104 FLORIDA GEOLOGICAL SURVEY—THIRD ANNUAL REPORT. 
beyond this depth. Most of the water, however, returns to the 
surface after a comparatively short underground course, only a 
small part of it reaching to this great depth. 
HYDROGEN SULPHIDE IN UNDERGROUND WATER. 
The underground water of Florida is very generally impregnat¬ 
ed with hydrogen sulphide (H2S) also known as sulphuretted hy¬ 
drogen, and hydro-sulphuric acid. Water containing hydrogen 
sulphide is commonly known as “sulphur water.” Sulphur water 
is especially characteristic of the areas of artesian flow. In those 
sections in which open porous limestone is the surface formation, 
hydrogen sulphide is usually absent from the first water encoun¬ 
tered, although even here it is found to exist in the water from the 
deep wells and in some springs. 
Source:—Hydrogen sulphide may originate in nature in any 
one of several ways. The following have been suggested: (1) 
The decay of organic matter containing sulphur; (2) the reaction 
of organic matter upon sulphides or sulphates; (3) the reaction 
of acids upon sulphides; (4) partial oxidization of sulphides; (5) 
steam passing over sulphur. 
The decay of organic matter is an obvious source of hydrogen 
sulphide in the underground waters of Florida. Chemical analysis 
shows that sulphur is very generally present in Florida soils,* and 
apparently invariably present in muck soils. Analyses of samples 
of peat which is, like muck, a vegetable accumulation, will be found 
in the following paper on peat deposits in this volume. The 
amount of sulphur in the Florida peat in the dried samples varies 
from less than 1% to over 4%. 
Hydrogen sulphide is formed in connection with the decay of 
eggs. In this case the albumen of the egg, according to Ostwald, 
contains the sulphur.! H2S is also found escaping from sewer 
drains and cesspools, and is formed during the decomposition both 
of animal and vegetable substances. The, H2S occurring in shal¬ 
low springs from marsh lands is doubtless supplied largely from 
organic material. 
The sulphur in soils is probably often present as sulphates. 
Thorpe' states that the decay of organic matter in contact with 
sulphates results in the formation of H2S.J The reaction in this 
^Bulletin 43, Florida State Experiment Station, pp. 653, 657, 659, 1897. 
fOstwald, Principles of Inorganic Chemistry, page 274, 1904. 
^Dictionary of Chemistry, Vol. Ill, p. 697, 1900. 
