Controversiæ de vera circuli mensura ... inter ... C. S. Longomontanum et Jo. Pellium.[[186]] Amsterdam, 1647, 4to.
Longomontanus,[[187]] a Danish astronomer of merit, squared the circle in 1644: he found out that the diameter 43 gives the square root of 18252 for the circumference; which gives 3.14185... for the ratio. Pell answered him, and being a kind of circulating medium, managed to engage in the controversy names known and unknown, as Roberval, Hobbes, Carcavi, Lord Charles Cavendish, Pallieur, Mersenne, Tassius, Baron Wolzogen, Descartes, Cavalieri and Golius.[[188]] Among them, of course, Longomontanus was made
mincemeat: but he is said to have insisted on the discovery of his epitaph.[[189]]
THE CIRCULATING MEDIA OF MATHEMATICS.
The great circulating mediums, who wrote to everybody, heard from everybody, and sent extracts to everybody else, have been Father Mersenne, John Collins, and the late Professor Schumacher: all "late" no doubt, but only the last recent enough to be so styled. If M.C.S. should ever again stand for "Member of the Corresponding Society," it should raise an acrostic thought of the three. There is an allusion to Mersenne's occupation in Hobbes's reply to him. He wanted to give Hobbes, who was very ill at Paris, the Roman Eucharist: but Hobbes said, "I have settled all that long ago; when did you hear from Gassendi?" We are reminded of William's answer to Burnet. John Collins disseminated Newton, among others. Schumacher ought to have been called the postmaster-general of astronomy, as Collins was called the attorney-general of mathematics.[[190]]
THE SYMPATHETIC POWDER.
A late discourse ... by Sir Kenelme Digby.... Rendered into English by R. White. London, 1658, 12mo.
On this work see Notes and Queries, 2d series, vii. 231, 299, 445, viii. 190. It contains the celebrated sympathetic powder. I am still in much doubt as to the connection of Digby with this tract.[[191]] Without entering on the subject here, I observe that in Birch's History of the Royal Society,[[192]] to which both Digby and White belonged, Digby, though he brought many things before the Society, never mentioned the powder, which is connected only with the names of Evelyn[[193]] and Sir Gilbert Talbot.[[194]] The sympathetic powder was that which cured by anointing the weapon with its salve instead of the wound. I have long been convinced that it was efficacious. The directions were to keep the