Observations upon Luminous Animals: 99 
it was also lost by cold, and revived by the-application of a 
warm temperature. He conjectured that the luminous 
matter of these insects was composed of hydrogen and car- 
bonated hydrogen gas. a 
Forster relates, in the Lichtenberg Magazine for 1783, 
that on putting a lampyris splendidula into oxygen gas, it 
gave as much light as four of the same species in common 
air. 
Carradori bas made some experiments upon the lucciole, 
(lampyris italica) which led him to deny its phosphores- 
cence. He found that the luminous portion of the belly 
of the insect shone in vacuum, in oil, in water, and different 
liquids? and under different circumstances, where it was 
excluded from all communication with oxygen-gas. ‘He 
accounts for the result of Forster’s experiment, by supposing 
that the worm shone more vividly, because it was more ani- 
mated in oxygen gas than in common air. 
Carradori adopts on this subject the doctrine of Brugna~ 
telli, and ascribes the Juminous ‘appearances of animals to 
the condensation and extrication of heht in particular or- 
gansyewhich had previously existed in combination with 
the substance of their bodies. Ele supposes the light to be 
originally derived from the food, or the atmospheric air 
taken into the body; in short, that certain animals have 
the peculiar property of gradually inbibing light from 
foreign bodies, and.of afterwards secreting it in a sensible 
«, form *. 
The following experiments which I made upon this sub- 
ject, would lead me to make different conclusions than 
those of the preceding authors. 
Experiment 1.— A glow-worm was put into a glass of 
water, in which it lived nearly two hours, and continued to 
emit light as usual, until it died, when the luminous ap- 
pearance entirely ceased. 
Lxpertment 2.—Vhe luminous substance was extracted 
from the beforementioned glow-worm, and from others 
killed in different ways, but it afforded no light. 
Experiment 3.—The sacs containing the Juminous matter 
were cut from the bellies of living glow-worms, and shone 
uninterruptedly for several hours in the atmosphere, and 
after their light became extinct, it was revived by being 
moistened with water; some of these were put into water 
in the first instance, in which they continued to shine un- 
Temittingly for 48 hours. 
# © Annal di Chimica, tomo xiii, 1797, 
G2 Experi- 
