cus arvensis, that the land is not well farmed. Whenever there is the least admixture of peat in the soil, the Erica or Calluna and spotted-bearded orchis, Orchis maculata, are sure to be there. (555.) Taking a more extended view of the indications of the condition of soils, these observations of Dr Singer seem well founded. "Green mountains, like those of Cheviot and Ettrick Forest, abounding in grass without heath, indicate a strong soil, which is rendered productive, though frequently steep and elevated, by a retentive subsoil. This quality, and the frequent mists and showers that visit rather elevated sheep-walks, render them productive in strong grasses (Agrostis).. Dark mountains, clothed with a mixture of heath and grass, indicate a drier soil on a less retentive bottom. Such are many of the Highland mountains, and such also are some of those which appear occasionally among the green mountains of the southern pastoral district, in which the light soil is incumbent commonly on gravel or porous rock. On these dark-coloured mountains, a green and grassy part often appears where there is no heath, and the subsoil is retentive; and if the upper edge of such a spot appears well defined, this is occasioned by the regular approach of a stratum of clay or other substance impervious to water towards the surface, and the green hue disappears below, when the subsoil again becomes open. On any of the mountains, whether dark or green, when the fern or bracken, Pteris aquilina, appears in quantities, it indicates a deep soil and a dry subsoil."* A stunted growth of heath indicates a part having been bared by the paring-spade; and when vegetation becomes of a brown colour in summer, the subjacent rock is only a little way under the surface. (556.) Viewing the connection of plants to the soil on the great scale, we cannot but be forcibly impressed with the conviction that "the grand principle of vegetation is simple in its design; but view it in detail, and its complication astonishes and bewilders." And yet, as Professor Macgillivray justly observes, “it is the same sun that calls forth, and thus elicited, gives vigour to the vegetation, the same earth that supports it, the same moisture that swells its vessels, the same air that furnishes the medium in which it lives; but amid all these systems of general, how multiple the variations of particular constituent causes, and how infinitely diversified their results!”† (557.) Before leaving the subject of soils at this time, it appears incumbent on me to make a few observations on their classification. The use of a classification would be to enable every writer who has occasion to allude to soils to indicate the particular kind which he wishes to describe so precisely, as that any one else should identify it. You are, no doubt, aware that all the plants which I have had occasion to mention may be identified in any part of the globe, so precise is their description; but the case is very different in regard to the soils I have mentioned as having a connection with those plants, not one of which, with perhaps the exception of pure sand and pure peat, could be identified by any remarks that have been made in reference to their qualities. I suspect that so much precision is not to be attained on the subject; but, nevertheless, it appears to be the general opinion that an attempt towards it should be made, and every writer on agriculture has made the attempt, in the way he has thought best. * Prize Essays of the Highland and Agricultural Society, vol. vii. p. 464. Although they have all failed in establishing such characteristics of soils as might render them easily recognized by description, yet it is worthy of remark, that they have found it necessary to adopt the same principle in their respective classifications which is practised by every farmer in raising his different crops, namely, of suiting them to the different kinds of soils. In adopting this principle, it is obvious that neither the external characters of the mineralogical system, nor their chemical composition, have been employed to describe the properties of soil, but simply their natural powers to grow the plants desired to be raised in cultivation. Still a simple description of the materials which evince those natural powers is yet a desideratum. (558.) I observe that the Government have offered to the Royal Agricultural Society of England to make a complete and systematic analysis of all the soils of England at the public cost. The various soils to be selected from the same geological formation in different parts of the country, and particularly those which have been found by experience to be best adapted for particular crops (as wheat soils, bean soils, turnip soils, grass soils, fertile soils, barren soils, &c.), to be taken in succession from one end of the kingdom to the other. Το do this in the most satisfactory manner, it is proposed to obtain 20 analyses of each particular soil, and thus procure, in the course of every year, about 1000 of such analyses, which are to be made by chemists of first-rate character for analytical investigations of the kind, and who should ascertain not only the chemical constitution, but the mechanical texture and properties of each soil, and the results to be published, as occasions demand, in the journal of the Society.