viii, a, 6 Pratt et al.: Nipa Palm 387 



tuquils must be combined for transportation to the mill, and a 

 few rich in enzyme might thus contaminate a large collection. 



Laboratory experiments with tissues of nipa palm showed that 

 the presence of a small amount of sulphite was sufficient effec- 

 tively to destroy the enzyme. The results of these experiments 

 led us tft believe that the addition of sulphite, in small amount, 

 to the lime cream before placing it in the tuquils would result 

 in better preservation of the tuba. The actual results obtained 

 by this means exceeded our expectations, and appear to solve 

 the question of preserving nipa juice. A long series of further 

 studies in the swamps demonstrated that sap collected from very 

 short stems producing only a few hundred cubic centimeters of 

 juice in twenty-four hours could be collected and preserved for 

 over ten days when sulphite had been added to the lime cream in 

 the tuquil. Sap flowing from palms of this type always gave a 

 strong positive test for peroxidase. 



EXPERIMENTS IN BULACAN PROVINCE 



A number of samples were collected on January 25, 1913, in 

 Hagonoy, Bulacan Province, at the extreme end of the season 

 when the flower stalks were short and had nearly ceased flow- 

 ing. Small samples were first collected in clean glass bottles and 

 analyzed to show the composition of the fresh sap and its rate of 

 flow. Tuquils were then cleaned, lined with lime cream, and 

 placed on the palms. The collections were made twenty-four 

 hours later and analyzed at once. All these tuquils showed acid 

 layers of juice at the top and much frothing due to fermentation. 

 Tuquils were then lined with lime cream containing a small 

 amount of sodium bisulphite and placed on the same palms. 

 These samples were also collected after twenty-four hours and 

 analyzed. A much smaller percentage showed acid tuba and 

 foaming, and the juice was nearly colorless in every case. None 

 of the first series collected with lime alone contained sucrose 

 after further standing for one day, while those in which sulphite 

 had also been used showed no further change. The latter were 

 then combined to form a composite sample, that was transported 

 to Manila and carbonated to faint alkalinity. The precipitate 

 of carbonate was removed, leaving a bright juice of slightly 

 yellow color and high purity. Tables IX, X, and XI show the 

 results of these analyses. 



