4S ON LUMINOUS ANIMALI. 



Supposetl by ' Carradori adopts on this subject the doctrine of Brugna- 

 him and Brug. 4. ii' i -i. au i • i» • . 



natelli tube '"» ^"" ascribes the luminous appearances of animals to 



the matter of the condensation and extrication of light in particular or- 

 '^'"* ga»s, which had previously existed in combination whh the 



substance of their bodi(^s. He supposes the light to be 

 originally derived from the food, or the atmospheric air 

 taken into the body : in short, that certain anirtials have 

 tl:e peculiar property of gradually imbibing light from 

 foreign bodies, and of afterward secreting it in a sensible 

 form *. 

 Experiraents The following experiments, which t made upon this sub- 

 by the author, ject, would lead me to make diliereiit conclusions than those 



of the preceding authors. 

 Glow-worm in Exp, 1. A glow-worm was put into a glass oF water, in 

 water lunji- which it lived nearlv two hours, and continued to emit lio^ht 



UOUS. , -1 • j" J 1 11- 



as usual, until it died, when the luminous appearance en- 

 tirely ceased. 

 The substance Exp* 2. The luminous substance was extracted from the 

 not luminous beforementioned glow-worm, and from others killed in dif- 



' ferent ways; but it atforded no light, 

 but luminous Exp, 3. The sacs containing the luminous matter were 

 ■when taken cut from the bellies of living glow"Worin8, and shone unin- 

 animair"^ terruptedly 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 unremittingly for 

 48 hours. 

 Not luminous Exp. 4. The luminous substance of a glow-worm was 

 by heat. exposed to a degree of heat, which would have been suf- 



ficient to inflame phosphorus, without increasing the bril- 

 liancy of its light ; and farther, it could not be made to 

 burn by being applied to a red hot iron, or to the flume of a 

 candle. 

 A little heat Exp, 5. A delicate thermometer was introduced among 

 apparently some living glow-worms, during the time they gave out 

 evolved during i .• i i r i i • r« i 



the shinin*' of f""^'h light: the temperature ot the room being 09, the 



jlow-worras, instrument rose to 75, 76, and 77, according to circum- 

 stances, as the warmth was reflected from the hand, or dis" 



* Acnal di Chinuca, Tomo xiii. 1797. 



bipated 



