23 



SUGAR IN THK NODES. 



In respect of pentose sugar it may be calculated on the assumption 

 bliat all the pentose sugar present is xylose, or that it is a mixture of 

 xylose with other pentose sugars. We prefer the former assumption. 

 The quantity of pentose is therefore calculated by the formula (per 

 cent furfurol x 1.64) -i-0.88. ] 



The total quantity of furfurol in the nodes was 13.75. Of this quan- 

 tity 92.73 per cent was extracted by the sulphuric acid, viz, 12.75. Then 

 12.75 multiplied by 1.64 equals 20.91, and 20.91 divided by 0.88 equals 

 23.76. 



Adding together the dextrose and xylose the total percentage is found 

 to be 27.16. The total per cent of sugar dissolved was found to be 

 28.86. 



In this instance the quantity of sugars separately determined lacks 

 1.70 per cent of reaching the quantity determined as a whole by alka- 

 line copper solution. 



SUGAR IN THE PITH. 



The total sugars produced from the pith by hydrolysis with sulphuric 

 acid were 23.10 per cent. 



The total quantity of furfurol in the pith was 12.98 per cent, of which 

 94.22 per cent (equal to 12.23 of the weight of the substance) was 

 removed by the sulphuric acid. This is equivalent to 22.77 per cent of 

 xylose. The quantity of dextrose in the pith, ascertained by fermenta- 

 tion, was 5.40 per cent, which, added to the xylose calculated, gives 

 28.17 per cent, a quantity 5.07 per cent greater than was given by direct 

 titration as dextrose. 



SEPARATION OF CELLULOSES BY THE CHLORINATION PROCESS. 



It will be observed from the foregoing data that when the materials 

 under examination are treated successively with dilute acid and alkali 

 under pressure, about two-thirds of the total quantity is dissolved. If, 

 therefore, cellulose fiber were prepared by these methods, only about 

 33 pounds on each 100 pounds of the dry material would be secured. It 

 is evident, therefore, that a method which would give a larger yield of 

 cellulose from a commercial aspect would be more desirable. For this 

 reason determination of the available cellulose is best secured by what 

 is known as the chlorination method. This process is carried on in the 

 following way. 



About 5 grams of the finely ground material, free of water, are boiled 

 for thirty minutes with a 1 per cent sodium hydrate solution in a vessel 

 furnished with a reflux condenser. The undissolved portion is washed 

 with water on a cloth filter and pressed to remove the excess of water, 

 disintegrated, and placed in a covered beaker into which a slow stream 

 of well-washed chlorin gas is conducted. The delivery tube conveying 



Principles and Practice of Agricultural Analysis, vol. Hi, p. 587. 



