76 



hectare before any improvement in the soil as regards its actual com- 

 position could be detected. This should not be construed as an argument 

 against the use of fertilizers, foi' they are undoubtedly at times of 

 great benefit, even in very fertile soils, but the way in which they act 

 and indications for their use, although the matter has been carefully 

 studied for many years in all parts of the world, are very little understood. 



Cameron ^- states the most modern views on this subject as follows : "Soil 

 chemistry is a very complex subject, into which we are just beginning to get 

 glimpses, and the supply of mineral nutrients is only one of the important details 

 in a very intricate problem. * * * It is of course patent to everyone that 

 fertilizers sometimes, in fact frequently, produce larger crop yields. Sometimes 

 the contrary is triie, but it is absolutely certain that at the present time no one 

 can, nor are there any methods available by which one can, safely predict what 

 fertilizers and how much should be used." 



It would appear, then, that the question of the extent to which fer- 

 tilizers may profitably be employed on the soils of ISTegros, or of any 

 other sugar-producing country, is largely one of bookkeeping rather than 

 of chemistry and can be determined for a given locality only by actual 

 field experiments in that locality, and by the profit-and-loss accounts of 

 the plantations on which these experiments are made. 



THE CANE or NEGROS. 

 AVERAGE COMPOSITION OF THE SUGAR CANE OF NEGROS. 



The following table is deduced from the previously quoted analyses 

 of the common purple or native cane found in four of the most im- 

 portant districts of jSTegi'OS : 



Average composition of the purple or native cane in Negros. 



District. 



Bago-- 



Pontevedra-La Carlota 



Ilog-Cabanealan 



San Carlos 



Average 



In cane. 



Average! 



weight I 



Pe' i Su- 



cane. 



1.00 

 1.14 

 0.79 

 0.76 



crose. 



Kilof!. j Percent. 



16.41 

 14.01 

 16.95 

 16.87 



Fiber. 



Per cent. 



9.80 



9.30 



9.81 



11.20 



In juice. 



Brix. 



20.49 

 17.91 

 21.18 

 21.85 



.Su- 

 crose. 



Per cent. 

 18.80 

 15. 79 

 19.30 

 19.72 



Quo- 

 tient of 

 purity. 



91.70 

 87. 99 

 91.67 

 90.19 



Re- 

 ducing 

 sugar. 



0.62 

 0.99 

 0.49 

 0.77 



0.92 



16.06 10.02 



20.35 I 18.40 I 90.38 ! 0.71 



1 1 I 



Since the purple variety is the only one grown to any extent in 

 Negros, the above represents with a fair degree of accuracy the general 

 run of sugar cane which may be encoimtered throughout the island. 

 Below are given analyses of other varieties found in Negros. They are 



"The Dynamic Viewpoint of Soils. Jour. Ind. and Eng. Ghem. (1909), 810. 



