446 
Journal of Agricultural Research 
Vol. XXIX, No. 9 
Table IV .—Chemical composition of Madison dustfalls compared with that of 
foreign dustfalls 
Percentages 
Constituents 
A * 
B 
C 
D 
E 
F 
G 
Si0 2 .... 
71. 73 
67.20 
53.68 
45. 94 
45. 40 
41. 43 
36. 32 
AI 2 O 3 _ 
7. 85 
13. 71 
18. 44 
18. 35 
19. 97 
10. 38 
16.35 
Fe 2 C>3..... 
FeO_____ 
} 3.93 
2.17 
| 6.54 
6. 57 
7.03 
9.19 
6.08 
MgO__ 
1.00 
1. 76 
1. 52 
1.86 
3.13 
.92 
2. 21 
CaO__ 
1.83 
1.74 
.95 
8.64 
6.50 
14.10 
6.24 
Na 2 0_ 
1.17 
2.11 
1. 67 
1.16 
2.61 
1.66 
2.59 
K 2 0__ 
2.11 
2.30 
2.58 
2.30 
2.07 
1. 58 
2. 72 
H 2 0___ _ 
4. 95 
3. 22 
C0 2 ___ . 
6.10 
3. 46 
8.45 
3.68 
Ti0 2 _ . 
.49 
. 52 
P 2 O 5 _ 
. 17 
. 15 
.20 
MnO_ 
.21 
.38 
N__ 
.37 
.39 
. 16 
.16 
Ignition__ 
3. 61 
5. 62 
14.60 
6. 73 
8.19 
5.14 
13.44 
Total_ 
99. 42 
101.28 
99. 98 
100.00 
99. 73 
99. 00 
100.00 
°A.—-Dustfall at Madison, Feb. 13, 1923. 
B. —Dustfall at Madison, Mar. 19, 1920 (12, p. 349). 
C. —Dustfall at Otakaia, New Zealand, Nov. 14, 1902, which came about 1,500 miles from Australia (6). 
D. —Dust in “red rain” fall at Lamberhurst, England, Feb. 22, 1903; 2.19 per cent of organic carbon in¬ 
cluded in total (10, p. 54). 
E. —Dustfall at Naples, Italy, Mar. 10,1901. (7, p. 157.) 
F. —Dustfall at Naples, Italy, Feb. 25, 1879, analysis by Scacchi, quoted by Palmeri (7, p. 161); 4.16 per 
•cent of organic material and 1.39 per cent “loss” included in total. 
G. —Dustfall at Taormina, Sicily, Mar. 19, 1901. The fall amounted to 5K tons per square mile (10, p. 
M2); 9.89 per cent of organic carbon and 0.32 per cent of CoO included in total. 
Table V.— Chemical composition of Mississippi Valley loess compared with 
that of Madison dustfalls 
Percentages 
Constituents 
A 0 
B 
0 
' D 
1 
1 
E 
F 
G 
H 
Si0 2 _ 
79. 77 
74.46 
72.68 
71. 73 
70.86 
70.11 
67.20 
64.61 
A1 2 C>3_ 
9.95 
12.26 
12.03 
7.85 
} 3.93 
8.91 
14. 25 
13. 71 
10 '64 
Fe 2 03 __ 
3. 39 
3.25 
3. 53 
J 2.97 
/ 4.02 
} 2.17 
/ 2.61 
FeO 
. 12 
.96 
\ . 10 
\ .51 
MgO.. 
.26 
1.12 
1.11 
1.00 
3.12 
1. 32 
1. 76 
3.69 
•CaO_ 
.67 
1.69 
1. 59 
1.83 
4.13 
1. 53 
1. 74 
5.41 
Na 2 0.. 
1.08 
1.43 
1. 68 
1.17 
1.69 
1.09 
2.11 
1.35 
K 2 0_ 
2. 05 
1. 83 
2.13 
2.11 
1.18 
2. 03 
2. 30 
2.06 
H 2 0_ 
2. 55 
2.70 
2.50 j 
4.95 
1.10 
2. 48 
3. 22 
2.05 
C0 2 . 
.49 
.39 
4. 70 
6.31 
Ti0 2 
.70 
. 14 
.72 
.49 
.59 
.52 
.40 
P 2 O 5 
.09 
.23 ! 
. 17 
.40 
. 15 
.06 
MnO 
.02 
.06 | 
.21 
.28 
.38 
.05 
Total_ 
100. 42 
1 
99. 83 
100.22 
99. 42 
99.98 
100. 33 
101. 28 
100.06 
« A.—Loess, Terre Haute, Ind. (8, p. 562). 
B. —Loess, Kansas City, Mo. (1, p. 282). 0.12 organic carbon, 0.06 SO 3 and 0.05 Cl included in total. 
C. —Loess, Dubuque, Iowa (1, p. 282). 0.51 SO 3 , 0.09 organic carbon, and 0.01 Cl included in total. 
D—Dustfall at Madison, Wis., Feb. 13,1923. 3.61 organic carbon'and CO 2 and 0.37 N included in total. 
E.—Loess, Mt. Vernon, Iowa (4). 
F—Loess, Kansas City, Mo. (5, p. 94). 3.50 ignition loss included in total. 
G.—Dustfall at Madison, Wis., March 19, 1920 (12, p. 349). 5.62 ignition loss and 0.39 N included in 
total. 
H—Loess, Galena, Ill. (1, p. 282). 0.13 organic carbon, 0.11 SO 3 and 0.07 Cl included in total. 
The dustfall at Madison on Febru¬ 
ary 13, 1923, is the most siliceous on 
record, although some dustfalls in 
Europe derived from the Sahara desert 
are said to reach a maximum of 73.45 
per cent of silica. 
European dustfalls are often very 
red, producing the so-called “red 
rain,” or “rain of blood.” This is due 
to complete oxidation of the iron, and 
is in marked contrast to the incom¬ 
plete oxidation and gray color of the 
