49 



Average third sugar wagon per ton cane pounds.. 16. 05 



Average total sugar per ton cane , do 179.93 



Per cent, of yield, sugars . w .'JiNi 



SPECIAL ANALYTICAL WORK. 



Several problems were presented during the progress of the work at 

 Magnolia for solution. It is difficult to get time during the progress 

 of manufacture to study such special problems ; as much time, how- 

 ever, as I could take from the general supervision of the work was given 

 to this special analysis. 



COMPARISONS OF DIRECT AND INDIRECT POLARIZATION. 



If sorghum and cane juices were composed alone of a solution of su- 

 crose, the quantity of this substance could be determined at once by a 

 direct polarization ; unfortunately for the simplicity of chemical manip- 

 ulation, such is not the case. These j uices contain other substances which 

 are optically active. In sorghum juices especially we find large quanti- 

 ties of substances present other than sucrose, which have the power to 

 affect the polarized ray. 



In cane juices the substances which tend to produce right-handed ro- 

 tation are soluble starch, so-called, and its derivatives, dextrine and 

 dextrose. 



Of the substances tending to produce left-handed rotation at ordinary 

 temperatures may be mentioned invert sugar and certain nitrogenous 

 bodies. 



Were these left-handed and right-handed bodies present in neutral- 

 izing proportions they would have no effect upon the polariscopic de- 

 terminations of the sucrose, but such is not always the case ; hence, a 

 direct reading on the polariscope of sugar juices can not always be re- 

 lied upon to give exact data concerning the proportion of sucrose pres- 

 ent. 



In the case of juices the variation may not be marked, but after con- 

 centration a direct polariscopic reading of the masse cuite, or molasses, 

 may prove very erroneous. 



To determine the magnitude of this variation in the juices of sirups 

 and molasses from sugar cane, the following analyses were mado. 



In Table No. 50 are found data relating to clarified juices. 



These samples were taken with the greatest care. The measurements 

 were made in tared flasks, with a weighed quantity of the juice, and 

 all of the analytical operations conducted with the greatest precautions. 

 It will be seen by consulting the mean data of the table that the per- 

 centage of sucrose was increased from 14.49, the direct reading, to 14.67, 

 the percentage given by the polariscope after inversion. The mean 

 quantity of sucrose is increased by about one-third of the percentage of 

 the reducing sugar present. 

 23576 Bull 18 4 



