30th April, 1958.
Dear Mr. Bawden,
As you probably know Rosalind Franklin died on the 16th April. She bore her illness with great courage and worked as best she could to the end.
Before Rosalind went into hospital for the last time at the beginning of April she and her student, K.C. Holmes, did make an attempt to get good specimens from the potato virus X you sent her.  They had no success however, and according to Rosalind (and as described to me by Holmes) the trouble seems to have been similar to that mentioned in her letter to you of 20th March.  The day after the virus arrived Rosalind tried to prepare 2 or 3 specimens from about 12 cc of the virus solution, using M/20 borate buffer at pH 7.5 as recommended by you.  The pellet was rather rigid, and could not be redispersed in the supernatant.  A little was taken up into solution, but the specimen formed showed rather low birefringence and gave a very poor X-ray photograph.
Holmes later tried with the remaining virus solution which had in the meantime been stored in the cold and was found to have a set of a gel.  It remained gel-like and even on addition of borate buffer -- and Holmes tried various buffer concentrations -- did not disperse, but broke up into small chunks.  The little that did dissolve gave a solution too dilute to be of any use.  There does not seem anything else obvious to try, unless you can suggest some procedure.  Do you want the virus back?  If you think it is still any good we could spin what is left (c. 30 mg) down and send it back to you.
I would also be grateful if you could help with two points arising out of the paper on the various TMV strains which you were kind enough to comment on recently.  One of the referees for "Virology" and the Editor want something stated about the "methods" of purification and the past histories of the particular virus preparations used in these investigations. Is there any other reference other than your paper in "Nature", or failing that, I would appreciate a sentence or two on this point that could appear after the mention of your name on page 5 of the enclosed manuscript.  Secondly, is it correct to say that the RNA content of both the bean and tobacco forms is the same as in the type strain?  This information is required in connection with the statement in the paper in the third last line on page 6.
Yours sincerely,
A. Klug.