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838
THE POPULAR SCIENCE MONTHLY.

of the Chinese loess, but it appears to be not essentially unlike that of the Rhine, which, as analyzed by Bischoff, contains a larger proportion of alumina than the samples hitherto analyzed from Nebraska. Bischoff found in four analyses of Rhine loess:

NUMBER OF ANALYSIS
1. 2. 3. 4.
Silicic acid 58.97 79.53 78.61 62.43
Alumina 9.97 18.45 15.26 7.51
Peroxide of iron 4.25 4.81 5.14
Lime 0·02 0·02 . . . . . . . .
Magnesia 0·04 0·06 0·09 0·21
Potash 0·11 1·05 3·31 1.75
Soda 0·84 1·14
Carbonate of lime. 20·16 . . . . . . . . 11·63
Carbonate of magnesia 4·21 . . . . . . . . 8·02
Loss by ignition 1·37 . . . . 1·89 2·31

Dr. Hayden, in his "Final Report on the Geology of Nebraska," gives, on page 12, two analyses of the loess from Hannibal, Missouri, made by Dr. Lytton, as follows: in one hundred parts, there were of—

No. 1. No. 2.
Silica 76·98 77·02
Alumina and peroxide of iron 11·54 12·10
Lime 3·87 3·25
Magnesia 1·68 1·63
Carbonic acid undetermine'd 2·83
Water 2·01 2·43
Total 96·17 99·26

Dr. Aughey, in his Report on the Superficial Deposits of Nebraska" (United States Geological Survey, 1874), gives the analyses of five samples of the Nebraska loess taken from widely-separated sections, showing the wonderful homogeneity of the deposit over the large area which it covers in that State—estimated at not less than fifty-eight thousand square miles. His analyses are as follows:

No. 1. No. 2. No. 3. No. 4. No. 5.
Insoluble (siliceous) matter 81·82 81·83 81·35 81·30 81·32
Ferric oxide 3·86 3·87 3·83 3·85 3·86
Alumina ·75 ·75 ·74 ·73 ·74
Lime, carbonate 6·07 6·06 6·03 6·05 6·09
Lime, phosph'te 3·58 3·59 3·58 3·57 3·59
Magnesia, carbonate 1·29 1·28 1·31 1·31 1·29
Potassa ·27 ·29 ·35 ·34 ·32
Soda ·15 ·16 ·14 ·16 ·16
Organic matter 1·07 1·06 1·05 1·06 1·06
Moisture 1·09 1·08 1·09 1·08 1·09
Loss in analysis ·59 ·54 ·53 ·55 ·47
Total 100·00 100·00 100·00 100·00 100·00

It will be seen from these several analyses that the loess of the Rhine and that of the Republican and the upper and lower Missouri are not chemically dissimilar. The latter is thoroughly homogeneous and of uniform color from whatever depth taken.

Dr. Aughey says: "I have compared many specimens taken three hundred miles apart, and from the top and bottom of the deposits, and no difference could be detected by the eye, or by chemical analysis. Over eighty per cent of this deposit is finely-comminuted silica. ... So fine, indeed, are the particles of silica that its true character can alone be detected by analysis or under the microscope." The tendency, noted by Mr. Williams, in the Chinese loess to crystallize spontaneously, and form the cylindrical and spherical concretions which the Chinese call "ginger-stones," is also noticeable over all the loess-regions of the West. Wherever the sod is broken or the earth freshly disturbed from any cause, whether by the plow, or "prairie-dogs," these "ginger-stones" literally cover the ground. This feature is presumably due to the richness of the soil in the phosphates and carbonates of lime, which constitute about one tenth of the entire mass.

In their structural as well as chemical characteristics our Western loess-beds seem to be identical with those of China. They present, also, the same striking peculiarities of landscape-contour, erosion-products, and surpassing fertility, so well described by Mr. Williams. The unique and often exceedingly fantastic forms assumed by the loess-bluffs wherever they have been subject to erosion, as along the Missouri and lower Platte, have long excited the curiosity of tourists. Indeed, so quaint and striking are many of these natural carvings—now stately and now grotesque—that it is not easy on first acquaintance to accept them as the products of natural causes merely, and not rather as the gigantic labors of past generations. In point of architectural adaptability, too, these Nebraska bluffs are the fellows of their Chinese congeners, and fulfill the same generous function of affording cheap and healthful domiciles to whomsoever will carve out their homes in them. Many are the happy and well-to do families, scattered over these fertile regions—especially in Nebraska, Dakota, and Southwestern Minnesota—who have known no other home since "coming West" than the smoothly-hewed walls of the facile loess. Nor, for ends of comfort, cleanliness, or health, do they need to seek better homes only at the behest of taste or fashion; though, as wealth increases, the American squatter, unlike the Mongolian, soon builds for himself a more pretentious dwelling, and converts his old home into a stable or piggery. I have sometimes had occasion to seek shelter from a storm in one of these "dug-outs," and in traveling have often spent a night in them, and can testify as to the excellent quarters they afford for both man and beast. Like the "adobe" houses of the Mexicans and Pueblo Indians, they