548 History of Luminescence 



that luminous wood became no brighter in oxygen than in air, a 

 correct observation, but he did not elaborate on the discovery. 



In 1789 the experiments on oxygen (reiner Luft) were repeated 

 by Beckerhinn, whose results did not agree. The wingless female 

 glowworm obtained near Strassburg luminesced no brighter in 

 oxygen than in " gemeiner Luft," a difference attributed to the use 

 of the female rather than the male glowworm. Beckerhinn also 

 tested other gases and found that the glowworms lived a long time 

 in non-respirable gases, except for " salpeter-, salz-und vitriolsauren 

 Luft " where they died in ten minutes. It is certain that Becker- 

 hinn's gases were not very pure. 



A much more careful research was carried out by Lazaro Spal- 

 lanzani (1796) . He had found the light of luminous wood and a 

 dead squid to become weak in nitrogen and return in the air, while 

 in oxygen the light was brighter. The light of the lucciole actually 

 disappeared in nitrogen, hydrogen and CO2, and Spallanzani was 

 impressed with the similarity in behavior of all these luminescences 

 and that of phosphorus in different gases. He took the similarity to 

 mean that they were all due to a slow burning. 



The next student of firefly chemistry was G. Carradori (1758- 

 1818), a professor at Pisa, whose paper on the luciole, Lampyris 

 italica, appeared in the Antiales de Chimie (1797), and was trans- 

 lated for the Philosophical Magazine (1798) , as well as in the 

 Annalen der Physik (1799) , Carradori ^^ criticized Spallanzani's idea 

 that the light was due to a slow burning, since he had found the 

 phosphoric matter to shine under oil " without a single air bubble," 

 and in a barometric vacuum. He thought that the bright light in 

 oxygen observed by Forster did not 



depend upon a combustion more animated by the inspiration of this 

 gas, but on the animals feeling themselves, while in that gas, in a better 

 condition . " Whence then arises," says the author, " the phosphoric light 

 of the luciole? I am of opinion," adds he, " that the light is peculiar 

 and innate in these insects, as several other productions are peculiar to 

 other animals. As some animals have the faculty of accumulating the 

 electric fluid, and of keeping it condensed in particular organs, to diffuse 

 it afterwards at pleasure, there may be other animals endowed with the 

 faculty of keeping in a condensed state the fluid which constitutes light. 

 It is possible that by a peculiar organization they may have the power 

 of extracting the light which enters into the composition of their food, 

 and of transmitting it to the reservoir destined for that purpose, which 

 they have in their abdomen. It is not even impossible that they may 

 have the power to extract from the atmospheric air the luminous fluid; 



" Quotations are from the Phil. Mag. 2: 77-80, 1798. 



