76 phil6sophical transactions. [anno 1666. 



some distance took it for the light of the moon through a window upon a ves- 

 sel of milk ; and by brisker circulation it seemed to flame. 



The fish at that time shone both from the inside and outside, but chiefly 

 from the throat, and such places as seemed a little broken in the boiling. The 

 observer took a piece that shone most, and fitted it both to his great micros- 

 cope, and afterwards to the little one ; but he could discern no light by any of 

 the glasses ; nor from any drops of the shining water, when put into the 

 glasses. And May 10, in the brightest rays of the sun, he examined in 

 the great microscope a small broken piece of the fish, which shined most the 

 night before, but could find nothing on the surface of the fish very remarkable. 

 It seemed whitish, and in a manner dried, with deep inequalities ; and a steam 

 rather darkish than luminous seemed to arise like a very fine dust from the 

 fish ; with here and there very small and almost imperceptible sparkles in 

 the fish. 



The great microscope being fitted in the day-light for this piece of fish, we 

 examined it that night, and it yielded no light at all, either by the glass or 

 otherwise. Finding it dry, he thought that the moisture of spittle, and touch- 

 ing of it, might cause it to shine ; which it did, though but a very little, in a 

 few small sparks, which soon became extinguished. This was observed with 

 the naked eye. 



He caused two fish to be kept for further trial, two or three days longer, 

 in very hot weather, till they were fetid, expecting more brightness, but could 

 fiind none either in the water by stirring it, or in the fish taken out of the 

 water. 



Remarks on a Letter in the Journal des Scavans of May 24, 1666. 



iV** 13, p. 228. 



Whereas the French author is of opinion, that it is unknown how much 

 time a heavy body requires to sink in water, acccording to a certain depth ; 

 he may please to take notice, that that has been made out in England by fre- 

 quent experiments ; by which several depths, found by this method of sound- 

 ing without a line, were examined by trying them over again in the same place 

 with a line, after the common way. And as to that quaere of his, whether a 

 heavy body descends in the same proportion of swiftness in water, that it would 

 do in air ? the answer is, that it does not ; but that, after it is sunk one or 

 two fathoms into the water, it has there arrived to its greatest swiftness, and 

 keeps after that an equal degree of velocity ; the resistance of the water being 

 then found equal to the endeavour of the heavy body downwards. 



