“ The reason is obvious: the more succulent a plant is, and the greater the quantity of moisture it has imbibed, the more susceptible must it be of injury from frost; the fuller its vessels are the more liable are they to be ruptured. Farmers, whose fears are always alive, anticipate a mildew from the continuance of a raw and foggy air in the spring or early part of the summer: nor are they often mistaken. In such a continued state of atmosphere, the grasses open their innumerable orifices, and imbibe a prodigious quantity of moisture ”

“ Whatever preserves corn in a healthy state, whether wheat, barley, oats, peas, or any thing else, arms it against the attack of those parasitic fungi which, when they have taken possession of the plant, we call the mildew, and which is rather to be considered as the consequence of previous unhealthiness than as a disease per se. Too great luxuriance and too little are alike injurious; a man may kill himself by eating too much as well as too little, and die of fat, instead of famine. The adaption of seed to soil and climate, by promoting the health may repel the mildew of the corn ”

“ But I fear that experiments on the vegetation of suspected seeds have been too commonly made in some snug sheltered corner of a fertile garden; or we put a little rich mould into a pot, and bring it into the house: the seeds sprout, are carefully watered, and nursed up, and a hasty, dangerous inference is deduced, that refuse corn may as safely be employed for seed as the plumpest and the soundest kernels: thus are chickens cheated of their victuals, and the crops of the whole country exposed to imminent danger through a mistaken and pitiful economy. ”

“ How comes it to pass that the mildew, blight, call it what you will, should be so partially distributed that of two adjoining fields, nay that of two adjoining ridges in the same field, one may be entirely exempt from the disease, and the other severely suffer by it? But every farmer knows that this is no imaginary or even uncommon case: the track of the mildew is oftentimes remarkably distinct, which it would hardly be if the air were impregnated with this poisonous and prolific dust. ”

“ The fact, however, is as Sir Joseph states it, namely that the leaf is first infected in the spring, or early in the summer. No one fears what is called a mildew on his wheat crop after the blossom is set. The season of flowering is indeed a very critical one: heavy rains and blustering winds may wash away or so disperse the pollen as to frustrate and render abortive the necessary process of fecundation. For the same reason it is injudicious to hoe corn during the time of blossoming; the clothes of those employed are very likely to brush away the farina and injure the impregnation. ”

“ I suspect, that on such soils, and at such a season, to retard vegetation by a starveling seed, would be a most perilous experiment, the young plant requiring all the nourishment which the plumpest kernel can supply, in order to preserve its existence and enable it to bear the rigor of the season during a protracted infancy.
The harvest of 1799 was the wettest that had been known for many years: farmers brewed beer from barley which the rains of heaven had malted. It was the general opinion that black, or even discolored barley, was very unsafe to be used for seed. ”

“ November may be considered as the commencement of our winter: the season now grows cold and rainy, and the wheat which at that time remains in a heavy, strong and undrained soil, or which just peeps through the surface, has many sad vicissitudes of weather to encounter in its first feeble state, and lies a long time exposed to the depredations of hungry birds. ”

“ On heavy lands the progress of infant vegetation is always languid: when a seed first germinates, it is obvious that the plumula and the radicle must be much longer in struggling through stiff clods of earth, than when they have only to insinuate their easy courses through a pulverized and unresisting soil; and at the time of year when our wheats are usually committed to the ground, the difference of a few days only in the time of sowing is on some soils succeeded by a difference of weeks in the first appearance of the crops. ”

“ Thus, on rich luxuriant soils where the crops are much disposed to have great length of straw, and consequently are very liable to be laid during the summer, it seems desirable to select seed from a poor and naked soil where it has been the habit of the parent plants to bear deficient straw: on the contrary, upon those bare and barren heaths, where a meagre vegetation does not half conceal the parched-up ground, it is probably adviseable to obtain seed from the most luxuriant and fertile fields. ”

