80 SUGAK BEET SEED. 



ured with a pipette and emptied into the test tiibe, 

 and then heated over a gas jet. This volume of the 

 blue liquor requires 0.05 grams of glucoSe before 

 becoming completely decolorized. Several cubic centi- 

 meters of the sugar solution are dropped into the test 

 liquor; repeated heating brings about changes in color, 

 passing from yellow to red, etc. 



After boiling for a few seconds, there will be 

 noticed a red deposit at the bottom of the test-tube. 

 This is the sub-oxide of copper which has been thrown 

 down; a few more cubic centimeters of the sugar solu- 

 tion are again added and the Hquid is boiled; the addi- 

 tion of the sugar solution and the boiling are repeated 

 from time to time, until the liquor becomes colorless. 

 If the sugar solution is used in excess, there remains a 

 yellow tinge, the intensity of which depends upon the 

 quantity above what was needed. Note is taken of 

 the number of cubic centimeters used to complete the 

 copper reduction. If this, for example, had been 

 7.3 c. c, it would correspond to 0.05 gram of glucose, 

 equivalent to the glucose obtained in the inversion of 

 0.0475 gram of sugar. In one cubic centimeter there 

 would be 0.05-^7.3, and in 100 c. c, in which have been 

 dissolved the sugar from five grams of beet, there is 

 0.05X100-^7.3, or 5-^7.3, which equals 0.685 gram 

 glucose, corresponding to 0.651 gram sugar. Conse- 

 quently, in 100 gratns of beet there is 20X0.651, equal 

 to 13.02 per cent, of sugar. 



Practical Application of the Violette Method. 



Some years ago, one of the leading beet-seed 

 growers introduced the Violette method into his lab- 

 oratory. A special machine worked by a pedal gave 

 the sample, the beet being placed beneath in a slanting 

 position; there were four cutting blades. The intro- 

 duction of the weighed samples into the flasks of 100 



