DEOREE OF EXTRACTION BY EXPERIMENTAL MILL. 



DIFFICULTIES ENCOUNTERED. 



A number of unfavorable conditions was encountered during the pros- 

 ecution of the experiments. The water supply was from a stagnant 

 pond. The water had been greatly improved by the application of lime 

 a few days before the experiment was made, but it was still black and 

 putrid, emitting a nauseating stench. 



The strike-pan used was quite unsuitable for boiling to grain. Its 

 base was once the bottom of a much smaller pan, and a shelf several 

 inches deep had been added to support the enlarged top. All the large 

 steam-coils were above this shelf, and it took eight hours to bring the 

 contents of the pan above this point. We had no sugar-boiler, but my 

 assistant, Mr. G. L. Spencer, took charge of the pan and did remarkably 

 well. 



The sugar dried slowly in the centrifugals. These were not well set 

 and could not be run at a very high speed on account of shaking. 



It took nearly forty-eight hours with three machines to dry the sugar 

 from the 83.25 tons. 



This difficulty in drying was due either 



(1) To the process of diffusion; (2) to the process of carbonatatiou ; 

 (3) to the fine grain produced in boiling ; (4) or to the poor quality of 

 the cane. 



Which one of these causes was most potent only future experiments 

 will decide. I am not wise enough to place it, as has already been done 

 by some premature critics, on one of them alone. 



It seems most reasonable to suppose, however, that the poor quality 

 of the cane and the extreme fineness of the crystals were the chief 

 causes of the difficulty mentioned. The process of carbonatation has 

 been practiced for ten years in Java on mill juices and no complaint has 

 ever been heard of difficulty in purging the sugar. With the fresh, 

 ripe canes of Louisiana worked promptly as they come from the field, 

 and with the juice in the hands of an experienced sugar-boiler, I do not 

 believe this difficulty would be encountered. 



With the improvements in the process of carbonatation already pointed 

 out iii the discussion of the experiments with sorghum even better re- 

 sults may be expected. 



