LAWRENCE COLLEGE
Spploton, 4sconsin

January 29, 1951

Prof. J. Lederberg:
Department of Genetics,
College of Agriculture,
University of Wisconsin,
Madison 6,Wis.

Dear Prof. Lederberg:

Sorry I am so late in answering your letter of
January 18th but we are in the midst of semester
exams.. I have plenty of pure l-rhamnose which I
ean sell for 8 cents a gram. My quantities of d and
l-arabinose I find are down to small amounts and
the purity is not what it ought to be. I would be
glad to send you ten grams each of d and l-arabinose
gratis because I know it will be used for experimental
purposes if you can use the purity I have. One crystall-
ization would make it good material but I just do not
have the time to do it myself. I have considerable
quantities of both beta-methyl d and 1 arabinoside,
These both melt at 169° and have a rotation of +242
and -242 so they are probably not what you want.
These products are quite pure.

I am going to be in Madison Feb. 9th to talk to
the Southern Wisconsin Edtcation Association convention
at the Union at 1:30. If you would not need these sugars
until then I could bring them with me and see that you
got them.

Very truly yours,

do Koken
e ¢
Professor of Chemistr