312 History of Luminescence 



was printed in another book of Liceti, entitled De Lunae Subobscura 

 Luce Prope Conjunctiones etc. (Utini, 1642) . 



ATHANASIUS KIRCHER 



Knowledge of the Bolognian stone spread throughout Europe. 

 Athanasius Kircher of Fulda (1601-1680), who was in Rome in 

 1635, devoted four pages to it in his book on magnetism, Magnes, 

 sive de Arte Magnetica, published in Rome, 1641, and gave the same 

 account in his book on light, Ars Magna Lucis et Umbrae, Rome, 

 1646. His interest lay in the comparison of a phosphor which attracts 

 light to a magnet which attracts iron. 



Speaking of the variety of the stone which he found at Tolpha, 

 Kircher said: 



This fossil is a certain selenitic mass of sulphuric gypsum much mixed 

 with arsenic, antimony and copperas water [chalcantium], and easily re- 

 solved to a gypsum calx. The smell proves more than sufficiently the 

 presence of sulphur, the transparency indicates the presence of selenite, 

 the burning and depilatory power arsenic, the ability to cause vomiting, 

 antimony and finally the caustic action, copperas water.^^ 



Kircher described the methods of preparing the( phosphor from the 

 stone (called " lapis phengis ") and discoursed on the cause of the 

 light: 



Just as the marvels of this prodigious stone have excited admiration 

 among philosophers, so also has it by its miraculous light stimulated 

 many to enquire with all zeal as to the cause of this so rare effect. There- 

 fore, as usually happens with respect to things that are new and rare, 

 various opinions have been expounded by various men. Some indeed, 

 when they saw this stone shut up in a box and carried into a dark place 

 and at the same time preserve its light without any dependence on a 

 luminous body, thought that light was a substance, against the uni- 

 versal opinion of philosophers, and that the stone carried the light in 

 the same way that naphtha attracts fire and a magnet iron. Some thought 

 that the light was a property of some fiery and celestial substance and 

 that the stones shone in the darkness in the same way as all other 

 noctilucent bodies; others that the stone is kindled by the light sur- 

 rounding it depending on the atomic particles, into which they think 

 it is resolved. Others have proposed different theories. ^^ 



Kircher branded all these explanations as " frivolous, falacious and 

 with no foundation in truth." He denied that the " light is a celes- 

 tial quality inherent in the stone." Its light is quite different from 

 the light " in Noctiluca, a decaying oak, the cincindela, the eyes of 



^* Translated by R. A. Applegate. 



