248 



FARMERS' REGISTER— GEOLOGY. 



6. Ultimate dilavion. This seems to have been 

 a thin universal mantle, coverin<i^ the earth in the 

 first ages after the deluj^e. It still remains undis- 

 turbed in the most ancient forests. But in all 

 cultivated grounds, has been intermixed with the 

 underlaying soils. In its undisturbed state, it is 

 the soil to which the word loa7n is most properly 

 applied. Alone, it is a durable and rich soil, ex- 

 cepting where sand predominates. Mixed with 

 other soils, it is always useful. 



7. Post dilavion. Near the sources of the wa- 

 ters which deposited this soil, it is always too 

 coarse and destitute of any fertilizing quality — 

 remote from these sources, it is fine and rich — 

 midway between these extremities, it is middling 

 in character. But post-diluvion is, from the na- 

 ture of its origin, exceedingly variable — every lo- 

 cality depending on the deposites from which the 

 waters flowed. 



8. jynalluvion. This kind of soil is perpetual- 

 ly forming by the disintegration of rocks, whose 

 surfaces are exposed. Its character depends en- 

 tirely on the constituents of the rock. Therefore ar- 

 gillite and argillaceous gray wacke produce by 

 disintegration, clay soils. Rubble wacke, gra- 

 nular quartz, and other quartzose rocks, produce 

 sandy soil. Hornblende rocks produce a rich in- 

 termixture.* Limestone rocks, particularly ar- 

 gillaceous limestone, as the geodiferous limerocks, 

 produce a rich calcareous and alluminous soil. 



Broken fragments of rocks disintegrate and be- 

 come soils with a degree of rapidity, directly as 

 the superficial measure of surface exposed to the 

 disintegrating agents (water, air, and variation ot" 

 temperature) is to their quantity of matter. Con- 

 sequently lands may be suddenly enriched by 

 throwing upon them limerock, hornblende rock, 

 (whether basaltic or primitive) argillite, &c. in a 

 finely pulverized state. Or they may be gradual- 

 ly and permanently enriched by scattering over 

 them broken fragments, one inch, or two inches 

 in diameter. The rock must be selected accord- 

 ing to the original components of the soil ; so as to 

 supply what appears to be deficient. Tabular spar 

 (a fragile variety of carbonate of lime, or limerock) 

 which abounds along tiie western side of Lake 

 Champlain, has recently been applied, with aston- 

 ishing success, in the finely pulverized state. In 

 the fragmented state, it had been applied for seve- 

 ral years, to great advantage. No farmer is more 

 opposed to mere speculative theory than myself; 

 but facts place the advantages of strewing soils 

 with pulverized rocks and fragments, beyond the 

 reach of speculation. 



GEOLOGICAL ANALYSIS OF SOILS. 



The chemical analysis of soils with a view to 

 detect their ultimate elements, has promised 

 much — particularly in the hands of Davy. But 



*Dr. E. James observes, (see Long's Expedition, vol 

 2. p. 402) that in the midst of the Great Desert near the 

 Rocky Mountains, where all was " brown and desolate, 

 as if recently ravaged by fire," the hills of green-stone 

 trap, which consist essentially of hornblende, were cov- 

 ered with a green turf from their basis to their summits. 

 This is a discovery of more value to agriculture than all 

 that Sir H. Davy ever made ; though to the mineralo- 

 gist and chemist they are useful. But wlio knows the 

 modest, the amiable, the excellent Edwin James ? New 

 England might be enriched by an attention to this sub- 

 ject — and would too, had Davy told us this facU 



it has, in all cases, disappointed the hopes of the 

 practical farmer, for reasons given under Fertility 

 of Sods. It is to the Geologist, not the Chemist, 

 that the practical farmer must look for instruction; 

 so far as mere soils are to be considered. The de- 

 tection and application of stimulating earths and 

 salts (as gypsum, lime, &c.) and of decomposed 

 or decomposible vegetable matters, come within 

 the provice of the chemist. 



Chemical analysis of soils, like other analysis of 

 mineral bodies, give the ultimate elements in a 

 manner which is favorable to the pursuits of the 

 student in chemistry and chemical mineralogy. 

 The complicated mixtures of soils afford an excel- 

 lent field for trial of his strength in his first essays 

 at analysis. This is, however, widely different 

 from those researches and investigations, which 

 the impatient anxiety of the farmer demands. The 

 student is pleased with results, which evince the 

 correctness of his preconceptions, and the adroit- 

 ness of his manipulations, regardless of utility. 



But those analyses, which belong exclusively to 

 the chemist, detect fugitive and variable materials, 

 which are not to be considered as a part of perma- 

 nent soil. They may be varied from year to year 

 at pleasure ; and their proportions may be calcu- 

 lated as they are artificially varied, or they may 

 be detected and estimated by the chemist after they 

 are added. As vegetable and animal matter is a 

 geological deposite, easily detected and always 

 present in a greater or less proportion, it should be 

 considered as a part of geological analysis. 



Geological analysis of soils may be made, by 

 pursuing the course of geological deposition in mi- 

 niature. That is, soils may be deposited from wa- 

 ter, in the assay glass or a common tumbler, after 

 suitable preparations, so that the proportions of 

 silex, alumine, animal and vegetable matter, wa- 

 ter of combination, and power of absorbing, may 

 be shown. These are the most important sub- 

 jects of inquiry when the object is to improve the 

 soil, or to judge of the best method of culture, or 

 of the most profitable articles to be cultivated on par- 

 ticular fields or farms. The elevation of grounds, 

 above the level of the ocean, and the degree of lati- 

 tude, are also subjects of great importance. Hum- 

 bolt's Equivalents, deduced from comparing the 

 effects of high latitudes with mountain elevations, 

 should be duly applied. 



Formula for Geological Jlnalysis of Soils. 



1. Select about one quart of soil which shall ap- 

 pear to be an average of the field. Spread it out 

 and make it as dry as it can be made by the sun's 

 heat, after thoroughly intermixing all parts of it. 



2. Pulverize it as fine as can be done by rub- 

 bing in the hands. Take half of it, and pick out, 

 by the assistance of shaking in a dish, all roots, 

 straws, &c. also all pebbles or grains over the size 

 of a common pinhead. 



3. Weigh out, of the finest of it, with accurate 

 scales, three parcels of 200 grains each. First, 

 for determining the water of combination. Se- 

 cond, for detaining the animal and vegetable mat- 

 ter. Third, for determining the silicious matter ; 

 or rather, the earthy part which does not combine 

 with water excepting by superficial attraction of 

 adhesion. The same parcel is also employed for 

 determining the Aluminous part, and the power 

 of Absorption. 



4. Heat the first parcel in a crucible, or gallipot. 



