On the 9th of June, Messrs. Watson, Thistlewood, Preston, and Hooper, were conveyed from the Tower, where they had been confined, to the Court of King's Bench to be tried for high treason. Watson was tried first. His trial lasted _seven days_, at the end of which he was acquitted. The Attorney-General then gave up the prosecution against the others. The principal witness called by the Crown was the famous Mr. _John Castles_, the worthy gentleman who feigned asleep in my room at the Black Lion, Waterlane, on the evening after the first Spafields meeting, and the same worthy who met me in Cheapside, as I was driving to the second meeting on the second of December, and who kindly invited me to go to the Tower with him, which he assured me was in the possession of young Watson. What follows is curious and worthy of notice. It was publicly known that _Castles_ was to be the principal witness against his former associates. I therefore sent a gentleman, to inform the attorney for the prisoners, that I had become acquainted with certain circumstances, relating to this Mr. Castles, which would be of infinite service to his clients. This message was sent a fortnight before the time fixed upon for their trial; but the 9th of June approached without my having received any answer. I sent a second message, by another person; but, as no notice was taken of it, I sent a third person, on the 8th, to say that I was in town, and unless it was intended to hang the prisoners, I expected that I should be subpoened, and that I was come to town on purpose to give my evidence. In fact, this third message rather conveyed a demand than a request, and I was next morning subpoened.