48,6 Qn the Light from organi/ed Bodi(% 



The Tadpole: 



Exper. lo. It occurred to my mind, in the year 1797, to try what effeft a faline men- 

 ftruum would have upon the tadpole. Accordingly, I procured feme tadpoles on the loth 

 of June, and put fix of them into a folution of two drams of Glauber's fait in two ounces 

 of water. On the nth, in the evening, the menflruuni was dark; on the 12th, after 

 fliaking the phial, I was agreeably furprifed to find it impregnated with light ; on the 13th, 

 the light was fo abundant as to float on the top of the tnenftruum ; on the 14th, the fame 

 phsenomenon appeared; on the 15th and i6th, it was (till prefcnt ; on the 17th, the 

 lucidnefs began to diminifli ; on the i8th, it was faint ; and on the 19th it had vanilhed. 



Exper. 1 1. On the nth of June, fix other tadpoles were dropped into a folution of one 

 dram of common fait in three ounces of water. On the 12th and 13th, the menftruum 

 was dark; on the 14th, it had extrafted from the tadpoles a very beautiful bright light ; 

 on the 15th, the menftruum was exceedingly luminous; on the i6th and 17th, nearly the 

 fame : the light then gradually faded, fo that on the 2ift it was merely vifible ; and on 

 the 22d it difappeared. 



Exper. 12. On the 2ift of June, the above two experiments were repeated; when the 

 tadpoles remained in the menftruums till the 27th, but no light was emitted. What was 

 the caufe of this failure in thefe two lafl; experiments ? Was it the ten days' increafed 

 growth of the animal, which was taken from the fame pond, that made the difference ? 



Exper, 13. The above experiments were repeated, when the tadpole had juft put on the 

 ftate of a frog, but without producing any lucid appearance. 



The Light it incorporated ivitk the whole Subjlance of Marine Fijhes. 



Exper. 14. A fine frefli herring, being gutted, was divided longitudinally into two 

 parts, both of which were hung up, by pieces of ftrlng, in the laboratory. On the ad 

 night, they were very lucid on the fkinny fide, but not on the flefhy or inward part; on 

 the 3d, the flefliy or central parts of the fi(h, were thickly covered with a rich azure 

 light ; on the 4th, they continued exceedingly luminous ; and on the 5th and 6th they 

 were ftill lucid. It is furprifing to think what a profufion of light Was emitted from the 

 interior fubftance of this fingle fi(h. 



Exper. 15. A fimilar experiment was made with a mackerel, and with fimilar effeSs, 

 Thefe two experiments were frequently repeated. 



Exper. 16. But the foft roe, of both the herring and the mackerel, abounds more with 

 light than even the flcfh. When it is in its moft luminous ftate, which generally happens 

 about the 3d or 4th night, it will fometimes ftiine fo very fplendidly, as to appear like a 

 complete body of light. It is remarkable that thp hard-roe, in general, does not emit fo 

 much light as the foft-roe. When the roes were ufedj they were laid upon plates, and de- 

 poCted-in the laboratory. 



A OBSER- 



