THE COMPOSITION OF THE FINE EJECTA AND A FEW 

 OTHER INORGANIC FACTORS OF TAAL VOLCANO. 



By Alvin J. Cox. 



{From the Laboratoi-y of General, Inorganic and Physical Chemistry, Bureau of 



Science, Manila, P. I.) 



In the recent activity of Taal Volcano which began on January 27 

 and gradually increased in intensity until the explosion which took place 

 about 2 o'clock on the morning of January 30, 1911, mud or "ash'' was 

 thrown out and spread in different depths oA'er an area of more than 

 2,000 square kilometers. 



Two samples of these ejecta were collected soon after the eruption, 

 air-dried, and analyzed. The results are given in Table I, and in parallel 

 columns I have tabulated some of my former analyses of volcanic tuff 

 from various sources, to show the similarity. The first column of Table 

 I gives the analysis of a sample of the finest "ash" collected on the upper 

 southem slope of the volcano ; the second that of the same sample cal- 

 culated as free from readily soluble matter and moisture ; the third 

 represents the area on the mainland over which the mud was distrib- 

 uted to a thickness of about 1 centimeter and beyond the devastated 

 region (See Map, fig. 1, in the article by Wallace E. Pratt) ; the fourth 

 column gives the analysis of the same sample calculated as free from 

 readily soluble matter and moisture; the fifth, sixth, seventh, and eighth 

 give figures for tuff from Manila, Guadahipe, and Majaijai respectively. 



93 



