FARMERS' REGISTER— GEOLOGY. 



247 



plained bj' referring; to other strata; unless weadmit 

 the general principle that all deposites, made after 

 the deposition of the lower part of the argil lite, con- 

 sist of fragments of the older rocks. 



The principle heretofore received then, that soils 

 depend for their constituent characters on under- 

 laying rocks, cannot be received any flxrther than 

 as applied to analluvion. All other kinds of soil 

 have characters as independent as transition or se- 

 condary rocks; and they may be classified now, 

 with as much accuracy. 



FERTILITY OF SOILS. 



1. Fertility of merely earthly soils does not de- 

 pend on their ultimate chemical elements. Pul- 

 verized emery, which is almost pure alumine, will 

 have the same influence upon vegetation as pulve- 

 rized quarts, which is nearly purely silex. Hence 

 the reason that Davy, and other distinguished che- 

 mists have disappointed agriculturists by their 

 analysis; which were founded on such mistaken 

 views. 



2. The perfection of earthly soils, without any 

 reference to animal, vegetable, or other adventiti- 

 ous matter, requires the following constituents in 

 due proportion : 1. <S7ones and j9eo6/es sufficient to 

 keep the soil open and loose. 2. Clay suliicient 

 to absorb and to hold water in a just proportion. 

 3. JF'iiie Saiul in sufficient quantities to prevent 

 the clay from baking into a compact mass, in time 

 of drought. Also to prevent its retaining so much 

 water in the winter season, as, by expansion du- 

 ring the freezing of the water, to draw the roots 

 of vegetables from the earth — called the winter- 

 killing process. 



To select a (arm for purchasing, or to improve 

 land by artificial means, without the application of 

 manures, requires particular attention to these 

 proportions. 



Vegetables receive their chief support from the 

 atmosphere; and the whole of it when they grow 

 in clean, pure, unmanured earth. Neither dry 

 sand nor baked clay will absorb the nutritious 

 gases. Duly moistened earth absorbs carbonic 

 acid, ammonia, and other nutritious gases, which 

 are received from the soil by the fibrous rootlets, 

 for the use of plants. Charcoal and other carbo- 

 naceous matters, absorb these gases with great 

 avidity. Hence the great value of carbonaceous 

 manures, as rotted straw, charcoal, &c. But a due 

 proportion of moisture is essential to absorption in 

 all cases. Hence the importance of an attention 

 to soils in reference to the absorption and retention 

 of water. Hence too the importance of frequent- 

 ly stirring and disturbing the dry surface of the 

 soil, in time of drought, by hoeing, ploughing, 

 &c. , in order to present a moist surface to the at- 

 mosphere ; without which, nutritious gases can- 

 not be absorbed. 



Carbonate of lime, sulphate of lime, and all the 

 soluble salts, as well as putrifying vegetables and 

 animals, should be considered as manures. They 

 all act either as absorbents like charcoal ; stimu- 

 lants, like gypsum, muriate of lime, &c. ; or as 

 furnishing nutritious matter by their decomposi- 

 tion, like fish, rotted straw, &c. Therefore the 

 geological agriculturist studies chiefly the propor- 

 tions of s/ones, pe66/es, c/ai/ and sand. The study 

 of that part of geology which relates to detritus, 

 is the true study of the first principles of elementa- 

 ry agriculture. 



By a reference to the system of classification, 'm 



the preceding part of this text book, it will be seen 

 that all detritus is distributed into eight deposites. 

 1. Plastic clay. 2. Marley clay. 3. Marine sand. 4. 

 Shell-marl. 5. Diluvion. 6. Ultimate diluvion, 

 7. Post diluvion. 8. Analluvion. After study- 

 ing the character of these deposites, nothing more 

 is required than a mere application of common 

 sense to each particular case. 



CLASSIFICATION OF SOILS. 



1. Plastic clay. This stratum is rarely found at 

 the surface of the earth, except at its out-croppitigg 

 in banks. It is destitute of any material portion 

 of carbonate of lime — being the clay used by pot- 

 ter-bakers. Without any intermixtures, it would 

 bake in the dry season, and be running mortar in 

 rainy weather. Intermixed with marine sand, it 

 would be tolerably productive. Wheat winter- 

 kills in it more than in any other soil. 



2 Marly clay. (London clay.) This stratum 

 is almost universal in bottom grounds. Alone, it 

 bakes, in a drought, and is mortar in a wet season. 

 Wheat winter-kills in it. But it generally con- 

 tains from fifteen to twenty per cent, of carbonate 

 of lime, and considerable muriate of lime. Wells 

 dug in it, almost invariably furnish " hard wa- 

 ters," o!i account of the muriate of lime. These 

 salts give it richness. Therefore if it is duly 

 mixed with marine sand (which generally over- 

 lays it) it forms rich and very durable soil. From 

 near Lake Champlain to Greene county, on the 

 west side of the Hudson, this clay, overlayed with 

 marine sand, prevails. Also throughout most of 

 the northern part of New-Jersey, along 'le val- 

 ley of the Mississippi, &c. If the vast plw-ns of 

 marine sand, between the Mississippi and Rocky 

 Mountains, are generally underlay ed with this 

 clay, as they certainly are in some localities, next 

 century may, under the hand of culture enliven 

 that barren waste with fruitful fields. 



3. Marine sand. (Bagshot sand.) This stra- 

 tum alone is a meagre barren soil ; but makes an 

 excellent kind when duly intermixed with the 

 marly clay beneath it, as mentioned under marly 

 clay. This stratum often passes into crag, or 

 stratified gravel, hardpan, &c. The crag is a bet- 

 ter soil alone, than the sand, excepting the hard- 

 pan, and some other varieties, wherein the gravel 

 is held together compactly by ferruginous, calca- 

 reous or clayey cement. But if duly intermixed 

 with the marly clay, it forms a good soil. 



4. Shdl-viarl. This deposite is a most excellent 

 manure, when intermixed with any of the other 

 soils — best in soils where clay predominates. It 

 is chiefly carbonate of lime ; but being made up 

 of broken shells or minute species, it is always in 

 a state suited to its application as a manure. But 

 when alone, it is not very productive, especially in 

 a dry season. 



5. Diluvion. As this deposite is the most he- 

 terogeneous of all deposites, it presents the charac- 

 ters of most other soils. In general it is very rich 

 in vegetable manure; but it is often too loose, and 

 requires an artificial intermixture of clay. It 

 presents all its characters along the Erie canal, 

 between the Little Falls and Genesee river. It fre- 

 quently affords localities of vegetable mould, which 

 may be advantageously carted upon other soils. 

 As it is generally in narrow slips or small fields, 

 the surrounding grounds may receive its benefits 

 with but little cartinff. 