* It is not improbable that these minute analyses may enable chemists or mineralogists to institute a nomenclature of soils in conformity to their true external characters, that is, to their most apparent and easily-tested properties. (559.) Meanwhile, I shall present you with a sketch of an attempt at classification of soils by M. De Gasparin, who, although he employed chemical tests to ascertain the nature of the soil, had previously endeavoured to establish their agricultural characters. The results were, that he was led to adopt the following conclusions in regard to the relative values of the characters of soils. It is," he says, "only after having destined a particular soil to an appropriate culture, that we can begin to consider the labour and improvement it requires. Those labours and improvements will be without an object and a bearing, if we are still ignorant of the plant to which they would be useful. And, moreover, this investigation of the appropriation of soils to particular kinds of culture, is connected with the most natural classification in a mineralogical point of view; it breaks the smallest number of affinities, and consequently renders the determination of soils more easy and more satisfactory." I cannot help thinking that M. De Gasparin has here hit upon the principle upon which a true and useful classification of soils may be founded. (560.) In his endeavour to reduce this principle to practice, he has divided soils into two great divisions; the first includes those having a mineral basis, the second those having an organic one. Pell's Weekly Messenger, and Mark Lane Express, 7th March 1842. † Comptes Rendus de l'Académie des Sciences, tome viii., No. 8, p. 285, 1839, and translated in Jameson's Edinburgh New Philosophical Journal, vol. xxvii. p. 84. I may here mention that M. de Gasparin is engaged in a work on Agronomy. Z (561.) The first great division, consisting of soils having a mineral basis, he divides into 4 classes, comprehending saliferous soils, siliceous soils, clays, and calcareous and magnesian soils. (562.) The character of saliferous soils is, that they have "a salt or styptic taste, containing at least 0.005 parts of hydrochlorate of soda, or sulphate of iron;" and they consist, 1st, of saline soils, and, 2d, of vitriolic soils. (563.) The character of siliceous soils is, that they produce "no effervescence with acids, affording by levigation at least 0.70 of large particles, which are deposited when the water in which the earth is dissolved is strongly shaken." (564.) Clays are characterized by "not yielding effervescence with acids, and by affording by levigation less than 0.70 of the first portion." (565.) And the characters of calcareous and magnesian soils are, that they produce effervescence with acids; lime or magnesia, or both, being found in the solution." This class is subdivided into 5 sub-orders, namely, chalks, sands, clays, marls, and loams. The marls, again, are farther subdivided into 2 sections, namely, calcareous marls and argillaceous marls. (566.) The second great division, consisting of soils having an organic basis, he divides into 2 classes, comprehending fresh mould and acid mould. (567.) The character of fresh mould is, that "the water in which this mould is digested or boiled does not redden litmus paper." (568.) That of acid mould being, that, under the same circumstances, it "reddens litmus paper." (569.) It is intimated that M. De Gasparin has laid down rules for the description of species, and with examples of all the methods of description. In reading these, we at once perceive how precise an idea of soils is conveyed in a manner that cannot be misunderstood by any agriculturist. The possibility of transmitting these clear and pointed descriptions to a distance, follows as a matter of course; and we shall in this manner be freed from all that vagueness which has been so long a just cause of complaint." This is all that is desiderated on the subject; but, useful as M. De Gasparin's services to agriculture have been in the right direction, he has not yet succeeded in establishing a faultless description of soils, for let me apply some of the rules he has given above, and test his own description by them. For example, he says, that clay soils are characterized by "not yielding effervescence with acids, and affording by levigation less than 0.70 of the first portion ;" and the character of siliceous soils he gives in these words, "producing no effervescence with acids, affording by levigation at least 0.70 for their first portion." Surely the mere difference of affording "at least" and "less" than 0.70, or any other minute proportion of any ingredient, is not sufficient to account for the great difference there is found to exist in agriculture betwixt clay and sandy soils. He does not, however, confound loams with days, as some theoretical writers whom I have quoted have done, the loams containing clay only a little "more than 0.10 of the weight of the soil;" whereas clays afford only a little "less than 0.70 of the first portion" of the matter separated by levigation, thereby establishing a very great difference of character betwixt them. (570.) Little reliance, I fear, can be placed on any analyses of soils hitherto attempted, to guide us to a correct nomenclature and classification. phry Davy, for instance, gives an example of the absorbent powers Sir Hum"of a ce lebrated soil