cooperation In some of the analytical
and design problems; and, as | Indicated in the cable can reserve £5000In
the budget for the forthcoming year to meet some of the necessary costs. These
funds can be paid, as required, ageinst an Invoice from your Institute to the
Department of Genetics here. The amounts should be recorded as "for analytica!
services -- ultramicrospectrophotometry'’ or for ‘Instrumental components for
ultramicrospectrophotometry''. You should be able to recelve payments within
two or three weeks of the time we recelve the Involces.

Ellfott has helped to clerify some of the Issues raised In your letter, and
on the basis of his visit. | am particularly disturbed to learn of the residual
chromatism of the Zelss optics, and would be anxious to have a wore precise Indi-
cation of its extent from you. Since we wil! be using these optics for spectro-
graphy, the image for different wavelengths will be dispersed to different positions;
this suggests the possibility of compensating for the chromatism by distorting
the Image plene, or by Introducing figured prisms. is there any possibility of
obtaining actual measurements of the variation of focal parameters with weve-
length for the tenses?

In addition, as we heve already discussed, | would be most grateful for
some preliminary measurements with your present Instruments on some test samples,
@.g., the microblal concentrate that we recently sent to you. (It would be most
edventageous to have accompanying photomicrographs of the individual specimens
that you have selected for spectral measurements). We have been having some
difficulties In transferring our specimens fram Ludox to alcohol or to polyvinyl
sicoho! films, and there are some equally trivial (but vexatious!) technical
and personne! problems that have delayed this aspect of our work during the past
few weeks. However, you should soon rece!ve some additional specimens from us;
especially as we now have a small stock of .55 mm quartz cover glasses. These
will Include a few minerals that we might have reason to belleve might be sources
of artifacts or confusion, for example # ‘wonazite’ ore. | would also send you
some dust collections: It would be instructive to compare the observed spectra
of the obvious mineral particles and some of the larger spores, pollen grains,
etc., also to be found In these specimens. As you point out, It may be herolc
to leap Immediately to the measurement of j-micron objects, and we might relax
this condition for our first efforts, and at least unt!! we have somewhat better

COPY
Or. T. Caspersson 2 June 28, 1961

eppreciation of the kind of background signals that we might get.

| also appreciate your thoughtful comments on the oscil latory-focussing system.
There can be little doubt that some comparable mechanism, together with the fine
linear scanning, will be necessary. However, | belleve that it may save sone
duplication of effort If this study can be coofdinated with a general one on
automated microscopy. The NASA has recently sent out ‘requests for proposals''
to a number of Industrial contractors. Within the next two weeks, it will ba
evaluating these proposals, and one or two contractors will be selected to Make
a comprehensive engineering study. ! would like to suggest that one of these
concerns be apprised of your Interest and likely contributions to the design
conceptions, and that we then make same arrangement to coordinate these Ideas.
This should not preclude further Independent work <= especially as these will be
design (not fabrication) contracts at the early stages, and it may be important
to Improve the performance of our UMSP for calibration studies during the next
yeer. { trust you will give me the discretion to bring up this Idea with the
engineering groups thet are given the contract(s).

Needless to sey, | am as anxious to avold notorious publicity In
this area as you are. However, i must make sane mention of our relationship
In progress reports to NASA, and it ts concelvable that some of this may
eventually leak out. However, | do not think much public attention can come
of It unless your Swedish press are unusually attentive. On the contrary, |
fear that your contributions may be remphasized In some announcements
thet may appear, but | am sure you w understand how this might came about.

With cordial regards,
Joshua Lederberg
Professor of Genetics

Enc: Sample of 'Monazite’ ore for UMSP and micrography of a few particles.