XII, c, 4 Brown, Merrill and Yates: Volcano Island 207 
an important effect on the revegetation. Cox gives an analy- 
sis of ash thrown out by the eruption of 1911. This analysis 
shows nearly 5 per cent of material readily soluble in water, 
including 0.3 per cent sulphuric anhydride (SO 3 ) and 0.74 per 
cent chlorine. This would indicate that such ash would not form 
soil favorable for plants until after the water-soluble material 
had been leached out to a very considerable extent. 
Shortly after the eruption the surface of the crater lake was 
very much lower than at present and had streams of water flow- 
ing into it. Cox gives an analysis of the water of one of these 
Table III. — Analyses of water of Taal Crater, Lake Bombon, and spring' 
at Anibulong. 
[Numbers give parts per million.] 
Source. 
Spring at 
Ambu- 
long at 
northeast 
corner of 
Lake 
Bombon 
(1917). a 
Lake Bombon 
(1917). 
Crater 
Lake 
(1917). b 
Hot stream 
flowing into 
Crater 
Lake in 
(1911). c 
Near 
Ambu- 
long. a 
Near 
Volcano 
Island, b 
Total solids by evaporation 
370.0 
1,220.0 
1 , 540. 0 
40. 000. 0 
1.02 
4.6 
0. 0147 N 
0.0069 N 
Silica (SiOz).— 
72.0 
18.0 
10.0 
410.0 
710.8 
Iron and aluminum oxides FezOa+AlzOs 
2.0 
2.8 
2.0 
360.0 
Iron (Fe), total.. 
1.4 
0.24 
0. 14 
136.0 
172.0 
310.0 
79.9 
Aluminum (Al) . 
trace 
1.3 
.96 
86.0 
26.1 
Calcium (Ca) . 
41.0 
69.0 
64.0 
860.0 
556.8 
Magrnesium (Mg) 
120.0 
400.0 
50.0 
2. 650. 0 
909.3 
Sodium (Na) 
9. 870. 0 
2, 584.3 
870.0 
237.4 
Chlorides (Cl) 
6.1 
410.0 
580.0 
18, 300. 00 
6,024.3 
Iodides (I) 
0.49 
Sulphates (SO4) 
23.0 
160.0 
194.0 
3,300.0 
2, 732. 0 
18.0 
Normal carbonates (as CO 3 ) 
0.0 
12.3 
24.0 
300.0 
190.0 
150.0 
‘ Analyzed by J. Gonzales-Nunez, Bureau of Science, Manila. 
’> Heise, G. W., The crater lake of Taal Volcano, Philip. Journ. Sci. A 12 (1917). 
' Cox, A. J., Philip. Joum. Sci. A 6 (1911) 96. 
streams. This analysis is copied in Table III. The water con- 
tained 1.4 per cent of dissolved material, including over 0.6 per 
cent of chlorine, 0.26 per cent of sodium, and 0.27 per cent of 
the sulphate radicle (SO 4 ). The soil from which this high- 
Cox, A. J., The composition of the fine ejecta and a few other inorganic 
factors of Taal Volcano, Philip. Journ. Sci. A 6 (1911) 93-97. 
