THE EARTH. 



smell :' he was also assured, by one of his ac- 

 quaintance, who was becalmed for twelve or 

 fourteen days in the Indian sea, that the 

 water, for want of motion, began to stink; 

 and that had it continued much longer, the 

 stench would probably have poisoned him. 

 It is the motion, therefore, and not the salt- 

 ness of the sea, that preserves it in its present 

 state of salubrity; and this, very probably, 

 by dashing and breaking in pieces the rudi- 

 ments, if I may so call them, of the various 

 animals that would otherwise breed there, 

 and putrefy. 



There are some advantages, however, which 

 are derii ed from the saltness of the sea. Its 

 waters be t ng evaporated, furnish that salt 

 which is use ; *or domestic purposes; and, 

 although In some places it is made from 

 springs, and, ii otners, dug out of mines, yet 

 the greatest quantity is made only from the 

 sea. That which is called bay-salt, (from 

 its coming to us by the Bay of Biscay,) is a 

 stronger kind, made by evaporation in the 

 sun : that called common salt, is evaporated 

 in pans over the fire, and is of a much inferior 

 quality to the former. 



Another benefit arising from the quantity 

 of salt dissolved in the sea, is, that it thus 

 becomes heavier, and, consequently, more 

 buoyant. Mr. Boyle, who examined the dif- 

 ference between sea-water and fresh, found 

 that the former appeared to be about a forty- 

 fifth part heavier than the latter. Those, 

 also, who have had opportunities of bathing 

 in the sea, pretend to have experienced a 

 much greater ease in swimming there, than 

 in fresh-water. However, as we see they 

 have only a forty-fifth part more of their 

 weight s-ustained by it, I am apt to doubt 

 whether so minute a difference can be prac- 

 tically perceivable. Be this as it may, as 

 sea-water alters in its weight from fresh, so 

 it is found also to differ from itself in different 

 parts of the ocean. In general, it is per- 

 ceived to be heavier, and consequently salter, 

 the nearer we approach the Line. b 



But there is an advantage arising from the 

 saltness of the waters of the sea, much greater 

 than what has been yet mentioned ; which is, 



a Boyle, vol. iii. p. 222. 



Phil. Trans, vol. ii. p. 297- Macrobius. 



that their congelation is thus retarded. Some, 

 indeed, have gone so far as to say, that c sea- 

 water never freezes : but this is an assertion 

 contradicted by experience. However, it is 

 certain that it requires a much greater degree 

 of cold to freeze it than fresh-water ; so that, 

 while rivers and springs are seen converted 

 into one solid body of ice, the sea is always 

 fit for navigation, and no way affected by the 

 coldness of the severest winter. It is, there- 

 fore, one of the greatest blessings we derive 

 from this element, that when at land all the 

 stores of Nature arc locked up from us, we 

 find the sea ever open to our necessities, and 

 patient of the hand of industry. 



But it must not be supposed, because in 

 our temperate climate we never see the sea 

 frozen, that it is in the same manner open in 

 every part of it. A very little acquaintance 

 with the accounts of mariners, must have in- 

 formed us, that at the polar regions it is em- 

 barrassed with mountains, and moving sheets 

 of ice, that often render it impassable. These 

 tremendous floats are of different magnitudes; 

 sometimes rising more than a thousand fee- 

 above the surface of the water;' 1 sometimes 

 diffused into plains of above two hundred 

 leagues in length ; and, in many parts, sixty 

 or eighty broad. They are usually divided 

 by fissures ; one piece following another so 

 close, that a person may step from one to the 

 other. Sometimes mountains are seen rising 

 amidst these plains, and presenting the ap- 

 pearance of a variegated landscape, with hills 

 and valleys, houses, churches, and towers. 

 These are appearances in which all natu- 

 ralists are agreed ; but the great contest is 

 respecting their formation. Mr. Buffon as- 

 serts," that they are formed from fresh-water 

 alone ; which congealing at the mouths of 

 great rivers, accumulate those huge masses 

 that disturb navigation. However, this great 

 naturalist seems not to have been aware that 

 there are two sorts of ice floating in these 

 seas; the flat ice, and the mountain ice : the 

 one formed of sea-water only, the other of 

 fresh/ 



The flat, or driving ice, is entirely com- 

 posed of sea-water; which, upon dissolution, 



d Krantz's History of Greenland, vol. i. p. 31. 

 ' Buffon, vol. ii. p. 91. * Krantz. 



