168 



FBAGMENTS OF SCIENCE. 



Here we have three specimens of water, described as 

 green, a clearer green, and bright green, taken in 

 Gibraltar Harbour, at a point two miles from the 

 harbour, and off Cabreta Point. The home examina- 

 tion showed the first to be thick with suspended matter, 

 the second less thick, and the third still less thick. 

 Thus the green brightened as the suspended matter 

 diminished in amount. 



Previous to the fourth observation our excellent 

 navigating lieutenant, Mr. Brown, steered along the 

 coast, thus avoiding the adverse current which sets in, 

 through the Strait, from the Atlantic to the Mediter- 

 ranean. He was at length forced to cross the boundary 

 of the Atlantic current, which was defined with extra- 

 ordinary sharpness. On the one side of it the water 

 was a vivid green, on the other a deep blue. Standing 

 at the bow of the ship, a bottle could be filled with 

 blue water, while at the same moment a bottle cast 

 from the stern could be filled with green water. Two 

 bottles were secured, one on each side of this remarkable 

 boundary. In the distance the Atlantic had the hue 



