NATURAL PHILOSOPHY. 161 



THE BUOTANCr OF THE WATER OF THE DEAD SEA. 



" ABOUT sunset, we tried whether a horse and a donkey could swim 

 in the sea without turning over. The result was, that although the 

 animals turned a little on one side, they did not lose their balance. 

 A muscular man floated nearly breast-high without the least exertion. 

 A horse taken into the bay could with difficulty keep himself upright. 

 Two fresh hen's eggs floated up one third of their length ; they 

 would have sunk in the water of the Mediterranean or the Atlantic. 

 The water of the sea was very buoyant ; with great difficulty I kept 

 my feet down ; and when I laid upon my back, and, drawing up my 

 knees, placed my hands upon them, I rolled immediately over." 



"Tried the relative density of the water of this sea and of the At- 

 lantic, the latter from 25 north latitude, and 52 west longitude ; 

 distilled water being as 1. The water of the Atlantic was 1.02, and 

 of this sea 1.13. The last dissolved one eleventh, the water of the 

 Atlantic one sixth, and the distilled water five seventeenths of its 

 weight of salt. The salt used was a little damp. On leaving the 

 Jordan we carefully noted the draught of the boats. With the same 

 loads, they drew one inch less water when afloat on this sea than in 

 the river. Since our return, some of the water of the Dead Sea has 

 been subjected to a powerful microscope, and no animalcules or ves- 

 tige of animal matter could be detected." Lieut. Lynch's Expedition 

 to the Dead Sea and the Jordan. 



TO SEPARATE POTATOES OF DIFFERENT QUALITIES. 



WE learn from the London Patent Journal that Mr. James Ander- 

 son, of Glasgow, has secured a patent for a plan for the seemingly in- 

 significant purpose of separating potatoes of different qualities, but 

 the method adopted merits attention. According to experiment it 

 was found that a potatoe containing 20 per cent, of solid nutriment was 

 about the specific gravity of 1.080, that is, taking distilled water at 

 52 as unity, while the same root with 30 per cent, of nutriment is 

 of a specific gravity of 1.120. Taking this rule, which the patentee 

 found to be invariably correct, he is enabled to divide the vegetables 

 into two or more distinct classes. For this purpose he places them in 

 a vessel containing water brought to a density suited to the quality of 

 the article, which is easily effected by adding salt or clay to the water, 

 and then those which are of less specific gravity will float, while the 

 heavier ones will sink. These two qualities may be again immersed 

 in liquids of different specific gravity, and so again subdivided. 



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