Copy of a letter, from Francis Jessop to Martin Lister Concerns whether 'crooked lines, which have been straightened, could be described geometrically, at least by points, and whether my laws were such as have been taken notice of by others...' ; believes that the white substance (mentioned in EL/I1/170) sent to the Royal Society was bitumen and that if Robert Boyle wished to carry out experiments with it or the 'fungus' (mentioned in EL/I1/170) then he could send some samples; discussing 'ignes fatuus' (fire flies); details about a man who rode into a bog and was surrounded by a blue flame Original letter was dated 3 February 1674 1674