PRELIMINARY WORK. 
The results of some preliminary experiments on three Hawaiian 
soils dealing with the various methods of preparing soil extracts with 
distilled water are presented in the following table: 
Influence of state of moisture and time of extraction on composition of the water extract 
of soils. 
[In parts per million of dry soil.] 
Length 
of ex- 
traction. 
Bicar- 
bo- 
nates 
(HC0 3 .) 
Iron 
oxid 
and 
alu- 
mina 
(Fe 2 3 
and 
A1 2 3 ). 
Phos- 
phoric 
acid 
(P 2 4 ). 
Man- 
ganese 
oxid 
(Mn 3 
4 ). 
Lime 
(CaO). 
Mag- 
nesia 
(MgO). 
Sul- 
phuric 
acid 
(S0 3 ). 
Potash 
(K 2 0). 
Soil No. 313: 
Fresh 
Air dried 
Oven dried 
Fresh 
1 hour... 
...do 
...do 
24 hours. 
...do 
...do 
7 days... 
...do 
...do 
1 hour... 
...do 
...do 
24 hours. 
...do 
...do 
7 days... 
...do 
...do 
1 hour... 
...do 
...do 
155.0 
1, 040. 
358.0 
95.6 
678.0 
246.0 
191.0 
562.0 
262.0 
97.8 
708.0 
371.0 
117.7 
651. 
228.0 
157.0 
688.0 
180.0 
140.0 
975. 
558.0 
200.0 
53.5 
8.7 
12.8 
17.8 
13.0 
19.2 
45.8 
44.5 
49.1 
38.6 
4.3 
2.03 
1.95 
2.35 
2.55 
1.74 
3.42 
2.55 
. 2.38 
3.00 
2.32 
1.94 
2.55 
17.4 
"2. 55* 
15.20 
"i5.'2" 
88.9 
2.5 
27.4 
122.2 
121.8 
197.0 
148.0 
86.8 
120.0 
96.9 
160. 5 
102.2 
56. 5 
77.2 
89.0 
77.0 
43.0 
85.0 
71.9 
47.2 
63.8 
127.6 
224.0 
194.1 
197.6 
103.2 
123.5 
206. 7 
162.0 
212.0 
62.7 
103. 
159.0 
77.6 
102.0 
126.2 
68.3 
168.0 
116.0 
14.8 
105. 2 
99.8 
39.0 
88.5 
113.5 
70.4 
76.1 
109.0 
60.2 
120.0 
119.5 
105.1 
81.5 
103.5 
55.0 
102.0 
124.0 
247.0 
120.0 
194.0 
257.2 
134.5 
199.0 
221.5 
171.0 
145.0 
114.0 
81.0 
145. 
175.6 
72.0 
131.0 
137.1 
83.8 
151.0 
137.1 
105. 5 
136.0 
133. 7 
67.2 
133.0 
155. 6 
£3. 1 
159.0 
133.0 
256.0 
143.0 
226.6 
Air dried 
Oven dried 
Fresh 
213.0 
121.0 
239.8 
Air dried 
Oven dried 
Subsoil No. 314: 
Fresh 
282.0 
61.0 
150. 5 
Air dried 
Oven dried 
142.0 
64.1 
Fresh 
43.7 
10.8 
14.8 
23.2 
6.4 
17.0 
3.04 
20.2 
11.2 
4.6 
40.5 
15.4 
10.3 
9.0 
2.32 
2.14 
2.96 
2.05 
2.14 
2.76 
.76 
1.80 
7.05 
1.37 
1.80 
3.31 
1.06 
2.02 
5.1 
30.1 
"u.s" 
17.2 
1.52 
15.70 
'"4."6" 
15.7 
""7.'6" 
29.2 
208.5 
Air dried 
Oven dried 
Fresh 
181.0 
118.0 
227.0 
Air dried 
Oven dried 
Soil No. 319: 
Fresh 
158. 2 
68.0 
142.2 
Air dried 
Oven dried 
Fresh 
278.0 
135.0 
170.8 
Air dried 
Oven dried 
p'resh 
...do 1,300.0 
...do 270.0 
7 days...! 99.0 
...do 1,280.0 
...do 485.0 
274.0 
70.5 
155.0 
Air dried 
Oven dried 
234.0 
147.0 
The soils chosen were from the Koolaupoko district, on Oahu, 
No. 313 being a sample of brown ferruginous clay soil which occurs 
widely distributed in this district. It was very dry at the time of sam- 
pling and was covered with a heavy growth of guava. No. 314 is the 
subsoil to No. 313, and No. 319 is a sample of a similar type which 
had been plowed and planted to pineapples. 
The extracts were made by treating the soils with distilled water 
in the proportion of 5 parts of the latter to 1 of the former in glass- 
stoppered bottles, shaking occasionally during the period noted in 
the table, each being shaken an equal number of times. The values 
are figured to parts per million of the oven-dry soil. Sample No. 313 
contained, originally, 18.65 per cent moisture, No. 314 19.65 per cent, 
and No. 319 30.3 per cent. 
It will be seen that in every case the air-dried soil contained the 
largest amount of soluble HC0 3 , the oven-dried sample next, and the 
fresh soil the least, regardless of the time of extraction. 
14060°— Bull. 30—13 2 
