82 



SUGAR BEET SEED. 



arms containing five tubes, each of which is at once 

 filled with ID c. c. of the copper solution. 



In the burettes are placed the invert-sugar solu- 

 tions from samples of beets, as previously mentioned; 

 and a certain quantity of the inverted liquor is allowed 

 to drop into the copper solution. The tubes are at 

 once placed over a series of small gas jets, which soon 

 bring the mixed copper and sugar solutions to a state' 

 of ebullition, resulting in the precipitation of a portion 

 of sub-oxide of copper. During this operation the 

 next series of five tubes is being prepared arid is also 

 subEtquently heated. When the 25 tubes have had 



PIG. 31. Pipette stand. 



their copper solutions completely decolorized, the heat- 

 ing and addition of inverted sugar solution must cease. 

 As the main object is to throw out all beets not up 

 to a given standard, certain tables are used. If in the 

 tables we find that 6.3 c. c. of juice (which has been 

 prepared by transforming the saccharose into glucose) 

 is needed to precipitate the copper of the Violette solu- 

 tion, this means that the beet under consideration con- 

 tains 15 per cent, sugar. Consequently, if this volume 

 is prepared in advance and the reaction is not com- 

 plete, the conclusion is that the sugar percentage is 

 less and more juice is needed, say 7.9 c. c, which corre- 



