ITS PROPERTIES AND DIVISIONS. 315 



It was, however, an opinion of Dr, Halley, that however uniform 

 the saltness of the ocean may be in different parts of it at a given 

 period of time, its general mass has been progressively becoming 

 more impregnated with saline materials, and hence actually salter 

 to the taste, ever since the formation of the world j and he endea- 

 vours to ground a proof of the age of the world upon this circum- 

 stance. His paper, which is short and ingenious, is as follows. 



" There have been many attempts made, and proposals offered, to 

 ascertain from the appearances of nature, what may have been the 

 antiquity of this globe of earth; on which, by the evidence of sa- 

 cred writ, mankind has dwelt about COQO years ; or according to 

 the Septuagint above 7000. Bjt as we are there told that the for- 

 mation of man was the last act of the Creator, it is no where re- 

 vealed in Scripture how long the earth had existed before this last 

 creation, nor how long those five days that preceded it may be to 

 be accounted j since we are elsewhere told, that in respect of the 

 Almighty a thousand years is as one day, being equally no part of 

 eternity ; nor can it well be conceived how those days should be to 

 be understood of natural days, since they are mentioned as mea- 

 sures of time before the creation of the sun, which was not till the 

 fourth day. And it is certain that Adam found the earth, at his 

 first production, fully replenished with all sorts of other animals. 

 This inquiry seeming to me well to deserve consideration, and wor- 

 thy the thoughts of the Royal Society, I shall take leave to propose 

 an expedient for determining the age of the world by a medium, us 

 I take it, wholly new, and which, in my opinion, seems to promise 

 success, though the event cannot be judged of till after a long pe- 

 riod of time ; submitting the same to their better judgment. What 

 suggested this notion was an observation I had made, that all the 

 lakes in the world, properly so called, are found to be salt, some 

 more some less than the ocean, which in the present case may also be 

 esteemed a lake ; since by that term I mean such standing waters as 

 perpetually receive rivers running into them, and have no exit or 

 evacuation. 



" The number of these lakes, ithe known parts of the world, is 

 exceedingly small, and indeed on inquiry I cannot be certain there 

 are in all any more than four or rive, viz- 1st. The Caspian Sea ; 

 2dly, The Mare Mortuum, or Lacus Asphaltites; 3dly, The lake 

 on which stands the city of Mexico; and 4thly, The lake of Titi- 

 raca in Peru, which by a channel of about fifty leagues commujii- 



