46 

 v, 



tamed, and in addition that which resulted from the inversion of the 

 cane sugar. It now only remains to nearly neutralize the acid in the 

 solution, cool it, and execute the test and calculations for grape sugar 

 as before. Subtracting the percentage of grape sugar originally found 

 from that shown by the last determination gives the percentage of 

 grape sugar resulting from the inversion of the cane sugar. The per- 

 centage of cane sugar is .95 of the grape sugar produced by inversion 

 of the cane sugar. The soluble solids "not sugar " contained in the 

 juice may be estimated by subtracting the sum of the percentages ol 

 the two sugars from the entire percentage of soluble solids as deter- 

 mined by the hydrometer. 



THE OPTICAL METHOD. 



The optical method of determining the percentage of cane sugar de- 

 pends upon the fact that a beam ofrpolarized light is rotated to the right 

 in passing through a solution of this sugar. While the apparatus for 

 executing this test is expensive and the explanation intricate, the 

 manipulation is simple and rapid and the results satisfactory ; so that 

 it is probable that all well-regulated sugar factories will be provided 

 with these instruments. 



For many of the purposes of the factory the determinations of the 

 percentage of cane sugar is all that is required. The analyst will prob- 

 ably be able to make forty or fifty of these determinations per day by 

 the optical method, if so many are required. 



THE FURTHER SCIENTIFIC WORK. 



The money, skill, and knowledge which have during the last few years 

 been expended upon the sorghum plant have made available a new in- 

 dustry. The possibilities of this new industry can be fully understood 

 only on more fully considering some of the facts which chemical science 

 has made known. 



The analyses made at the Parkinson Sugar Works during the season 

 of 1887 by Dr. C. A. Orampton and Mr. Norman J. Fake, chemists of 

 the U. S. Department of Agriculture, are of great value in this connec- 

 tion, and when supplemented by the further work now in progress in 

 the laboratories of the Department at Washington will become a basis 

 for future work. 



In tables of analyses the percentages given are usually computed on 

 the weight of the juice contained in the cane. Those who are familiar 

 with the habit of the plant will readily see that the cane may be con- 

 sidered in three parts, viz: (1) The tops, including the seed and 12 to 

 18 inches of the upper part of the stalk; (2) the leaves, including the 

 leaf sheaths; (3) the body of the cane after the tops and leaves have 

 been removed. This body of the ai}e contains nearly all of the juice, 

 and practically all of the sugar. 



