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While the population was comparatively small, the amount of land under cultivation was also limited, only the better class of soils in the most fertile districts being chosen for corn, and the remainder used for pasturage or common-land; whilst large tracts of country, capable of producing abundant crops, were left wild, or still covered with woods but as people congregated in centres of trade, the demand for corn arose and increased. Although, however, the farmer was thus encouraged to attempt the tillage of waste lands hitherto neglected, little improvement is noticeable in the method of farming until the beginning of the present century; for agriculture, like all venerable arts, has been—until very lately—strictly conservative; so much so, indeed, that many of its practices and precepts have come down to us but little altered since the days when Virgil wrote the Georgics.

But this century, so pregnant with change to all our industries, has not permitted agriculture to escape innovation; and notable among the signs of the time was the establishment, in 1838, of the Royal Agricultural Society, under whose auspices much has been done towards the removal of long-cherished and old-established prejudices, and the acceptance and adoption of numberless improvements.

The chemist has been, and indeed is still, hard at work for the agriculturist, analysing the soils on his farm, and advising him what artificial remedies to apply to improve their fertility, or to fit them for special crops. He has told him the reason why a rotation of crops is beneficial; because a green-crop, a root-crop, and a grain-crop each take different ingredients from the soil; and thus, by a knowledge of their requirements, he may apply to each that special ingredient—if not already in the land—at the period when it is required by the plant. Nor has Geology neglected to tender her aid to agriculture, by pointing out that there exists a direct relation between the soil of a given area and the subsoil upon which it rests: and that thus, by a knowledge of the geological features of a country, the farmer, in the selection of land, may not only be guided to the most permanently productive soil, but also to that which rests upon a subsoil calculated to enhance rather than depreciate its value.

Anyone who will take the trouble to examine a geologically coloured map of the British Isles, will see at a glance the general distribution, at (or near) the surface, of all the various geological formations, from the Pliocene and Eocene in the east and south-east, to the Granites and Trap-rocks of the west and north, with the relative superficial extent of each. But let us take a nearer view. In Britain, as in almost every country in the world, and in all latitudes, superficial accumulations of clay, sand, and gravel occur, sometimes forming a mere coating of the rocks beneath, but often of very considerable thickness, and covering large areas. The earlier geologists classed the whole of these deposits under the general name of Diluvium, and attributed their irregular occurrence and wide distribution to the effects of one great and universal deluge. They have, however, of late years, received careful attention from many able geologists, and it is now ascertained that theysometimes contain fossils.

Thus, some are named "pre-glacial," as marking by their animal and vegetable remains a coldly-temperate climate, and comprise marine sands and gravels, the lignite clays, and the forest-bed, with its elephant-remains, which are seen cropping out on the Norfolk coast. Younger than these, and overlying them—in Norfolk at least—come the accumulations of the "glacial" period itself, marked by the Arctic character of its fauna, its ice-worn erratic blocks, and its vast deposits of boulder-clay, often 100 feet in thickness, and covering large areas in the eastern, central, and northern counties of England. It presents most anomalous appearances, the fine clay or "till" being unstratified and mostly devoid of fossils, but containing rounded and angular fragments of rock, having one or more of their sides ground down and striated. The laminated beds which accompany the "till" in Norfolk are highly contorted, and much false-bedding and irregularity exists in their mode of deposit. To these succeed the "post-glacial" period, marked by a more temperate climate, and represented by deposits which have been formed since the land assumed its present level, or nearly so; including lacustrine and river-sediments, turf-moors, ancient forests—sometimes converted into peat-bogs, and now again reclaimed by man; valley-sediments, resulting from meteoric causes, and, in fact, all the most modern surface-deposits, including remains of man and his works.

Although what we have already said about the direct connexion between the soil and the sub-soil does relate to the regularly stratified deposits, such as the Chalk, the Oolite, Lias, New Red sandstone, &c., yet it is found by careful observation that those modern and superficial patches of clays, sands, and gravels scattered over the face of the country far and wide, take such an important part in modifying the general character of the soil, that to the agriculturists of some districts, they actually surpass in interest and importance the more regular geological formations of the country.

When the Geological Survey of Great Britain was first undertaken, more than thirty years ago, the Director-General had to consider and decide which would be the most desirable plan to pursue,—whether to show on the geologically-coloured maps these "detrital" or "superficial" deposits, lying upon and concealing the more regularly stratified formations, or only to map the latter; and bearing in mind the fact already stated, that only the most vague notions existed in the minds of the earlier geologists as to the age or origin of these later deposits, and that they were commonly looked upon as the result of the deluge; it is easy to see that there were at that time good grounds for their omission. It can, however, readily be shown that, from an economic point of view, these deposits deserve to be mapped, in the interest of the farmer, with as much accuracy as the older rocks have been for the miner.

The advantages to be derived by the farmer from the mapping of all surface-deposits—irrespective of age or mode of occurrence—are exemplified in the pages of the last number of the Journal of the Royal Agricultural Society, in which the system commenced many years ago by the Council of that Society, and carried out so ably on their behalf by Mr. Joshua Trimmer, of making reports upon the agricultural geology of lands in various districts of England, has been again resumed. In this instance, most of the reports are the result of personal