D. A. Wells on the Soils of the Scioto Valley. 17 
be sought for in the presence of organic matter, crenic, or apo- 
erenic acid. In the later published works of Mulder, a salt of 
CaeHi2024 (apocrenic acid) +NH:+KO+Ca0+Mg O+Fe O, 
is given as soluble in water. It is not improbable that the ex- 
tractive matter noticed, may have possessed this constitution. 
In all the soils examined, appreciable quantities of alkalies and 
phosphoric acid existed. 
In these analyses, for the first time, has the amount of organic 
matter combined with the iron and alumina been carefully esti- 
mated by itself. This organic matter is undoubtedly combined 
with the above mentioned bases as an acid, and as such may 
have an important bearing upon the fertility of a soil. In some 
of the New England soils, this acid has been ascertained by Dr. 
Hayes of Boston to be oxalic acid, and such localities as might 
be expected, were adapted to the growth of sorrels and other acid 
plants. I have tested the soils examined by me from Ohio care- 
fully for oxalates, but have not been able to detect them. What 
other acid may be present I am unable to say: the subject in this 
connection is new and requires careful investigation. 
Manganese was present in all the soils examined. Its quanti- 
tative determination, unless present in large quantities, as well as 
the separate estimation of the amount of iron, and the amount of 
alumina, soluble in acid, I consider of little or no value in a soil 
analyses. Manganese appears to be a constituent in small quan- 
tities in almost all soils, and in the waters of lakes, ponds, and 
rivers, and must undoubtedly rank among the elementary bodies 
most widely distributed. 
In the analyses of these soils, the separation, and estimation of 
the comparative value of the organic constituents has been made 
by means of alkalies. This plan seems to possess advantages 
Over that of any other. A given portion of the soil, after wash- 
ing with water and dilute acid, is digested with a small quantity 
of caustic ammonia. The organic matter rendered soluble is 
washed out, precipitated by an acid, dried at 250° F., and weighed. 
his determination it is considered shows at once the present 
value of the organic portion of the soil—in other words, how 
much organic matter is so far decomposed, or changed, as to be 
od will become available. ‘Thus if we were to represent the 
Srconp Series, Vol. XIV, No. 40.—July, 1852. 3 
