WATER SUPPLY OF EASTERN AND SOUTHERN FLORIDA. 
137 
earth, upon pyrite or marcasite, produces sodium sulphide. The 
reaction given by him is as follows: (L. C. page 1107.) 
8FeS2-f-15Na2C03=4Fe203+14Na2S+Na2S203-|-15C02. 
It is a well-known fact that the carbon dioxide, which unites 
with water to form carbonic acid, is abundant in the deep waters, 
especially in the limestone formations; the pressure existing at 
considerable depth enabling the water to hold great quantities of 
carbonic acid. The series of reactions given by Stokes accounts 
for the presence of alkali sulphides in solution in the deep waters. 
It may be added that all sulphides are soluble, to some extent, in 
water and, in that condition, may be acted upon by carbonic acid.f 
The partial oxidation of sulphides is, according to Van Hise, 
a possible additional method of formation of hydrogen sulphide, 
the reaction being as follows: (L. C. p. 1113.) 
3FeS2-|-4H20V40=Fe304-|-4H2S+2S02. 
The oxidizing processes are the most rapid near the surface, 
especially above the underground water level, and H 2 S derived 
from this source, probably, supplies relatively shallow rather than 
deep waters. 
The formation of H 2 S by steam passing over sulphur, which 
occurs in connection with volcanoes, may be dismissed in consider¬ 
ing 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 
sulphur. 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 
through sedimentary rocks. 
fInorganic Chemistry. International Library of Technology. Sec. 
12, p. 11. 
