THE COMPOSITION OF THE SUGAR CANE 15 



under 80. In Mauritius for the year 1914 the mixed juice was of 84 6 purity, 

 with an extraction of 90 8. Not dissimilar results are to be found in Peru 

 and in Cuba. At the other extreme are the results obtained in Louisiana, 

 Argentina, Egypt, and Demerara, where, with lower extractions, average 

 purities but little over 80 are found. In the last-named district the writer 

 has experienced purities at the beginning of the crop of less than 70. 



The Reducing Sugars of the Cane. The reducing sugars present in the 

 cane consist almost wholly of glucose and fructose. Both of these are 

 present as intermediate bodies used in the formation of cane sugar, and in 

 damaged and overripe cane as degradation products of the cane sugar. 

 At different stages of the plant's growth the relative quantities vary. Geer- 

 ligs, 9 and Browne and Blouin 2 have both shown that fructose is used up 

 more rapidly than glucose, and that it therefore tends to disappear. In 

 exceptional cases it may be entirely absent leaving only glucose, as was 

 observed by Went. 6 In still rarer instances the glucose in turn is com- 

 pletely assimilated, so that very occasionally canes are found with no 

 reducing sugars ; such a case has been recorded by Wiley. 10 



As the cane arrives at the mill the percentage of reducing sugars will be 

 found to vary from a minimum of 0-3 to a maximum of 2. The former is 

 found with very ripe irrigated Lahaina cane, while the latter occurs in 

 Louisiana, where the cane never becomes ripe, and in equatorial districts, 

 such as Demerara, where the crop contains material in all stages of growth. 

 The Uba cane grown in Natal is a variety characterized by a very high 

 percentage of reducing sugars. 



The Fibre of the Cane. By fibre is understood that portion of the cane 

 insoluble in water. The term corresponds to the " marc " of beet sugar- 

 houses. Browne and Blouin 2 found the fibre of Louisiana cane to be made 

 up of : 



Ash 



Fat and Wax 



Cellulose (Cross and Bevan) 



Pentosans (Furfuroids) 



Lignin (by difference) . . 



Protein 



PITH. 



per cent. 



i-68 



0-41 



49-00 



32-04 



14-93 

 1-94 



BUNDLES. 

 per cent. 



3-58 



0-72 



50-00 



28-67 



2-00 



RIND. 



per cent. 



1-64 



0-98 



51-00 



26-93 

 17-17 



2- 19 



The quantity of fibre in the cane as it reaches the mill is distinctly a varietal 

 characteristic, and is also affected by age and conditions of growth. In 

 Hawaii, for the years 1908 to 1917, the average percentage of fibre was 

 12-58, herein being included that of the trash accompanying the cane. 

 This average refers to both Lahaina and Yellow Caledonia cane, the per- 

 centages in these being respectively about 11-5 and 13-5. In Cuba, where the 

 crop is almost entirely Crystalina cane, the crop average seldom reaches 

 ii per cent., and at the beginning of the season is generally below 10 per cent. 

 In Java, for the years 1904 to 1912, the average was 11*95 per cent., and here 

 as in Hawaii the harvest is divided between two varieties, one P.O.J.ioo, 

 with a low percentage, and one Bouricius 247, with a high percentage of 

 fibre. In Mauritius, for the year 1914, the average of 34 mills was 12*0^ 

 per cent. The cane grown in sab- tropical Louisiana contains a very low 



