106 FLORIDA GEOLOGICAL SURVEY—THIRD ANNUAL REPORT. 
The oxidizing processes are the most rapid near the surface, 
especially above the underground water level, and H2S derived 
from this source probably supplies relatively shallow, rather than 
deep waters. 
The formation of H2S by steam passing over sulphur which 
occurs in connection with volcanoes, may be dismissed in consid¬ 
ering the sulphur waters of Florida, since Florida has no volcanoes 
and no indications of volcanic activity. 
SULPHUR WATER NOT EVIDENCE OF BEDS OF SULPHUR. 
There is a widespread belief that the presence of sulphur water 
must necessarily indicate the existence of beds of the mineral sul¬ 
phur. This conclusion does not follow. The probable sources 
of the sulphur in sulphur waters as indicated above is organic 
matter together with metallic sulphates and sulphides scattered 
thiough sedimentary rocks. 
SULPHUR DEPOSITS FORMED FROM HYDROGEN SULPHIDE- 
As stated in the last paragraph, sulphur waters are not to be 
regarded as resulting from beds of pure sulphur. On the contrary, 
it is probably true that these waters may, in some instances, result 
in the formation of such deposits. Hydrogen sulphide when acted 
upon in the water by oxygen breaks up, forming water and sul¬ 
phur, the reaction being Il 2 S+ 0 =H 20 +S. It is thus possible 
that H2S in the underground water, or escaping from the under¬ 
ground water, may become disassociated, forming deposits of 
pure sulphur. Such deposits of economic value have not been 
reported in Florida. It is a noteworthy fact, however, that one 
large mass of sulphur has been found underneath phosphate beds 
in Citrus County.* The formation of this mass of sulphur is prob¬ 
ably due to hydrogen sulphide. A flocculent white coating of sul¬ 
phur or a sulphur compound invariably forms around sulphur 
springs and flowing sulphur wells. 
ABSENCE OF HYDROGEN SULPHIDE FROM CERTAIN WATERS IN 
FLORIDA. 
The absence of hydrogen sulphide from the first water obtained 
from areas in which the open porous limestone is the surface forma¬ 
tion, has already been stated. It is a well-known fact that if sul¬ 
phur water is allowed to stand in the open air the gas will escape. 
^Florida Geological Survey, First Annual Report, p. 44, 1908. 