from Ormiston, in East-Lothian,"* a given quantity of which, at a given temperature, absorbed 18 grains of moisture; whereas " a very fertile soil from the banks of the river Parret, in Somersetshire," of similar quantity and under similar circumstances, absorbed only 16 grains; thereby leaving it to be inferred, that the Ormiston soil was better than the other, which it may possibly be, but it is well known by those who know it practically, that it is far from being a fertile one. There exist, besides, many serious discrepancies betwixt authors who write on the composition of soils. M. Von Thäer gives three instances of "rich wheat-land," which contain from 74 to 81 per cent. of clay, and from 6 to 10 per cent. of sand :† while Professor Johnston, after stating that the pure porcelain clays are the richest in alumina," adds, that even when free from water, they contain only from 42 to 48 per cent. of this earth, with from 52 to 58 of silica." Mr Loudon gives a tabular view of a classification of soils, said to have been adopted by M. Fellenberg in Switzerland, and Professor Thouin of Paris, but to remember the particular nomenclature of which would puzzle any tyro in agriculture. § 66 (571.) There is no doubt, however, of the truth of the opinion expressed by M. De Gasparin, were a correct nomenclature and classification of soils established, when he says that its consequence would be, "that the study of agricultural treatises would be greatly facilitated; the different methods (of culture) which are followed in distant countries will no longer appear so marvellous, and will become more intelligible; we shall comprehend better the considerations which limit or extend the several cultures; and a necessary link being established between the science of agriculture and the other natural sciences, it will become more intelligible to all, and will more readily profit by the progress of all the other branches of human knowledge." 23. OF ENCLOSURES AND SHELTER. "Some husbandmen deem fences only formed GRAHAM. (572.) Although it may happen that the farm on which you are learning your profession, or the one which you are to occupy on your own account, may be completely enclosed, yet as the reasons for enclosing land are both numerous and cogent, it is proper that you should not only be made acquainted with them, but be able to appreciate the sound principles upon which they are founded. * Davy's Agricultural Chemistry, 8vo edition, p. 176. ↑ Von Thäer's Atlas des Principes Raisonnés d'Agriculture, Tableau No. 26, p. 74, § Loudon's Encyclopædia of Agriculture, p. 312. (573.) The advantages derived from enclosing land are these: 1. Enclosures shelter every kind of crop, as well as live stock, from the inclemency of the weather, and particularly against a cold and powerful wind. 2. They prevent the trespasses of men across, and animals into, fields. 3. They not only afford the most excellent and efficient shelter to live stock, but secure peace and protection to them while feeding and when at rest in the fields. 4. They enhance the value of land in every situation: an enclosed farm, in all other circumstances alike, will fetch a higher rent than an unenclosed one. From 2s. to 5s. per acre, according to the locality and nature of the ground, is not too high an estimate of their advantage on this head. 5. They greatly beautify the aspect of the country, conferring on it an undeniable sense of security, richness, and comfort. 6. They also confer ease of mind to the farmer, by securing his crops, his flocks, and his herds, from ordinary danger. 7. They impart confidence to the country gentleman in the enjoyment of his estate of land and wood, by being the means of continually improving it, so long as he maintains the fences in an efficacious manner. 8. And they improve the local climate to a sensible degree. Dr Skene Keith estimates the increase of temperature, occasioned by enclosures, to amount to from 5° to 8° Fahrenheit. (574.) The particulars which first claim attention in commencing the enclosing of a farm, are the nature of the soil and the locality of the farm; because these fix the system of husbandry to be adopted, and that again determines the number and size of the enclosures. (575.) On pure clay-soil farms, enclosures are not so necessary to protect corn from the trespasses of live stock, there being only the working stock on such farms in summer, as a protection from the weather. Though clay-soils are generally situated in flat plains, margined with rising grounds; yet enclosures placed there as screens against prevailing winds, will much improve the local climate. In practice, such farms are seldom enclosed at all, on the idea that the ground is too valuable to be occupied by any kind of fence; but this is obviously a short-sighted notion; for all unenclosed farms are subject to being trespassed upon by live stock passing along the roads, and by people walking across the fields to shorten their journeys to church or market. Hence the prevalence of footpaths across fields in England, which had been established before the general adoption of field-enclosures. Besides all that, windy weather in harvest, in some seasons, damages more corn in one day, than the exhaustion of the soil by a well trimmed hedge would for any length of time. (576.) Enclosures are absolutely required on all loamy soils, of which |