ee 
Geology of Upper Illinois. 157 
ing and evaporating fluids. It will also give rise to a cdke of 
amedium quality, the presence of iron-pyrites not being found so 
considerable as to interfere with its employment by the black- 
smiths of the country, who prefer it indeed in their work, to 
charcoal. 
Mineral Springs and Salt. 
Sulphureons and saline waters appear to be of frequent occur- 
rence in the region of the coal-deposit above described. Copious 
springs occur at and near Ottawa, particularly on the Illinois bot- 
toms in the vicinity of Buffalo rock. Others again exist in the 
bed of the Big Vermilion, at Vermilionville, and near the mouth 
of the Mazon river. 
The springs on section twenty three (H,) have already been 
alluded to. The two which come to the surface near together, 
and by the road-side, may be denominated saline waters. Their 
temperature was apparently above that of other springs in the vi- 
cinity, and decidedly superior to the mean temperature of the cli- 
mate. No odor of sulphuretted hydrogen is evolved from either 
of them, nor do they blacken a solution of acetate of lead. The 
application of the usual tests, proved them to contain the follow- 
ing principles :— 
Carbonic acid. 
Nitrogen. 
Super-carbonate of lime. 
Bi-carbonate of soda. 
Chloride of sodium. 
a of calcium. 
. of magnesium. 
epee of lime. 
of magnesia. 
. of soda. 
The spring issuing from the sandstone ieyein, nearly on the 
bank of the Illinois, is a strong sulphureous water ; and in addi- 
tion to the above enumerated ingredients, contains free sulphur- 
etted hydrogen and the hydro-sulphuret of sodium. 
Both these springs were tested for iodine and bromine, with- 
out discovering either of these substances; although the exam- 
ination was made on less than a gallon of water. If these prin- 
ciples are present therefore, their proportion must be inconsidera- 
ble, compared to the other ingredients. 
