82 CULTURE OF THE SUGAR BEET. 



may aid in determining it. We have seen above that the deposition of 

 sugar in the roots is almost always accompanied by a proportional depo- 

 sition of albuminoids and salts, and also that the relation found to exist 

 in the root is continued in the juice after extraction. These conditions 

 have an influence upon the separation of the sugar which the experience 

 of the manufacturer has taught him is unfavorable, and they will be 

 called up again in the treatment of the subject of manufacturing pro- 

 cesses, but in the present section we desire to call attention more par- 

 ticularly to the quantity of juice that may be extracted, the conditions 

 which may modify it, and the density of the juice as influenced by the 

 proportion of sugar present. 



Concerning the quantity of juice that may be extracted from roots, 

 much will, of course, depend upon the method employed for the purpose, 

 •though it is also modified by the character of the roots to be treated. 

 It is a well-known fact that rich beets will yield less of juice than poorer 

 '<anes, a quality governed to some extent probably by the more dense 

 character of the sacchariferous tissue, which is consequently more re- 

 sistant to the rasps in the former than in the latter kinds of product. 



Diibrunfaut, by observations upon beets grown by Decrombecque, 

 arrived at the following figures for the quantities of pulp left from treat- 

 ment. of roots of different degrees of richness: 



Advoeate&of various systems of presses claim better results, but these 

 ;figures may be accepted as a fair average of the work done on a large 

 scale, with the ordinary methods of rasping and pressing now in use. 



For the determination of the value of the juice after its extraction 

 various methods, are enqfloyed, and it would seem of value to call atten- 

 tion to them just here, since they must be used in the work the descrip- 

 tion of which must follow this. The methods which have found practical 

 application and are most convenient for industrial purposes for esti- 

 mating the sugar in juices are respectively based upon the density of 

 the juice, the influence of solutions of sugar upon the variation of the 

 plane of polarization of a ray of light passing through Nichols prisms, 

 and the amount of cupric oxide which may be reduced to cuprous oxide 

 by a given quantity of sugar. For the present purpose the estimation 

 of sugar alone, simply for the determination of the value of the juice and 

 consequently of the roots, will suffice for all requirements in the work 

 of selection of roots or any matters arising in the commercial relations 

 between the grower and manufacturer. 



Complete analyses are needed only in the manufacturing process 

 which must always be directed by a practical chemist for whom such 

 details would here be superfluous. Determinations by the first method 



