THE EARTH. 205 



Lakes of Mexico, and of Titicaca in Peru, though 

 of no great extent, are, nevertheless, salt ; and 

 both for the same reason. 



Those who are willing to turn all things to the 

 best, have not failed to consider this saltness of 

 the sea as a peculiar blessing from Providence, in 

 order to keep so great an element sweet and 

 wholesome. What foundation there may be in 

 the remark, I will not pretend to determine ; but 

 we shall shortly find a much better cause for its 

 being kept sweet, namely, its motion. 



On the other hand, there have been many who 

 have considered the subject in a different light, 

 and have tried every endeavour to make salt water 

 fresh, so as to supply the wants of mariners in 

 long voyages, or when exhausted of their ordinary 

 stores. At first it was supposed simple distilla- 

 tion would do ; but it was soon found that the 

 bitter part of the water still kept mixed. It was 

 then tried by uniting salt of tartar with sea water, 

 and distilling both; but here the expense was 

 greater than the advantage. Calcined bones 

 were next thought of; but a hogshead of calcined 

 bones, carried to sea, would take up as much 

 room as a hogshead of water, and was more hard 

 to be obtained. In this state, therefore, have the 

 attempts to sweeten sea water rested ; the chemist 

 satisfied with the reality of his invention, and the 

 mariner convinced of its being useless. I can- 

 not, therefore, avoid mentioning a kind of suc- 

 cedaneum which has been lately conceived to an- 

 swer the purposes of fresh water, when mariners 

 are quite exhausted. It is well known, that per- 



