98 A HISTORY OF 



may be considered as inland seas, are, nevertheless, fresh-water lakes ; 

 and kept so by the river St. Lawrence, which passes through them. 

 But those lakes that have no communication with the sea, nor any 

 -ivers going out, although they be less than the former, are, however, 

 always salt. Thus, that which goes by the name of the Dead Sea, 

 though very small, when compared to those already mentioned, is so 

 exceedingly salt, that its waters seem scarcely capable of dissolving 

 any more. The 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 Provi- 

 dence, 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 distillation 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 chymist satisfied with the reality of his invention ; and the mari- 

 ner convinced of its being useless. I cannot, therefore, avoid men- 

 tioning a kind of succedaneum which has been lately conceived to an- 

 swer the purposes of fresh-water, when mariners are quite exhausted. 

 It is well known, that persons who go into a warm bath, come out 

 several ounces heavier than they went in ; their bodies having im- 

 bibed a correspondent quantity of water. This more particularly 

 happens, if they have been previously debarred from drinking, or go 

 in with a violent thirst ; which they quickly find quenched, and their 

 spirits restored. It was supposed, that in case of a total failure of 

 fresh-water at sea, a warm bath might be made of sea-water, for the 

 use of mariners ; and that their pores would thus imbibe the fluid, 

 without any of its salts, which would be seen to crystallize on the sur- 

 face of their bodies. In this manner, it is supposed, a sufficient quan- 

 tity of moisture may be procured to sustain life, till time or accident 

 furnish a more copious supply. 



But, however this be, the saltness of the sea can by no means be 

 considered as a principal cause in preserving its waters from putre- 

 faction. The ocean has its currents, like rivers, which circulate its 

 contents round the globe ; and these may be said to be the great 

 agents that keep it sweet and wholesome. Its saltness alone would 

 by no means answer this purpose : and some have even imagined, 

 that the various substances with which it is mixed, rather tend to pro- 

 mote putrescence than impede it. Sir Robert Hawkins, one of our 

 most enlightened navigator*, gives the following account of a calm, ID 



