Sugar Beet Investigations. 195 



directed in Wiley Agr. Anal. III., p. 10 1, were added; after shaking 

 the mixture it was made up to 100 c. c. with distilled water and again 

 thoroughly shaken. Then the entire contents of the flask were poured 

 on a ribbed filter, the first part cf filtrate being poured a second time 

 through the same filter ; the filtrate was thoroughly mixed and the 

 sugar in it determined by means of a " double compensating shadow 

 polariscope " now in general use for this purpose, using a 200 mm. 

 tube. This reading divided by two gives the per cent, of sugar in the 

 juice. 



Explanation oj Tables 



In the following tables we have given in the first three columns : ist, 

 degree Brix or per cent, of total solids in the juice ; 2d, per cent, of 

 sugar in the juice; and 3d, per cent, of purity of the juice. We will 

 consider : 



First : The Degree Brix or per cent, total solids in the juice. — Beet j nice 

 consists of water and solid matter consisting of sugar, mineral salts, 

 coloring matter, nitrogenous compounds, etc. The first beet juice in 

 the tables reads "19.9° Brix." This means that 19.9 percent, of that 

 juice is solid matter and the remaining 80.1 percent, is water; or, in 

 other words, in 100 pounds of such a juice there are 19.9 pounds solid 

 matter and 80.1 pounds of water. 



Second : The per cent, of sugar in the juice. — This per cent, is deter- 

 mined by the polariscope. The first beet juice in the tables analyzed 

 17.25 per cent, of sugar. This means that in 100 pounds of that juice 

 there are 17.25 pounds of sugar. 



Third : Purity per cent. — This term is often called the coefficient of 

 purity, or, better still, the quotient of purity. It expresses the ratio 

 between \\\^ per cent, of total solids in the juice and \\\^ per cent, of sugar 

 in that same juice. That is, in any particular juice XhQ purity expresses 

 what proportion of the total solids is sugar. Thus, in the juice first 

 analyzed, in the following tables there is given, *^Fufitypercefit., 86.6." 

 This means that if such a juice were evaporated to dryness and the total 

 solid matter ol)tained, then of the solids thus obtained 86.6 per cent, 

 would be sugar and the remaining 13.4 per cent, would be impurities 

 not sugar; or stated in another way, in every 100 lbs. of the solid mat- 

 ter obtained by evaporating the juice, 86.6 lbs. would be sugar and the 

 remaining 13.4 lbs. would be impurities and not sugar. 



