380 



The Philippine Journal of Science 



191S 



Toward the end of the period of flow, the percentage of sucrose 

 and the purity decrease. Table I shows the sucrose content 

 of nipa sap collected in Bulacan Province on September 15, 1912. 

 The samples were collected in polariscope tubes hung on the 

 palms and polarized directly. The per cent sucrose is calculated 

 from the polarization, assuming an apparent purity of 90. The 

 error thus introduced is slight, as shown by experience. 



Table I. — Per cent sucrose in various samples of nipa sap from 99 individual 

 palms. Collected in the Bulacan region, September 15, 1912.* 



Sample No. 



North of 



San Este- 



ban. 



South- 

 east of 

 San Este- 

 ban. 



Guagua. 



South of 



San Este- 



ban. 



Consuelo. 



Sapa 

 Cauayan. 



Hagonoy. 



1 



14.3 

 15.8 

 15.5 

 12.8 

 16.8 

 15.2 

 15.3 

 15.4 

 15.4 



15.9 

 13.7 



15.7 

 13.6 



15.6 



15.6 

 17.5 

 15.6 

 17.1 

 16.2 

 17.7 

 17.3 

 16.0 

 17.7 

 17.4 

 16.8 

 16.5 

 16.7 

 17.8 

 14.7 

 16.8 

 17.4 

 17.1 

 17.8 



11.6 

 10.1 

 13.3 

 10.9 

 10.2 

 13.5 

 11.1 

 12.2 

 10.5 

 10.7 

 10.8 

 11.5 

 11.2 

 11.2 

 13.9 

 11.5 

 8.4 

 10.8 

 11.9 

 11.1 

 12.2 

 12.8 



12.2 

 10.6 

 11.8 

 12.5 

 13.1 

 13.5 

 16.2 

 15.2 

 14.5 

 17.4 

 12.5 



14.8 

 14.7 

 15.8 

 17.3 

 12.9 

 14.1 

 15.6 

 13.3 

 16.3 

 14.4 

 15.2 



2 



3 



14. 3 14. 7 



4 



12.9 

 13.6 

 15.6 

 15.7 

 13.6 

 15.7 

 14.6 

 16.0 

 16.4 

 16.9 

 15.8 



15.0 

 15.9 

 15.3 

 14.6 

 12.7 

 14.6 

 15.1 



5 





7. 



8 



9 



10 



11 





12 







13 .. 











14 











15.. 





14.1 









16 





13.9 









17 











18 













19 













20 













21 . 











22 















Average 















15.2 



14.9 



14.7 



16.8 



11.4 



13.6 



14.8 



" Determinations by E. R. Dovey. 



Table II shows the total sugar and volume of juice per twenty- 

 four Lours from 20 palms with flower stalks of various lengths. 

 As the stalks are sliced daily when flowing, they become shorter 

 as the season advances. These samples represent sap flowing 

 near the end of an abnormal season during which lack of rain 

 and other climatic conditions rendered the supply of tuba very 

 scant and of poor quality. 



