﻿THE CRATER OF TAAL. 117 



to the deposition of components of iron salts showing such coloration; 

 the deposits are to be found all over the volcanic island. We were 

 unable to discover any sulphur in the crater of the volcano, although 

 very perfect gypsum and alum crystals, colored to a sulphur yellow 

 by salts of iron, were everywhere vigorously growing within the crater. 

 Small fumaroles and fissures in the ground are situated all over the 

 crater areas, even on the highest points on the walls; these emit steam 

 and hot, sulphurous gases. The same class of efflorescent salt deposit 

 as is encountered on the walls surrounding the boiling crater lake is 

 encountered around the openings of many of these small vents. In 

 examining these fumaroles it was noted that steam issued from some, 

 whereas others gave off hot, sulphurous gases. No hydrogen sulphide 

 was detected in the gases issuing from the various fumaroles in and 

 around the crater, and the absence of any deposits of sulphur in the 

 crater would suggest that this gas is never present, because, in the 

 presence of the large amounts of sulphur dioxide, hydrogen sulphide, 

 were it at any time a constituent of the volcanic gases, would certainly 

 be decomposed to form sulphur. 



Specimens of water were collected as follows : (a) From the boiling 

 crater lake (Water No. 1) ; (6) from a green pool immediately to the 

 north of this boiling lake (Water No. 2) ; and (c) from the green lake 

 (Water No. 3). 



Water No. 1 is of a light grayish-green color; it is quite full of sedi- 

 ment, due to constant ebullition; its temperature is a little over 100° 

 C. ; it is very acid and possesses a strong odor of sulphur dioxide. It 

 was much lighter in color than are the other waters, because sulphur 

 dioxide is continually bubbling through the lake from which it comes, 

 thus keeping the iron salts in almost a colorless, ferrous condition. 



Water No. 2 is of a deep green color. It was collected from one of a 

 series of remarkable and formerly inaccessible pools which are found in 

 what at first sight appears to be a filled-in extension of the boiling crater 

 lake. What seems to be the northern beach of this lake consists of a 

 crust of various colored iron and aluminium salts, in which numerous, 

 small pools, 0.5 to 5 meters in diameter are encountered. These pools 

 are of different colors — yellow, blue, green, and deep red. Some are 

 boiling and are continually sending out small clouds of steam, while 

 others in the immediate neighborhood are relatively cold. The one 

 which was accessible, and from which the water which I analyzed was 

 obtained, is boiling hot. The crust between these lakes will not support 

 a man, hot water is present beneath it. It is remarkable that these pools 

 should be so different in character, as is evidenced by their different 

 colors and temperatures, when they occur in such close proximity to 

 eacli other, with only apparently a thin, soft crust separating them. In 

 fact, I was surprised to find the water of the pool which I examined to 



