104 NATURAL HISTORY. 



ness are indeed but privatives ; and therefore have 

 little or no activity. Somewhat they do contristate, 

 but very little. 



Experiment solitary touching the colour of the sea or 

 other water. 



874. Water of the sea, or otherwise, looketh blacker 

 when it is moved, and whiter when it resteth. 1 The 

 cause is, for that by means of the motion, the beams 

 of light pass not straight, and therefore must be dark 

 ened : whereas, when it- resteth, the beams do pass 

 straight. Besides, splendour hath a degree of white 

 ness ; especially if there be a little repercussion : for 

 a looking-glass with the steel behind, looketh whiter 



o o * 



than glass simple. This experiment deserveth to be 

 driven further, in trying by what means motion may 

 hinder sight. 



Experiment solitary touching shell-fish. 



875. Shell-fish- have been by some of the ancients 

 compared and sorted with the insecta ; 2 but I see no 

 reason why they should ; for they have male and fe 

 male as other fish have : neither are they bred of pu 

 trefaction ; especially such as do move. Nevertheless 

 it is certain that oystei s and cockles and mussles, which 

 move not, have no discriminate sex. Qucere, in what 

 time, and how they are bred ? It seemeth that shells 

 of oysters are bred where none were before ; and it is 

 tried, that the great horse-mussle with the fine shell, 



1 Arist. Prob. xxiii. 23. 



2 I believe Aristotle is alluded to. He divides the Exsanguia into four 

 classes, of which shell-fisli form one, and insects another. See Arist. De 

 Part. Animal, iv. 5. 1. ; and compare Cardan, De Rer. Variet. 



