41 



ates the juice was filtered, and thru enough phosphoric acid added to 

 precipitate the lime remaining in solution. 



Since a slight excess of the acid will redissolve the precipitate and 

 form acid phosphate, sodium phosphate was substituted for the phos- 

 phoric acid. 



Much of the red color of the carbonatated juice was discharged by 

 this process. After the precipitation was complete the juice w-is again 

 boiled and filtered. It was then bleached with sulphurous acid and 

 evaporated to 40 B. 



In every instance the sirup made iu this way was very light in color, 

 perfectly transparent, and of the finest flavor. So pure was it, indeed, 

 that it was found unnecessary to use any acetate of lead or any other 

 defecating material to prepare this sirup for polarization. The quantity 

 of phosphate of soda required to precipitate the lime in 5 liters of juice 

 (11 pounds) was 100 cubic centimeters of a 10 per cent, solution. There- 

 fore 10 grams of the sodium phosphate are sufficient for 5,000 grams of 

 juice. About 4 pounds of sodium phosphate or 3 pounds of phosphoric 

 acid would be sufficient for working a ton of cane. 



The whole cost of treating cane juices with phosphoric acid or sodium 

 phosphate will not be over 15 cents per ton of cane. The phosphoric 

 acid, however, is not lost. It will reappear in the press cakes, having 

 lost only half its value. Hence the actual cost of using this method of 

 removing the lime is not probably over half of the estimate given above. 



I made every effort to get phosphoric acid at Fort Scott, but could 

 not succeed in time. 



I believe the modification of the process here suggested will make a 

 noted improvement in the molasses over any other procedure now in use. 



GENERAL CONCLUSIONS. 



In a general review of the work, the most important point suggested 

 is the absolute failure of the experiments to demonstrate the commer- 

 cial practicability of manufacturing sorghum sugar. The causes of this 

 failure have been pointed out in the preceding pages, and it will only 

 be necessary here to recapitulate them. They were : 



(1) Defective machinery for cutting the canes and for elevating and 

 cleaning the chips and for removing the exhausted chips. 



(ii) The deterioration of the cane due to much of it becoming over- 

 ripe, but chiefly to the fact that much time would generally elapse after 

 the canes were cut before they reached the diffusion battery. The 

 heavy frost which came the 1st of October also injured the cane some- 

 what, but not until ten days or two weeks after it occurred. 



(')) The deteriorated cane caused a considerable inversion of the su- 

 crose in the battery, an inversion which was increased by the delay in 

 furnishing chips, thus causing the chips in the battery to remain ex- 

 posed under pressure fora much longer time than was necessary. The 

 mean time required for diffusing one cell was twenty-one minutes, three 

 times as long as it should have been. 



