IGO 



THE ULTIMATE SOURCE 



the sea, has been taking- place instead. Rains and rivers 

 have been washing- the hills and valleys of the earth of 

 their soluble salts, and large quantities of sodic chloride 

 have beeu carried back to the ocean. It has been calcu- 

 lated that the River Mahauady, which discharges into the 

 Bay of Bengal, near Cuttack, carries into it in solution, 

 daily, about 3,000 tons of sodic chloride. Much of this 

 salt is, doubtless, restored to the sea from the Silurian or 

 Cis-Indus salt deposit, the very oldest known. This process 

 has been going on for some thousands of years, so that the 

 sea is probably now stronger in salts than it was in the 

 Tertiary period, but the difference would be in any case 

 trifling. The effect of salt manufacture over the world may 

 be neglected, since bay salt obviously soon comes to form a 

 surface deposit, which regains the sea within a few years. 



From all this, it is evident that the palseothalassic sea 

 was hardly different, in specific gravity, or salinity, from 

 that which now exists, and that therefore the same species of 

 plants and animals could flourish in it. This conclusion 

 agrees with that arrived at by palaeontologists working 

 on a different line. They found the marine fossil fauna 

 and flora of the very earliest times so little different from the 

 primitive types now existing, that they conjectured them 

 to have lived under marine conditions similar to those now 

 obtaining. With regard to the salt restoration process, it 

 may be interesting to note that a cubic mile of rock salt 

 weighs 6,111,298,900 tons, taking the weight of a cubic foot 

 at 93 lbs. Ten large rivers, such as the Mahanady, carrying 

 off 3,000 tons a day, would require over six thousand years 

 to dispose of one cubic mile, so that there is no immediate 

 prospect of a rock salt famine. Mr. Warth's mine alone 

 would keep us in rock salt for 60,000 years. 



We have now traced the salt back into the palseothalassic 

 sea. Let us go back one step further and try to obtain a 



