, WITH THE SALT WATER OF THE SEA. 509 



ceased to be perceptible in the boat at anchor ; and I obtained 

 water from the bottom, the middle, and the surface of the 

 stream. The water taken from the surface of the stream, was 

 fresh, and tasted like ordinary river water. The water taken 

 from the middle, was not perceptibly different; but that which 

 was brought from the bottom was sensibly brackish. The wa- 

 ter from the surface did not contain any salt, as a thousand 

 grains of it, when evaporated with care on a sand-bath, left on- 

 ly a grain and a half of residue, apparently mud, which, when 

 applied to the tongue, communicated no impression of salt- 

 ness. The water from the middle of the stream yielded two 

 grains of residue, when the same quantity was evaporated, of 

 a whiter colour than the former, and having a perceptibly salt 

 taste. The water from the bottom, which was saltish even to 

 the taste, yielded four grains of saline matter. According to 

 these experiments, the layers of water were arranged accord- 

 ing to their densities, the heaviest water occupying the bottom 

 of the stream, and the lightest floating on the surface. 



At half-Jloody I repeated the experiments on the waters ob- 

 tained from the same situations as before. The water at the 

 surface had now become very sensibly salt to the taste, and 

 thus gave decided proofs of the progress of the tide. The 

 three bottles of water now obtained, yielded results, not 

 in unison with those already taken notice of. The arrange- 

 ment of the different strata of water, according to their den- 

 sities, as observed at ebb-tide, was in some degree rever- 

 sed; for here the water at the surface was Salter than that 

 which was obtained from the bottom, and the water from the 

 middle was Salter than either. A thousand grains of water 

 from the bottom, yielded by evaporation only ten grains of sa- 

 line matter, while the water from the surface yielded eleven 

 grains, and from the middle twelve grains, by the same pro- 

 cess. 



3 S 2 This 



