40 



Thus, compared directly with the chips, the inversion in the battery 

 was great. 



Judged by the same standards, there was at no other time during the 

 season so great an inversion of sucrose in the battery as during this 

 period of few cells and low temperatures. Nevertheless the character 

 of the cane was so good that the yield of sugar was large. Had, how- 

 ever, the cane been worked without the inversion spoken of, the yield 

 of sugar would have been twice as large. During the same period the 

 percentage of total sugars left in the exhausted chips was .80, while 

 before this time it had only been .17. 



It is therefore seen from the data given that the attempt to work the 

 battery with few cells and at a low temperature increased the sugar 

 left in the chips more than one- half, and caused a greater inversion of 

 the sucrose than was experienced at any other time during the entire 

 season. 



I call especial attention to these facts, because during the period 

 mentioned I was absent from Fort Scott. On my return I ordered the 

 battery to be worked with nine or ten cells under pressure and at a 

 uniform temperature of 70 C. This I believe to be the best method of 

 operating a diffusion battery for sorghum, at least until some method is 

 invented of distributing over the chips some substance which will neu- 

 tralize the acids of the cane and thus entirely prevent inversion. The 

 methods by which I attempted to accomplish this desirable result have 

 already been described. 



A further fact, which is illustrated by the analyses of the diffusion 

 juices from uninjured canes, is that the diminished purity is produced 

 solely by the extraction of gum and chlorophyll chiefly from the blades 

 and sheaths, and that this injury can be avoided by a proper cleaning 

 of the canes. 



With clean canes and those in which the sucrose is still uninjured no 

 alkaline substance will have to be used in the battery. When, how- 

 ever, deteriorated canes are used some such application will be necessary 

 to save the sucrose from further inversion. As has already been pointed 

 out, finely powdered lime or calcium carbonate evenly distributed over 

 the chips offer the simplest solution of the difficulty. 



MODIFICATION OF THE PROCESS OF CARBONATATION. 



In order to avoid the discoloration of the sirup, which is the chief ob- 

 jection to carbonatation, the following modification of the process was 

 adopted : 



The juice used was obtained from sugar-cane sent from Fort Scott to 

 Washington, and the experiments were made after my return from Kan- 

 sas. 



To the cane-juice was added 1 per cent, of its weight of freshly burned 

 lime, and the carbonatation was continued until the juice was almost 

 neutral. After raising to the boiling point to decompose sucro-carbon- 



