INORGANIC COMPOSITION OF SOME AMERICAN SOILS. 3 
the following memoranda are taken concerning the distribution of 
the rarer elements in igneous rocks. Only those elements reported 
in the present work are considered. 
BARIUM. 
This element is found in feldspathic rocks and appears to be asso- 
ciated in some quantitative way with potassium. The occurrence of 
barium in soils has been very thoroughly treated by Failyer. 1 It 
was found wherever sought in all soils of the Great Plains, in amounts 
from 0.02 to 0.11 per cent expressed as the oxide. It was further 
qualitatively shown to be present in many soils east of the Mississippi. 
Of all the soils examined only two, the Orangeburg fine sandy loam 
and Houston clay, from Texas and Alabama, respectively, failed to 
give the barium reaction in the samples tested. 
CAESIUM. 
This is the rarest of the alkalies. It has been found in spring water 
and reported in the ash of the sugar beet by Von Lipman, 2 and Vernad- 
ski 3 has found spectroscopic traces in feldspars and micas, so that in 
very small quantities at least it may be expected in rocks and soils. 
CHROMIUM. 
This element occurs more especially in the ferromagnesian rocks, 
though in small amounts. It has been reported in soils and the ash 
of plants. 
copper. 
Copper appears to be widely distributed and to be more abundant 
in the basic rocks. However, Hillebrand points out that there is 
great danger of contamination during the process of analysis by copper 
from numerous copper utensils employed. It has been reported 
in a number of plants to which it must have come from the soil. 
LITHIUM. 
Washington states that lithium often occurs in rocks high in 
sodium. It is widely distributed but seldom occurs in more than 
spectroscopic traces, except in its characteristic minerals. 
MANGANESE. 
Manganese is hardly to be considered as a rare element, though 
it is present in rocks and soils in small amounts. It is widely distrib- 
uted. The analytical results for manganese in soils hitherto reported 
are probably inaccurate. 
i Bui. 72, Bureau of Soils, U. S. Dept. Agriculture (1910). ^Bul. Acad. St. Petersburg, 821 (1909). 
2 Ber., 21, 3492(1889). 
