29, 1659, it appears that Oldenburg and Jones were both much interested in the optical instruments of a certain Bressieux, then in Paris, who had for two years been chief workman in that line for Descartes.

They were anxious to make him a present of some good glass from London, because he was rather secretive about his workmanship, and such a present would go a great way towards mollifying him.[1] [Footnote 1: Letters of Oldenburg and Hartlib to Boyle in Boyle's Works (1744), V.280-296 and 300-302.] Very possibly with this last letter of Oldenburg's to Hartlib there had been enclosed a letter from Oldenburg, and another from young Ranelagh, to Milton.

Two such letters, at all events, Milton had received, and undoubtedly through Hartlib, who was still the universal foreign postman for his friends.

We can guess the substance of the two letters.

Young Ranelagh does not seem to have troubled Milton with his speculations on the generation of pearls, or his story of the German baron and his alchemic powders, but only to have sent his dutiful regards, with excuses for long neglect of correspondence.