352 



THE FARMERS' REGISTER. 



lower parts of ihe country, being brought down 

 by floods and other causes. We must look, then, 

 to the composition of the rocks themselves. Sup- 

 pose of each of these which I will enumerate, a 

 field of 40,000 square leet (a Hessian acre) of 

 surface, with a depth of twenty inches, were de- 

 composed, the quantiiy of potash we might ex- 

 pect to find would be : — In felspar, l,152,000ib. ; 

 in clinkstone, 200,0001b. to 400,0001b. ; in basalt, 

 47,5001b. to 75,0001b. ; in clay slate. 100,0001b. to 

 200,0001b.; and in loam, from 87,0001b. to 300,- 

 0001b. We also find, that the aluminous or clay 

 earths, contain a large proportion of potash ; for 

 we can obtain it noi only lion) pure felspar, but 

 from the granites. The potash these contain is 

 not washed away by every shower of rain ; for 

 clay is a very impervious sort of material ; and 

 therefore, though the surface may be washed 

 away, the interior still contains a large proportion. 

 Wherever water penetrates, there the soil gives 

 ofi' its potash to the water, and this will be taken 

 up by the spongiules of the roots of plants. A 

 single cubic foot of felspar, if decomposed in 

 clay, is sufficient to supply wood of 40.000 

 square feet, with the quantiiy of potash necessary 

 lor the growth of limber upon it, for five years. 

 Do we not, then, see the use of many of the 

 composts now introduced upon the land.? The 

 very dirt collected upon our roads must contain 

 quantities of potash. The gritty portions of this 

 dirt undergo decomposition ; it is reduced to the 

 finest powder, and, from exposure to air and mois- 

 ture, undergoes disintegration ; and by this means 

 an abundant supply of potash may be obtained. 

 How does the earth, afier being exhausted by the 

 growth of plants, recover itself by lying fallow 1 

 It has the double advantage of not only having 

 its humus exposed to the air, and converted into 

 a sort of sponge ; but the inorganic materials are 

 still further decomposed by the action of the air, 

 and thus become ready to furnish to the next crop 

 the quantity of alkali required. We see that 

 where silica is required as an ingredient in the 

 portions of a plant, it is necessary that potash 

 should exist with it, to render it in some degree 

 soluble. Tlius the hard part of the bamboo, and 

 the stalk of vviieat, which contains silica, have it 

 accompained with potash, which assists the silica 

 to enter into a state capable of being assimilated 

 to the plant. There is another beautiful provi- 

 sion in plants, for taking up some of the more 

 insoluble elements, viz., that in one class of plants, 

 the graminecE, an acid is given out as an excretion 

 from the roots, producting an acetic fluid, which, 

 entering into combination with alkaline earth, 

 forms soluble elements, and allows them to be 

 taken up by ihe spongiules, and reduces them to a 

 state of assimilation. Planis growing there will 

 assist in the disintegration of rocks more than 

 mere weather will do. But suppose a soil pretty 

 rich in potash, and that the farmer is misled by 

 tlie desire of making the most of his land in a 

 short time. He grows upon that land plants, 

 which, when they attain their proper growth, are 

 removed from the land, burned, and sold for potash 

 — an article greatly in demand. The plant ge- 

 nerally selected lor this purpose is the artcniisia, 

 or wormwood ; if he grows it and sells tlie ashes, 

 and the next year thinks he will have a crop of 

 wheat, he will be disappointed ; for he has taken 

 from the soil that very material which is essential 



to the welfare of his wheat the following year. 

 Again, it is essential to the farmer to know which 

 of his crops take out the most of this principle, 

 as contained in potash, lime, or magnesia. To- 

 bacco and wheat require pretty much the same 

 proportion of potash at one period of their growth. 

 If the farmer attempts to cultivate the one after 

 the other, the result will be pretiy much the same 

 as if he tried to grow two crops of the same plant, 

 in two succeeding years. It would seem from 

 this, if the view taken by Liebig be correct, that 

 it is important the farmer should always know 

 what are the inorganic elements contained in the 

 crops he wishes lo have; for these must either be 

 found in, or supplied to the soil ; they cannot exist 

 in the atmosphere. He ought next to examine 

 his soil, and see if if contains them. If not, they 

 must be added. Upon this, it seems to me, the 

 important principles of agriculture depend. It is 

 not necessary that each farmer should be himself 

 an analyst ; but a number of fiirmers might unite 

 to procure the services of one ; and it is certain 

 that success would follow ihe application of these 

 principles. The quantity of inorganic elements 

 required by ihe [)lant in 100 parts of the stalk of 

 wheat, are 15.5 of ashes. In the same quantiiy 

 of the dry stalks of barley, 8,54; in 100 parts of 

 the stalk of oats, 4,42 ; and thus we see, that the 

 same field that yields only one harvest of wheat, 

 might be made to produce two crops of barley, or 

 three of oats, year afier year. The illustration of 

 the practice at Heidelberg, of allowing the wood- 

 cutters to burn the timber on the ground, will also 

 show how land, which has been covered by forests 

 for years, will, when the forest is consumed, become 

 abu»dantly fertile. It is owing to this, that the 

 trees themselves require but little alkali in propor- 

 tion to the grasses ; they hare been assimilating 

 this lor j'ears, and, when they are destroyed by 

 decay or combustion, that ground is abundantly 

 supplied with inorganic products necessary for a 

 crop, and also with a fair proportion of vegetable 

 soil. The common practice with farmers in the 

 rotation of crops is to follow grass with legumi- 

 nosce, which class ofplants contains no free alkali, 

 and only 1 per cent, of the phosphates of lime 

 and magnesia ; buck-wheat contains only .09 per 

 cent. These belong to the fallow crops; and the 

 cause they do not exercise any injurious influence 

 on the land cultivated is, that they do not extract 

 the alkalies from the soil, and only a very small 

 proportion of the phosphates. Now, is there not 

 something in all Uiis deserving the attention of 

 agriculturists 1 They have hiiherto gone on blind- 

 ly ; they have arrived at a certain state of know- 

 ledge from experience, and it so far a useful 

 guide ; but are they possessed of sufficient know- 

 ledge of facts connected with this importantsub- 

 ject to Ibrm a principle and rule, in reference to 

 crops and soils of various kinds, and the order of 

 succession ? And when we find a work publisli- 

 ed by a celebrated organic chemist, Dr. Liebig, 

 in which these principles are developed lor the first 

 time in Europe, are they not, I ask, highly deserv- 

 ing the attention of agriculturists'? They not only 

 apply to all the articles of our daily food, but to 

 the articles of raw produce which we consume in 

 our manufactures ; and, in fact, it seems that cul- 

 ture is not only useful, as supplying our animal 

 wants, but also to lay the foundation of the pros- 

 perity of stales, particularly of those engaged in 



