808 Fluctuations 



began to sink. Their specific weight at that mo- 

 ment was determined and considered to be a 

 measure of the corresponding value of the beet. 

 This principle was afterwards improved in two 

 ways. The first was a selection after the salt- 

 solution-method, but performed on a large scale. 

 After some few determinations, a solution was 

 made of such strength as to allow the greater 

 number of the beets to float, and only the best 

 to sink down. In large vessels thousands of 

 beets could be tested in this way, to select a 

 few of the very heaviest. The other improve- 

 ment was the determination of the specific 

 weight of the sap, pressed out from the tis- 

 sue. It was more tedious and more expensive, 

 but more direct, as the influence of the air- 

 cavities of the tissue was excluded. It pre- 

 pared the way for polarization. 



This was introduced about the year 1874 in 

 Germany, and soon became generally accepted. 

 It allowed the amount of sugar to be measured 

 directly, and with but slight trouble. Thou- 

 sands of beets could be tested yearly by this 

 method, and the best selected for the production 

 of seed. In some factories a standard percent- 

 age is determined by previous inquiries, and the 

 mass of the beets is tested only by it. In others 

 the methods of taking samples and clearing the 

 sap have been improved so far as to allow the 



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