132 History of Luminescence 



published as the first part of Willis's Practice of Physick (London, 

 1681) . For Willis, fermentation, involving motion of particles, was 

 responsible for practically all phenomena, the dissolution of ma- 

 terials in solvents, as well as fire, heat, and light, even life itself. 

 Combustion was no more than fermentation. 



An explanation of luminescences by fermentation was undertaken 

 in the Zymologia Physica, or a Brief Philosophical Discourse of Fer- 

 mentation, from a New Hypothesis of Acidum and Sulphur (Lon- 

 don, 1675) , by a London physician, William Simpson. The book, a 

 pamphlet of 149 pages, was dedicated " To the Right Honorable 

 the President and Fellows of the Royal Society." It deals not only 

 with chemical matters of medical interest, but also discusses such 

 things as hot baths, generation of minerals, and development of 

 heat in haystacks and manure piles, as well as fire and light in 

 general. Its interest lies in Simpson's obscure explanations. 



Simpson listed a large number of luminous phenomena recognized 

 at the time in connection with his treatment of 



. . . Light as it is communicable to us from the great Fountain thereof, 

 the Sun, which, as we suppose, consists in an illumination of Air by a 

 perpetual emanation or eradiation of solar beams, springing from an 

 incessant, but peculiar Fermentation in the body of the Sun, and fos- 

 tered by an unwearied circulation of ^Ethereal matter, Light and 

 Heat. . . . 



Our design at present is, onely to discourse of the nature and manner 

 of such sort of Lights, which we find amongst bodies we usually con- 

 verse with upon the Earth, and within the verge of our Atmosphere: 

 which are as followeth, viz. the Light of culinary Fire, I mean, of most 

 usual combustable concretes, the Light of all Sulphurous matters, whether 

 in the form of mineral SulpJiurs, Gum7ns, Rosins, Turpeyiiine, Axungia's, 

 &c. or in liquids of Bitumen, Oyles, vinous Spirits, Sec. The Light of 

 rotten Wood, long dry'd Fish, as Codds, &c. who have an incipient putre- 

 faction; the Light of Glow-worms, Cats-eyes, Light from attrition of 

 Wood green or dry, which have thereby taken Fire, from the attrition or 

 percussion of Steel and Flint, or any Pyrites, from the frication or pecta- 

 tion of animals: such as are Light from the Combing a Womans head 

 (as sometimes hath been known) Light struck in the currying of a Horse; 

 and that Light I have seen from a sudden frication upon a Catts-Back; 

 of some Liquors, the Light of subterraneal Lamps; the perpetual Light 

 preparable by the exuberate Mercury of the Philosophers, graduated by 

 circulation and cohobation, according to our English Anonymus, who 

 had seen it done. 



The Light of some precious Stones, as Carbuncles; some sort of Dia- 

 monds, magnetical of Light, as the Bononian-stone, prepared by an arti- 

 ficial calcination. Lastly, The Light of meteors, amongst which may be 

 reckoned Lightening, flashes of Fire, or Light seen in Storms upon the 



