ROLL MILLS. 273 



is left in the cane after it passes tliroug;li the ordinary mill. Some who doubt 

 this base their opinion on the apparent drj-ness of ordinary bagasse, while 

 others arrive at their conclusions from experiments which, from their nature, 

 are fallacious. The fallacy lies in the high percentage of juice claimed for the 

 mills. It is probably quite correct that, by taking a few hundred, or even a few 

 thousand, pounds of cane, and passing them carefully through a good mill, such 

 high percentages may be secured; but, with the average mill, grinding in the 

 ordinary way, I have reason to believe that the percentage of juice obtained, on 

 the whole weight of the cane, is more frequently under fifty than over. 



The above estimate of loss is undoubtedly too high, but all are 

 agreed that there is a very great lo.'?s iu this operation of expressing 

 the juice. 



To illustrate this more fully, let us take the average results of the 

 analyses made in 1881 ot the sorghums during those three periods 

 \vhen the best results iu sugar were found. 



The average composition of the juices at this time was as follows, 

 and it must remembered that these canes were pas.^ed singly through a 

 mill, giving, as will be seen, excellent results in juice : 



Per cent. 



Juice expressed.. 58 57 



Sucrose iu juice 16.18 



Glucose in juice : 183 



Solids in juice 3.07 



But 21.08 per cent of the juice, the amount of total solids, is 12.35, 

 which, subtracted from the percentage of juice, leaves 46.22 per cent, 

 as the amount of water exjDressed in the juice. 



Now, the amount of water actually present in the cane at this period 

 is probably not less than 75 per cent, which would leave in the bagasse 

 28.78 per cent of the weight of the cane as water; and, since the ba- 

 gasse constitutes 41.43 per cent of the weight of the cane, there would 

 still remain iu the bagasse 69.47 per cent of its weight of water. 

 This, to the ordinary observer, would appear incredible, since the ba- 

 gasse is so generally spoken of as being perfectly dry when it passes 

 from the mill. 



It is obvious, therefore, that, since even a good mill leaves 38.37 per 

 cent of the water of the cane in the bagasse, there also remains along 

 with this water a large amount of sugar, and that this amount, if not 

 equal to that estimated above, is yet sufficiently great to demand that 

 only such mills should be used as will secure the greatest percentage 

 of juice. 



If, in the above calculation, the amount of sugar lost is in propor- 

 tion to the per cent of water remaining in the bagasse, it is clear that 

 46.22 : 28.78 :: 9.477 : 5.901 ; i. e., while, in the expressed juice there is 

 an amount of sugar equal to 9.48 per cent of the weight of the cane, 

 18 



