No. 12.— 1860-1.] PROCEEDINGS. 1861. 



xv 



The Edinburgh Review states that this theory of Sir E. Tennent's, of 

 the desalinization of sea water by filtration (as already said, a phenomenon 

 opposed to one of the first laws of Chemistry) explains the occurrence 

 of fresh water on coral islands, and confutes the theory of Darwin, 

 that this arises from rain ; as rain falling on a substance already fully 

 saturated with sea-water would not be absorbed, but would flow off. Not 

 a doubt of it. But coral islands are not only not saturated, but so 

 much of them as is above the sea-level, three or four feet, is highly porous 

 and perfectly dry, and presents all the conditions for absorbing the 

 whole of the rain that falls on them. They present to the rain this 

 much head of water to push out the sea and expel it piston-wise so far i 

 as the coral bed descends, — the sea itself forming the wall of the reservoir. 

 A well dug deep into the coral to draw off the rain-water, with which 

 it is always nearly saturated up to low-water mark, is sure to secure a 

 supply. An illustration of the two not mixing together, if the pores 

 of the soil, rock or coral, be fine enough, may be obtained by making 

 the experiment with capillary tubes. 



The red colour with which the sea is tinged round the shores of 

 Ceylon, during a part of the S.W. monsoon, is due to the Proto-coccus 

 nivalis, or the Himatta-coccus, which presents different colours at different 

 periods of the year— giving us the seas of milk as well as those of blood. 

 The coloured water at times is to be seen all along the coast north 

 to Kurrachee, and far out, and of a much more intense tint in the 

 Arabian Sea. The frequency of its appearance in the Red Sea has 

 conferred on it its name. 



Our author mentions terraces of marine shells embedded in agglutinated 

 sand as prevailing all around the island at a level considerably above 

 highwater mark. The same thing obtains all around the shores of the 

 Mauritius, the Eastern Archipelago, the shores of Hindustan, the 

 Arabian Sea and Red Sea, and, I believe, along the coasts of nearly all 

 the seas in the world. The Reviewer states truly, that "this is an 

 unquestionable evidence of an upheaval — the evidence of subsidence is 

 more difficult to obtain.'' He is mistaken. From Cape Comorin to 

 Kurrachee on the one side, and so all around the shores of the Bay of 

 Bengal on the other, multitudes of mangrove roots, their fibres unbroken, 

 and obviously existing where they grew, are found embedded in blue 

 marine clay, from ten to twenty feet below the raised beaches, the 

 surfaces of which, Avhen formed, must themselves have been below 

 half-tide, — as clear an evidence of a previous depression as the beaches 

 are of an upheaval. 



