Fifteenth and Sixteenth Centuries 87 



culosis. Cardan, professor of mathematics at Milan, a physician, 

 astrologer, and philosopher, was one of the most unusual men of 

 the Renaissance, and it is unfortunate he did not pay more atten- 

 tion to luminescence. There is little on this subject in his two most 

 important publications. De Suhtilitate Rerum (1551) and De 

 Rerum Varietate (1557) , which contain his philosophical writings. 



Luminous fish are also mentioned in an early work of Giambat- 

 tista della Porta (1538-1616), the Magia Naturalis libri IIII, pub- 

 lished at Naples in 1558 when he was only twenty years old. How- 

 ever the observation was not original with Porta, who was merely 

 eager to extol " the things which plentiful and lavish nature lends 

 so liberally to human usage, even the secret and hidden ones . . . 

 that impress our senses at night," ^^ and show their benefit to man- 

 kind. He listed the various luminescences known to the ancients, 

 such as glowworms, fungi, scales of fishes, pholads, the milvas (gur- 

 nard, a species of Trigla, " called lucerna ^^ because its eyes shine 

 at night ") , trunks of rotten oaks, etc., as well as " sea water, gleam- 

 ing with fiery sparks, which has been stirred by hands." Porta then 

 gave as an example of the use of such things his famous formula for 

 the preparation of a luminous liquid from the firefly and declared 

 that a similar liquid, " which we have often seen being separated," 

 could be made from the scales of fishes. 



In 1589 Magia Naturalis libri IIII was expanded to libri XX and 

 wholly changed, with less occult and superstitious matter. The 

 twenty books appeared in many later editions and languages, includ- 

 ing an English Natural Magick in Twenty Bookes (London, 1658) . 

 There is no mention of luminescences in this edition. 



The other famous reference to luminous flesh is contained in the 

 writings ®* of Girolamo Fabrizia (Hieronymus Fabricius ab Aqua- 

 pendente, 1565-1619) , pupil of Vesalius and teacher of William 

 Harvey (1578-1657) . An account taken from Fabricius is given by 

 Joseph Priestley in The History and Present State of Discoveries 

 Relating to Vision, Light and Colours (1772: 563). Priestley wrote: 



When three Roman youths, residing at Padua, had bought a lamb, 

 and had eaten part of it on Easterday 1592, several pieces of the re- 

 mainder, which they kept till the day following, shone like so many 

 candles, when they were casually viewed in the dark. Part of this 

 luminous flesh was immediately sent to Aquapendente, who was pro- 



** The quotations are from a translation by Mrs. A. Holborn. 



^^ The " lucerna piscis " of Pliny (see Chap. I) may have been the gurnard. R. 

 Dubois has called attention to the " pseudoluminescence " of this fish, a reflection of 

 light from the tapetum of the eye (Com. Rend. Ac. Sci., Paris, 178: 1030-1032, 1924) . 



"^De visione sive de oculto visus organo bound with De voce and De auditii, Chap. 

 4, pp. 43-45, Venetiis, 1600. 



