December 23, 1948
Dear Mr. Holt:
Your letter of December 20 and the shipment of dried brewers yeast arrived this morning.  As many times before, we are amazed and gratified by the extreme cooperativeness and efficiency of your organization.  I might mention that only two weeks ago we processed in our own laboratory some ale yeast obtained locally.  The job of washing and drying this yeast consumed the facilities of our single cold room and over a week's time at a cost which far exceeded $100 and with a yield of only five pounds of yeast.  I mention this to emphasize our gratitude in having this large and excellent quantity of yeast which you prepared for us.  I am terribly sorry that under Government regulations it would be impossible to cover the additional costs that you sustained in preparing this yeast, and I hope that on future occasions you will make an estimate large enough to cover this deficiency.
With many thanks again for the great assistance that you have been to us.
Very truly yours,
Arthur Kornberg.