Chap. 106.] WONDEES OF FOUNTAINS AND EIYEES. 137 



these other wonderful operations of nature ; that copper and 

 lead sink when in a mass, but float when spread out^ ; and 

 of things that are equally heavy, some will sink to the bot- 

 tom, while others will remain on the surface" ; that heavy 

 bodies are more easily moved in water^ ; that a stone from 

 Scyros, although very large, will float, while the same, when 

 broken into small pieces, sinks'* ; that the body of an animal, 

 newly deprived of life, sinks, but that, when it is swelled 

 out, it floats^ ; that empty vessels are drawn out of the water 

 Tvith no more ease than those that are fulP ; that rain-water 

 is more useful for salt-pits than other kinds of water'' ; 

 that salt cannot be made, unless it is mixed with fresh water^ ; 

 that salt water freezes with more difficulty^, and is more readily 

 heated ^*^ ; that the sea is warmer in winter ^^ and more salt in 



1 Thin leaves or fihns of metal have little affinity for water, and have, 

 generally, bubbles of air attached to them ; so that, when placed upon 

 the water, the fluid is prevented from adhering to them, and thus they 

 remain on the surface. 



2 Depending not upon their absolute, but their specific gravity. 



3 Being partly supported by the water. 



"* The stone may have floated in consequence of its bemg fiill of pores : 

 these are more quickly filled with water when it is broken into small 

 pieces. It was probably of the nature of pumice or some other volcanic 

 product. 



5 This is well knoTVTi to depend u])on the commencement of the de- 

 composition of some part of the viscera, by wliich there is an evolution 

 of gaseous matter. 



^ Tliis is an erroneous statement ; it is not easy to ascertain what was 

 the som*ce of the error. 



' Rain, as it falls from the clouds, is nearly pure ; and rivers, or recep- 

 tacles of any kind, that are supphed by it, are considerably more free from 

 saline impregnations than the generality of springs. 



8 This statement is altogether incorrect. 



9 When salt water fi-eezes, it is disengaged from the saline matter wliich 

 it previously held in solution ; a greater degree of cold is therefore re- 

 quired to overcome the attraction of the water for the salt, and to fonn 

 the ice, than when pvu'C water is congealed. 



10 " Celerius accendi." We can scarcely suppose that by this term our 

 author intended to express the actual burning or mflammg of the water, 

 wliich is its literal and ordinary meaning. This, however, woidd appear 

 to be the o]:)inion of Hardoiun and Alexandre ; Lemafre, i. 419. Holland 

 translates it, "made hot and set a-seething," i. 46 ; Poinsuiet, " s'echaufto 

 le plus vite," i. 313 ; and Ajasson, " plus prompte h s'ecliauffer," ii. 217. 



11 The temperature of the ocean, in Consequence of its great mass and 

 the easy diil'usion and mixtiu'e of its various parts, may be conceived to 



