November 7, 1923.
Dear Dr. Sabin:
I am encouraged to send you a reprint now twenty years old, which you will not find very complete, but which shows at least one way of stirring up the blood forming organs.  Undoubtedly other ways can be found.
This was a first publication on the subject and led to others which, however, do not exactly apply to what we have spoken about.
I do hope that you may really take my suggestion into account.  Something fundamental should be done about the anemias and leukemias, and you are the best person to do it.
I am really thrilled by the possibility.  I shall be in Baltimore before long and mean to talk with you further.
With many regards,
Yours sincerely,
Simon Flexner