Experiments on the Production and Propagation of Light from the Phosphorus in Vacuo, Made before the Royal Society, by Mr. Fra. Hauksbee

most wholly consumed, having no Planks to guard it: But what I was most surprized at, was, that the Bones should be entire, tho probably interr'd 1500 years ago; for 'tis above so many Centuries since their Custom of Burning gave place to that more natural of Burying their Dead; which, according to Monsieur Muret, was re-introduced by the Antonines, who, being Philosophers and Virtuous Princes, could no longer endure that that kind of Cruelty should be exercised upon Humane Bodies. I have a Thigh-bone (which is wonderful light) and the lower Jaw, which was furnished with all the Teeth, but some of them are since stoln out; but tho the Bones are light, the double Coffins were so heavy, that they were forced to drag them out of their old Dormitory with a Team of Horses. VI. Experiments on the Production and Propagation of Light from the Phosphorus in Vacuo, made before the Royal Society, by Mr. Fra. Hauksbee. Experiment I. In pursuance to the Commands of this Honourable Society, Having a dark Room provided, the first Experiment was by drawing some Lines on a piece of blue Paper with the Phosphorus, which became immediately Luminous in the open Air, having a continual undulating Motion. This being plac'd under a Receiver, after some few Excursions, the Undulation ceas'd, but the Luminous Quality appeared to be in a great measure increas'd; the Receiver being farther exhausted, it became manifestly brighter; and so continued, till on the Admission of Air (which was gradually done) the Light sensibly diminishing all the while. But upon the Repetition of the Experiment, it was the Opinion of those Gentlemen then present, that it did not appear altogether so brisk or so vivid as at first. To Experiment II. To 2 or 3 small pieces of Phosphorus in a Glass Dish was added a small Portion of Oyl of Vitriol, Tartar per Deliquium, and Oyl of Cloves, which Mixture fir'd the Phosphorus in the open Air: But adding a little common Water, the Flame extinguish'd. This Preparation being included in a Receiver, very little light appear'd: But upon exhausting the Air, it became very apparent, and sent forth Vivid Steams. The Ingredients in the Dish (at the same time) appear'd very much to resemble a Boyling Flame, exhibiting a large Light; so that several Objects near it were render'd distinguishable, and continu'd so till the Air was admitted, at which time it became Opake. Nor would shaking the Engine (by which means the Mixture in the Dish was put in motion) produce any sensible Recovery of Light. Experiment III. A small quantity of the pre-mention'd Ingredients being put into a Bottle with a narrow neck, and included under a Receiver, appear'd then with very little Light; but on withdrawing the Air the Phosphorus began to be Luminous, and continu'd to increase, in proportion to the Rarification of the Air, issuing out of the Bottle in a Pyramidical form. At last (notwithstanding the Receiver was well exhausted) the Vivid Steams that were then emitted were so fine and subtile as to ascend in so thin a medium, reaching the upper parts of the Receiver (which was not tall) descending again by the sides thereof. Upon letting in the Air the Light perfectly vanish'd; and it would have been in vain (as I have often try'd) to have waited in expectation of its Recovery in the open Air. LONDON, Printed for Sam. Smith and Benj. Walford, Printers to the Royal Society, at the Princes Arms in St Paul's Church-yard, 1705.