254 



The Philippine Journal of Science 



Table II. — Analyses of water-soluble constituents of Taal ejecta and soils. 



[Numbers give percentages by weight of air-dried sample.] 





1911 



1917 



Ash.' 4 ! 



Ejecta. «> 



Soil from 



unvege- 



tated 



area. 



Soil from 

 grass 

 area. 





0.82 

 0.01 

 0.16 



none 

 1.61 

 1.34 



trace 

 0.30 



0.74 



0.95 

 trace 



0.32 

 none 



2.03 



1.26 

 trace 



0.60 

 none 



0.95 



0.12 

 0.03 

 3.81 



0.03 

 nil 



0.04 



























4.33 



0.11 







0.03 

 0.16 



8.75 



0.02 

 0.04 

 0.88 









i 



Apparently the two sets of analyses are not strictly com- 

 parable because of the length of time between them and because 

 of the probability that somewhat different materials were tested. 

 It is significant, however, that the amounts of chlorides, that is, 

 of the more soluble substances, are present in much smaller 

 quantities in the 1917 samples than in those of 1911, indicating 

 the extent to which leaching has taken place. Sodium and potas- 

 sium, though not quantitatively determined in the later analyses, 

 could not have been present as more than traces. The difference 

 between the two 1917 analyses is of interest and furnishes at 

 least a partial explanation for the differences in vegetation on 

 different portions of the island. The acidity and the high soluble 

 salt content, over six years after the eruption, indicate that a 

 still greater salt concentration in the crater lake may be expected. 



REFERENCES 



1. Adams, G. I. Geologic reconnaissance of southwestern Luzon, Phil. 



Journ. Sci., Sec. A (1910) <; 5, 57-116. 



2. Bacon, R. F. The waters of the crater lakes of Taal Volcano, with a 



note on some phenomena of radioactivity, ibid. (1906), 1, 433-437. 



3. Idem. The crater lakes of Taal Volcano, ibid., Sec. A (1907), 2, 115-127. 



4. Centeno, J. Estudio geologico del volcan de Taal. Madrid (1885). 



5. Cox, A. J. The composition of the fine ejecta and a few other inorganic 



factors of Taal Volcano, Phil. Journ. Sci., Sec. A (1911), 6, 93-97. 



6. Gates, F. C. The pioneer vegetation of Taal Volcano, ibid., Sec. C 



(1914), 9, 391-434. 



7. Pratt, W. E. The eruption of Taal Volcano, ibid., Sec. A (1911), 6. 



63-86. 



8. Wright, J. R., and Heise, G. W. The radioactivity of Philippine waters, 



ibid., Sec. A (1917), 12, 145. 



