Letter, from Henry Oldenburg to Renatus Slusius, dated at London Wishes to know who should be entrusted with the original diploma of election to guarantee delivery of it to Slusius; that Boyle had published his 'Tracts about hidden qualities of the air'; that Wallis had published a dissertation on the gravity of fluids; that Malpighi's treatise had arrived which was illustrated with 54 phytological plates and instructed the Society to publish it; details a mathematical problem sent by Davenant 17 May 1675