VOYAGE TO ALGERIA 181 



homeward direction. Here there is a sudden change from 

 yellow-green to a bright emerald-green, and accompany- 

 ing the change a sudden fall in the quantity of suspended 

 matter. Between Cape St. Mary and Cape St. Vincent 

 the water changes to the deepest indigo, a further dimi- 

 nution of the suspended matter being the concomitant 

 phenomenon. 



We now reach the remarkable group of rocks called 

 the Burlings, and find the water between the shore and 

 the rocks a strong green; the home examination shows 

 it to be thick with fine matter. Fifteen or twenty miles 

 beyond the Burlings we come again into indigo water, 

 from which the suspended matter has in great part dis- 

 appeared. Off Cape Finisterre, about the place where the 

 "Captain" went down, the water becomes green, and the 

 home examination pronounces it to be thicker. Then we 

 enter the Bay of Biscay, where the indigo resumes its 

 power, and where the home examination shows the greatly 

 augmented purity of the water. A second specimen of 

 water, taken from the Bay of Biscay, held in suspension 

 fine particles of a peculiar kind; the size of them was 

 such as to render the water richly iridescent. It showed 

 itself green, blue, or salmon-colored, according to the di- 

 rection of the line of vision. Finally, we come to our last 

 two bottles, the one taken opposite St. Catherine's light- 

 house, in the Isle of Wight, the other at Spithead. The 

 sea at both these, places was green, and both specimens, 

 as might be expected, were pronounced by the home 

 examination to be thick with suspended matter. 



Two distinct series of observations are here referred 

 to the one consisting of direct observations of the color 

 of the sea, conducted during the voyage from Gibraltar to 



