10 December 1685 – 16 December 1685

To Greenwich, being put into the new Commission of Sewers.

Dr. Patrick, Dean of Peterborough, preached at Whitehall, before the Princess of Denmark, who, since his Majesty came to the Crown, always sat in the King's closet, and had the same bowings and ceremonies applied to the place where she was, as his Majesty had when there in person. Dining at Mr. Pepys's, Dr. Slayer showed us an experiment of a wonderful nature, pouring first a very cold liquor into a glass, and superfusing on it another, to appearance cold and clear liquor also; it first produced a white cloud, then boiling, divers coruscations and actual flames of fire mingled with the liquor, which being a little shaken together, fixed divers suns and stars of real fire, perfectly globular, on the sides of the glass, and which there stuck like so many constellations, burning most vehemently, and resembling stars and heavenly bodies, and that for a long space. It seemed to exhibit a theory of the eduction of light out of the chaos, and the fixing or gathering of the universal light into luminous bodies. This matter, or phosphorus, was made out of human blood and urine, elucidating the vital flame, or heat in animal bodies. A very noble experiment!

I accompanied my Lord-Lieutenant as far as St. Alban's, there going out of town with him near 200 coaches of all the great officers and nobility. The next morning taking leave, I returned to London.