No, Mr. Williams, certainly not; if Mr. Drake [a solicitor of the English Railway Company] has purchased a 'Turner', he ought to know it is a Turner; I was once silly enough to look at a picture that I was told had been painted by me, and I found myself soon after stuck up in a witness-box, giving evidence about it; I then said I'll never be so silly again.
Notes from Wikiquote
Mr. Drake, the solicitor of the Railway Company, whom Mr. Turner saw when he executed the conveyance, requested Mr. Williams to ask Turner's permission to show him a picture he had purchased as a 'Turner'