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clarity of organization, more interest in the out-of-town teachers, 
systematic publication of addresses and papers — but these are 
minor flaws in an institution that represents the best interests of 
our public school system, the crowning glory of the American 
commonwealth. 
Vaughan MacCaughey, 
Secretary. 
The College of Hawaii. 
A THEORY REGARDING THE MANGANESE SOILS 
AND PINEAPPLES. 
The manganese soil of Wahiawa presents a peculiar if not 
unique problem when studied with relation to its effect upon the 
pineapple. In many cases the pineapple plants upon this soil 
are stunted in growth, are more susceptible to infection, are sickly 
in appearance and lack the healthy green color imparted by a nor- 
mal supply of chlorophyl. While it is admitted that these condi- 
tions may be brought aliout by agents other than manganese such 
as lack of drainage, root-rot, uric acid and its salts in liquid 
manures, still it is conceded that in this particular case the man- 
ganese is responsible for these unhealthy manifestations. Prac- 
tically every one who has made an investigation of this problem 
has drawn some conclusion correlating the unhealthy appearance 
of the pineapples with the manganese in the soil. 
Manganese is found widely distributed in nature, but never in 
the free state. It is found mostly in combination with oxygen 
as manganese dioxide (pyrolusite) , manganic oxide (braunite), 
and red manganese oxide (hausmanite) . There is also a man- 
ganous oxide which with the manganic oxide shows basic charac- 
teristics. This fact may account for the results obtained by W. P. 
Kelley in Press Bulletin 23, Hawaii Experiment Station, showing 
that the acidity of the manganese soils was less than adjacent 
fields containing only moderate amounts of manganese. Man- 
ganese dioxide is able to give manganous salts with the elimina- 
tion of available oxygen and it is also capable of combining with 
more basic oxides such as lime to form unstable compounds 
known as manganites. 
Kelley has found manganese in these soils equivalent to 9.74% 
mangano-manganic oxide. Analyses made in this laboratory as 
early as February, 1906, showed the manganese soils to contain 
manganese equivalent to 7.8% mangano-manganic oxide, 2.1% 
of which was combined in silicate form and the balance as higher 
oxides. 
Mr. O. Tamm, investigating complex manganese compounds of 
the hydroxy acids found that citric acid dissolved considerable 
amounts of manganous hydroxide. The oxides of manganese 
have also been shown to be soluble in acids. H. Molish has shown 
that various water plants when placed in solutions of different 
