2^8 Mr. Delaval on the Cauje of the 



Sir Ifaac Newton, and others, have fuppofed 

 that the green colour of the fea is produced by 

 the refledive power of the water. But, aflual 

 obfervations do not confirm, or agree with this 

 opinion. 



When fea water is adnnitted into a refervoir, 

 which does not exceed a few inches in depth, the 

 water appears pellucid and colourlefs. Ft is 

 therefore manifeft, that no colour is reflcded from 

 its furface. Confequently, the water of the fea, 

 confidered as an uniform extended mafs, does not 

 reflecl any colour. 



Sea water abounds in heterogeneous particles. 

 Magnefia is procurable from its analyfis: calca- 

 reous earth may be obtained in the fame manner, 

 and manifefts itfelf in the numerous fliells, corals, 

 and other calcareous concretions, which arc 

 formed in it. The ftrata, which compofe the 

 bottom, and (hores, of the fea, alfo furnifh 

 various faline, metallic, bituminous, and other 

 matters. The animals, and vegetables, which it 

 nouriihes, contribute to the produdion of ex- 

 traneous particles. All thefe receive an addition 

 from the rivers, which conftantly difcharge their 

 contents into the fea. 



Many of the earthy, and other, particles ac- 

 cede, in denfity, fo near to water, that, when 

 they intercede that medium, their refledive 

 power mufi: be very weak: but, as they do not 

 entirely coincide with water, in denfity, they 



muft; 



