i 
fe 
160 Association of American Geologists. 
made on this subject by gentlemen present. He had digested 
soils from Maine, New Hampshire, and Rhode Island, with boil- 
ing water, without discovering more than a trace of potash; 
while the method proposed by Mitscherlich of digesting the soils 
in free sulphuric acid, always gave decided indications of potash. 
He was led to infer, therefore, that the mica and other minerals 
containing potassa.were by this method decomposed. 
Mr. B. Silliman, Jr. stated, that the soil of the Nile, when 
treated according to the method of Mitscherlich, gave abundance 
of potash, but not any appreciable quantity with boiling water ; he 
was therefore led to believe that the miea, contained abundantly 
in the soil, was decomposed by the sulphuric acid. 
Resolved, That a committee be appointed to prepare a detailed 
report upon the subject of soils and mineral manures, embodying 
as well the fruits of their own investigations as the results arrived 
at by others, and that the same be presented at the next meeting. 
Drs. C. T. Jackson, Robert Rogers, Mr. M. Boyé, Dr. L. 
C. Beck, Dr. W. Horton, Mr. B. Silliman, Jun., and Prof. 
Booth, were appointed on the above committee. 
The committee appointed to prepare a plan of business, made 
a report, which was adopted, 
Prof. Mather asked for and obtained leave to defer his report 
on “ Drift,” until the next meeting of the Association; in the 
mean time he was requested to make an oral communication on 
this subject during the present meeting. 
Prof. Locke read a paper “On the Geology of some parts of 
the United States west of the Allegany Mountains.” 
In this paper the author exhibited particularly the points of agreement 
between the lead region of the upper Mississippi, and that of Derby- 
shire in England, and between the mountain limestone of Europe and 
the “cliff limestone” of the west. He showed that the two rocks agree 
in geological position, in external and chemical characters, in fossil re 
mains, and in metallic veins ; being both highly metalliferous and abound- 
ing in lead and zinc ores occupying vertical fissures. He described the 
upper, middle, and lower beds of the “ cliff limestone” of the lead regio® 
of the west as differing somewhat in characters and in fossil remains, and 
suggested the inquiry whether these three beds, together with the blue 
fossiliferous limestone which underlies them, (the probable equivalent of 
the Trenton limestone,) and the alternations of the lower magnesian lime 
stone with the saccharoid sandstone, found at Prairie du Chien, should be 
considered disti formations, ( eee a : W nn aeeent 
W UUs bY 
