342 DATE SUGAR INDUSTRY IN BENGAL. 



Formalin. This seems to be very satisfactory. It was noted 

 that formalin had more marked effects when the juice was first filtered 

 through filter paper, than when it was simply strained through cloth. 

 Thus in No. II the juice kept in a remarkable manner with no sign 

 of change for 12 days and only 3 c.c. of- 40 per cent, formalin were 

 added to 700 c.c. of juice. It might be remarked here that formalin 

 was observed to bleach the faint brownish colouration which a quite 

 fresh date juice has. The other four experiments with formalin 

 did not give as great an effect but the formalin seems to have checked 

 the alcoholic fermentation only allowing the inversion of the 

 sucrose. 



Dry basic lead acetate in experiment No. VIII seems to have kept 

 juice fairly well for some days ; but we should have doubtless ob- 

 tained much better results had we filtered off the lead precipitate. 

 It was unfortunate that the juice could not be examined for some 

 days after the 12th owing to travelling. Dry basic lead acetate has 

 been previously recommended for use in storing juices. In a series of 

 experiments described by Spencer 1 a sample of cane juice preserved 

 with this reagent gave the following percentages of sucrose after 

 successive intervals of 24 hours except where otherwise stated : 

 16-98, 16'96, 16-98, 16'96, 16'98, 16'98 (interval 48 hours), 16'98 

 (interval 48 hours), 16*96; after a further interval of 5 days there 

 were indications of fermentation. 



Our experiments are not so favourable to the use of dry basic 

 lead acetate, but it is possible we did not use a sufficiency of the 

 reagent. It might be of interest here to mention that on several 

 occasions in camp juices which had been clarified with basic lead 

 acetate and analysed one day were found unchanged on analysis the 

 following day. Thus one may take samples of juice in the field 

 and add dry basic lead acetate on the spot and there need be no fear 

 of their undergoing change if one is delayed by an hour or two in 

 carrying out the analysis. 



Handbook for Sugar Manufacturers, p. 85, 



