13 



The diffusion battery consists of twelve cells, arranged in a circle. 

 The nominal capacity is 25 tons in twenty-four hours, though with 

 rapid cutting a capacity of 1.6 tons per hour has been exceeded. 



From the diffusion battery the juice passes to the clarifiers of the 

 construction ordinarily employed in Louisiana. The skimmings were 

 measured and rejected, though at the first of the experimental work 

 they were returned to the diffusion battery. 



The clarified juice was concentrated in a triple-effect apparatus to a 

 sirup of 54.3 Brix (30 Baum<). This apparatus was provided with 

 heating tubes of small diameter, the steam passing through the tubes. 

 Attention is especially called to this arrangement of the heating sur- 

 face, since it was noticeable that the tubes remained clean and free from 

 scales. From the triple effect the sirup was pumped through a cooler 

 to the precipitation tanks. These tanks are 4 feet 6 inches in diameter 

 and 10 feet deep. Each tank was provided with a connection, through 

 a pump, with the filter presses ; also an outlet was arranged for draw- 

 ing off the clear sirup after the subsidence of the matters precipitated 

 by the alcohol. The filter-press pump was also arranged for pumping 

 a current of air into the tank for the purpose of thoroughly mixing its 

 contents. 



Experiments were made to ascertain the quantity of alcohol required 

 for the precipitation of the gums. Practice soon demonstrated that 

 with a sirup of 54.3 Brix a volume of alcohol of 90 per cent (by weight), 

 equal to that of the sirup, was sufficient to obtain a rapid deposition of 

 the gums. It was further shown that under these conditions the mix- 

 ture could easily be filter-pressed, the press yielding firm, hard cakes of 

 gum, which are readily removed from the cloths, leaving the latter in 

 excellent condition for further work. In successful filter-press work in 

 any branch of sugar manufacture it is essential that the removal of the 

 press cake shall leave the cloths free from adhering precipitate. As 

 may be seen from the above statements, this condition and all others 

 for good filter-press work were realized. It seems certainly marvelous 

 that sirup can be made to filter-press as easily and with as good results 

 as the skimmings in a cane-sugar house. 



In the work at the Medicine Lodge Experiment Station the clear 

 sirup was drawn off from above the precipitate and the "tank bottoms" 

 containing the precipitate were sent to the press. This method was 

 adopted for convenience in keeping each set of experiments separate. 



The clear sirup obtained by decantation and the filtrate from the 

 press were united and pumped to the distilling apparatus for the re- 

 covery of the alcohol. The sirup, freed from alcohol, was passed 

 through the usual sugar-house processes of granulation in the vacuum 

 pan and purging in the centrifugals. 



The distilling apparatus employed in these experiments is of the 

 continuous type common in Europe. It consists of a " beer still " (Fig. 1) 

 provided with a number of chambers fitted with perforated plates and 



