REPORT OF THE CHEMIST. 315 



Since it is difficult to accurately collect and weigh the fine bagasse 

 whicli the spent chips afford, the mean of the second column will be 

 found to represent more accurately the real extraction. It is certain 

 that with a good three-roll mill each 100 pounds of the spent chips 

 can be reduced to 30 j)ounds, one-third of wliich is combustible mate- 

 rial. Even if no attempt is made to use the bagasse as a fuel, the pres- 

 sure is to be recommended on the score of economy. There appears 

 to be no difficulty whatever in passing the chips through a three-roll 

 mill, and their soft and pulj)y state renders the pressure exceedingly 

 easy. 



Further reference to this point will be made in that part of the re- 

 port devoted to sugar-cane. 



MODIFICATION OF THE PROCESS OF CARBONATATION, 



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

 objection 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 

 Kansas. 



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- 

 ates the juice was filtered, and then 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 was 

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

 and evaporated to 40° B. 



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

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

 that it Avas found unnecessary to use any adetate of lead or any other 

 defecating material to prepare this sirup for polarization. The quan- 

 tity of phosphate of soda required to x^recipitate the lime in 5 liters of 

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

 Therefore 10 grams of the sodium j)hosphate 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 reapj)ear 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 sug- 

 gested is the absolute failure of the experiments to demonstrate the 

 commercial practicability of manufacturing sorghum sugar. The 



