13 
THE COMPOSITION OF THE PINEAPPLE PLANT AS AFFECTED BY 
MANGANESE. 
Ill this investigation a number of representative plants from 
highly manganiferous soil, on the one hand, and from normal soil, 
on the other, were separated into leaves and stalk, and after becom- 
ing thoroughly air dried were subjected to analysis. The ash was 
determined by incinerating over a free flame at a temperature well 
below redness, then leaching with distilled water, according to the 
optional method of the Association of Official Agricultural Chemists 
for the determination of ash in plants. 1 The several mineral con- 
stituents were determined in samples of the ash thus obtained. It 
should be mentioned in this connection that the percentages of sul- 
phur, chlorin, and possibly phosphorus pentoxid, should not be con- 
sidered as absolute, for the reason that partial volatilization may 
have taken place. In the case of phosphorus pentoxid, a number of 
determinations were made by the use of wet methods, and results 
closely agreeing with those secured from the ash were obtained, so 
that fair accuracy is believed to have been obtained. In any event, 
the results are comparable among themselves, and since it is for this 
purpose that they are submitted, their value is not greatly impaired. 
The composition of the ash of leaves and stalk from the two classes 
of soil is recorded in the following table : 2 
Composition of pineapple leaves and stalk. 
Leaves. 
Stalk. 
5 months 
old from 
manganif- 
erous soil. 
5 months 
old from 
normal 
soil. 
18 months 
old from 
manganif- 
erous soil. 
18 months 
old from 
normal 
soil. 
5 months 
old from 
manganif- 
erous soil. 
5 months 
old from 
normal 
soil. 
18 months 
old from 
manganif- 
erous soil. 
Per cent. 
7.14 
Per cent. 
7.98 
Per cent. 
6.24 
Per cent. 
8.86 
Per cent. 
5.12 
Per cent. 
7.78 
8.49 
1.20 
5.72 
1.76 
7.36 
.40 
5.20 
.40 
2.27 
1.56 
1.72 
4.52 
1.11 
.96 
.48 
.60 
.70 
Trace. 
1.70 
7.14 
7.60 
22.97 
16.72 
2.08 
15.66 
7.91 
18.86 
14.35 
1.40 
7.00 
6.98 
22.86 
17.12 
.25 
36.42 
2.60 
16.79 
2.65 
.25 
23.87 
5.82 
24.18 
1.65 
.20 
14.36 
7.75 
32.26 
1.10 
3.57 
1.66 
2.70 
6.12 
8.86 
6.70 
2.72 
13.33 
2.70 
13.61 
3.85 
8.86 
20.99 
6.31 
16.36 
9.36 
16.81 
11.13 
18 months 
old from 
normal 
soil. 
Per cent. 
Ash I 9.94 
Ash. constituents: L 
Silica (Si0 2 ) 9.37 
Alumina (A1 2 3 ) . 2. 12 
Ferric oxid 
(Fe 2 3 ) 81 
Manganese oxid 
(M113O4) 2.41 
Lime(CaO) 9.01 
Magnesia (MgO). 5.70 
Potash (K 2 0).... 21.09 
Soda(Na 2 0) 19.48 
Phosphorus pen- 
toxid (P 2 5 )... 2.81 
Sulphur trioxid 
(S0 3 ) 2.62 
Chlorin (CI) 13.37 
Per cent. 
6.60 
2.84 
6.02 
Trace. 
12.96 
5.78 
33.01 
.60 
8.36 
22.93 
8.01 
These data show that there is a wide range of variation in the inor- 
ganic constituents of the plant. Considerable differences have been 
1 U. S. Dept. Agr., Dur. Chem. Bui. 107 (rev.), p. 238. 
'Analyses of the roots were not made, for the reason that it is very difficult to remove 
all traces of adhering soil from pineapple roots when grown in Hawaii. 
[Bull. 28] 
