386 DATE SUGAR INDUSTRY IN BENGAL. 



The cultivator says he does not clean his pans because after putting 

 water in them they are liable to crack on the fire. Yet in the case 

 of boiling the sugarcane juice, when earthen pans are used and clean- 

 ed daily with water, the pans seldom crack. 



V. METHOD OF TAPPING. 



The main drawback to the use of date juice for sugar manufac- 

 ture is its high glucose ratio. The writer has shewn however that 

 the juice as it exudes from a freshly cut surface of the tree contains 

 only sucrose and that the reducing sugars are formed subsequently 

 as a result of fermentation. If this subsequent fermentation could 

 be stopped, the industry should have a great future. It occurred 

 to us that if the trees were tapped by drilling holes into them with an 

 auger then a much higher quality of juice would be obtained for 

 there would not be such a large cut surface exposed to the air. It 

 was found however that the flow of juice from holes drilled into the 

 tree was practically negligible. Indeed, in the native process of 

 tapping it will be remembered that the sap yielding surface is not 

 cut into at once in the beginning of the season. If this is done 

 very small yields of juice only are obtained. The bark is first 

 removed and the delicate underlying tissues are exposed for some 

 time. The copious flow of juice is apparently due to excitation of 

 the tissues due to the wound. 



It seemed to us desirable to test the effect of a simple antisep- 

 tic in preserving the quality of the juice. Formalin was chosen 

 for this as it is a good disinfectant, easily obtainable and cheap. 

 The experiments on page 342 have shewn how effective the substance 

 is, in preserving date juice. In the field it is impossible to plan ex- 

 periments to shew exactly how great is its effect. The real difficulty 

 is to find two sets of trees which are yielding exactly similar juice, so 

 that one set may be treated with formalin and one remain untreated. 

 Attempts were made to select groups of trees which would give 

 juice of about the same composition. On several occasions 20 trees 

 were selected and their yields measured. Attempts were made to 

 collect these 20 trees into groups so that two groups might be obtain- 



