COMPOSITION OF THE FINE EJECTA, TAAL VOLCANO. 97 



A second cause of damage to the plants may exist in the large quan- 

 tities of salts of iron which are often popularly called sulphur. Bacon 

 and others writing of the volcano have noted the great extent to which 

 the rocks are colored by a deposition of that particular iron salt which 

 gives them a red or yellow color. These deposits, which are largely 

 soluble salts of iron, occurred all over the crater island and were un- 

 questionably distributed with the mud shower. The injury to vegeta- 

 tion may be partly traceable to them.^ However, it was not to be antici- 

 pated that any large quantity of soluble iron salts would be found by 

 the time the sample arrived at the laboratory. 



* These salts give free acid by hydrolysis when in solution. 



