CRICK, Francis (1916-2004). Autograph letter signed (“Francis”) to Leonard Hamilton, Cambridge, 22 October 1952.

One and a half pages, recto and verso, 258 x 201mm (light spot towards bottom). On Cavendish Laboratory stationery, Department of Physics, University of Cambridge.

An early letter, mentioning Jim Watson and his work on TMV (tobacco mosaic virus), an important tool for cracking the genetic code. Crick is writing to fellow University of Cambridge alum, Leonard Hamilton, who was then working at Sloan Kettering. In full: “Dear Leonard, I’m sorry not to have replied before, but I’ve been away sick with a persistent sore throat. As far as I know there is no E.M. work on T.M.V. here, and I haven’t heard of any anywhere else. Jim Watson, who has been taking x-ray photos of T.M.V. tells me that there isn’t any E.M. work. However if I can find Coslett I’ll ask him.

I’ve now definitely accepted the Brooklyn job and we shall probably arrive towards the end of next August. Our family planning has gone a bit astray, so we’re unlikely to have another infant by then. Could you let us know the sort of cost of having one in New York? We don’t want to postpone it indefinitely. With best wishes to you & Anne. Yours ever, Francis.”

TMV is a single-stranded RNA virus and indeed it was Watson’s x-ray photographs of it that allowed him to document its helical construction, an important step towards realizing the double-helix structure of DNA just months later. TMV was also the first virus visualized in the electron microscope (EM), in the late 1930s. Though electron microscopes have of course improved greatly in the past 80+ years, even today scientists still can't see genes directly with them.