The Seventeenth Century 137 



because what is coated with this liquid burns with a harmless flame, 

 the liquid is called by some ignis frigidus. If we knew by which method 

 this type of phosphorus is prepared, this would shed considerable light 

 on this our disputation, but in the meantime we must content ourselves 

 with mere names; thought what is told about it indicates that this last- 

 mentioned liquid consists mostly of swiftly moving salts. The scientists, 

 so resourceful and diligent, through whose study the physical science 

 makes such wonderful progress, certainly deserve highest praise. 



DOMENICO BOTTONI 



Another Italian who devoted considerable space to cold light was 

 Domenico Bottoni (1641-1731), a physician of Messina and later 

 of Naples, who wrote on various physical phenomena. His book, 

 Pyrologia Topographica, etc. (Naples, 1692) was divided into three 

 parts. The first, " De Igne in Genere," gave a philosophical account 

 of the views held by various men, ancient and modern, on fire. The 

 second section, " De Ignibus Coelestibus," was devoted to " fires " 

 which produce light without being hot (" de ignibus lucidis non 

 ardentibus ") . Bottone discussed the difference between Lucem, 

 Lumen, and Ignem with special reference to the firefly (Nitedula) . 

 The third section was entitled, " De Ignibus Terrestribus," taking 

 up subterranean fires, especially the eruptions of Mount Aetna and 

 Mount Vesuvius. 



In the second part (pages 61 to 118) practically every type of 

 luminescence was mentioned— marine scintillations, fish, rotten 

 wood, glowworm, firefly and " cuciyo," Grimm's earthworms of 

 Coromandel, dactyli, various inorganic phosphors, luminescence of 

 skin and hair, and the aurora borealis. Bottoni held that motion 

 was the basis of these luminescences. He wrote: ®^ 



A fiery nature is inherent in everything shining . . . for, although heat 

 is not perceived on account of the fineness and looseness of some bodies, 

 it will be sufficient for producing fiery effects and for causing motion in 

 the air, as we have learned from many observations. . . . When the 

 wings [of a firefly] were tied together abandoning their constant move- 

 ment, the light faded. Likewise we have noticed that when the eyelids 

 of cats are sewn together so that they cannot move their eyes, their paths 

 which are illuminated at night are obscured. In the same way, the glitter 

 of the sea, of fish and putrid wood dejDcnds on motion. 



Bottoni believed that motion 



is the reason why fire-flies shine in the summertime, for the air is moved 

 more continually in the neighborhood of the sun. It is also the reason 



'^ The translations have been made by Mrs. Annemarie Holborn. 



