AND COAL-MEASURES OF IOWA. 111 
to the westerly dip of the strata, carrying the impervious argillaceous beds down, 
whilst the water filters freely through the superincumbent sandstones. 
In the neighbourhood of Portland, which is sixty-six miles by water, above the 
mouth of the Des Moines, coal is found in several places. On the north corner of 
the northwest quarter of Section 25, Township 70 north, Range 11 west, about 
thirty-five feet above low water of the Des Moines, a seam four feet thick shows 
itself, just above the bed of Doud’s Creek, resting on a bed of tenacious clay, and 
covered by the subsoil of the creek bottom; also at several other places on the 
same creek, indicating an easterly dip of ten to fifteen feet in three-quarters of a 
mile. On a branch of the same creek, this coal is again seen, covered with six feet 
of sandstone, as well as on Section 24, at the forks of the same branch, and on the 
northeast quarter of Section 25. On the northeast quarter of Section 10, Township 
70 north, Range 11 west, at a much higher elevation, is a pretty fair quality of 
coal, on Mr. Walker’s land. On the west side of the Des Moines, on the waters of 
Holeomb’s Creek, some little coal shows itself; on the same stream, also, there are 
a few licks of brackish water. 
In the bed of the Des Moines, nearly opposite Iowaville, coal is found below the 
water-level ; and two miles south of Iowaville, is a bed of coal owned by Mr. Miles. 
One and a half miles from the river is another, belonging to Mr. Campbell; besides 
which, it occurs at many other places in the neighbourhood. 
On Section 14, Township 70 north, Range 12 west, on the farm of Mr. Jacob 
Carter, is a weak brine spring, which, with nitrate of silver, affords a white, curdy 
precipitate, insoluble in nitric acid, but soluble in ammonia, and also gives with 
chloride of barium a white precipitate, only partially soluble in nitric acid. Acetate 
of lead does not give a black precipitate, nor even darken the water, but yields only 
a white precipitate, consisting partly of sulphate and partly of carbonate of lead. 
Both ammonia and carbonate of ammonia give merely a white precipitate ; while 
hydrosulphuret of ammonia gives no immediate appreciable precipitate. The water 
deposits a copious brown, gelatinous, hydrated oxide of iron, mixed with a little 
carbonate, which, when dissolved by acid, strikes a deep Prussian blue with ferro- 
cyanide of potassium, and black with hydrosulphuret of ammonia; indeed, this 
latter reagent gives an instantaneous blackness when merely dropped on the brown 
deposit as it settles from the water. Ten or twelve other brine springs occur on 
Section 17, Township 70 north, Range 12 west, which give similar reactions with 
chemical reagents. Of those which I tested, that on Section 17, Township 70 north, 
Range 12 west, gave the most copious precipitate with nitrate of silver; but none 
of them can be regarded as strong brines. In the Introduction, I have given the 
reasons why I considered it doubtful whether, by boring, a profitable brine could be 
procured. 
The constituents of these waters are: chloride of sodium; chloride of magne- 
sium; bicarbonate of iron ;* bicarbonate of lime; sulphate of soda; sulphate of 
magnesia; with perhaps some other ingredients in small proportion, as bromides 
and iodides; but not having received a supply of the water, as I expected, to submit 
it to rigid analysis in my laboratory, I am not able at present to give any more 
definite information regarding these saline springs. 
* Precipitated almost as soon as the water reaches the atmosphere. 