“ Barley, also, grown on sandy soils in the warmest parts of England, is always found by the Scotch farmer, when introduced into his country, to ripen on his cold hills earlier than crops of the same kind do when he uses the seeds of plants which have passed through Several successive generations in the colder climate of Scotland.
Farmers have certainly an indistinct and confused notion of some benefit to be derived from changing their seed: and accordingly, every three or four years, most of them do obtain from some neighbour a supply of seed-corn. ”

“ The cotyledons or lobes of the seed appear to be merely organs of nutrition, communicating the farinaceous substance of which they are composed to the young plant: if this nutritious substance is liberally communicated, which we suppose to be the case when the cotyledons are large and plump, the plant surely must thrive better and grow more rapidly than when the cotyledons, shrunk and shrivelled, distribute a parsimonious and scanty mucilage. ”

“ Perhaps it is unwise to sow wheat on newly broken-up lands: they are so rich and so spongy that an unhealthy luxuriance is produced. They should not be trusted with wheat until they are sufficiently drained, and are become firm: the roots of the young plants in such situations are particularly preyed upon by the wire-worm and other insects. This injures their growth, and produces a sickliness which unfits them for resisting the attacks of fungi. ”

“ The heat from the surface of the earth then is much sooner reduced to the temperature of the incumbent air than the surface of the sea, the surface having but a slow and imperfect supply of heat from the interior, while the sea, from the change of specific gravity and other causes of motion, is constantly presenting a warmer surface to the air ”

“ Being the inhabitant of a tropical climate, and found on the most stony and arid situations, nature has furnished it with the means of an ample supply of moisture, without which it would have withered and perished. To the footstalk of each leaf, and near the base, is attached a small bag, shaped like a pitcher, of the same consistence and colour as the leaf in the early stage of its growth, but changing with age to a reddish purple ”

“ Now it is obvious that spring corn is free from the frosts of winter, and much more so from those of spring than the corn which is sown in autumn. Wheat is a very hardy plant, but it suffers probably more severely from the vernal than the winter frosts. If the season is mild the vessels of the young wheat begin to fill with fluids as early as the latter end of February or beginning of March ”

“ If heat be generated on land in proportion to the continued absorption and fixation of the rays of light, its accumulation on the surface will be retarded by the power which the soil has of transmitting it downwards, a power which may vary according to the nature of the substances of which the soil is composed, and to its comparative dryness. ”

“ The fact is, that plants, like animals, are morbidly affected by any violent transition either from heat to cold, or from cold to heat; by the too sudden abstraction or the too sudden accumulation of stimuli. Laurels and other shrubs, which have been carefully planted on the south side of a house for the sake of protection against the cold, are very likely to suffer in the winter for want of protection against the sun, while others which are exposed to the uniform severity of a northern aspect pass uninjured through the rigors of the season. ”

“ Perhaps a very early luxuriance of the grass of wheat is to be deprecated: where the soil is light and fertile, therefore, and where the situation is sheltered and warm, it may be better to sow wheat at Christmas than at Michaelmas. ”

“ As the summer advances, therefore, the air must be more and more heavily laden with these seeds, and as the size of the cuticular orifices of the straw increases with its growth, the seeds of the fungus would find more room as the summer advances, and the mischief extend with an immeasurable rapidity over the whole country. We should never be free from it: many thousand acres would annually be destroyed in the summer, which were uninfected in the spring. ”

“ The corn becomes shrivelled in proportion to the number and activity of these fungi, and as the kernel only is abstracted from the grain while the cortical part remains undiminished, the proportion of flour to bran in blighted corn is always reduced in the same degree as corn is made light. ”

“ After all, evaporation is the great generator of cold, and although there may be some intrinsic and original difference in the capacities of different earths for retaining heat, abstracted from the retention of water, Mr. Egremont cannot avoid concluding, it is to that retentive power that the chief cause of difference is assignable, and that soils are good and bad conductors of heat according to the moisture they contain. ”

“ It is much to be apprehended, that although shrivelled kernels may very well succeed as an experiment in a garden pot, or in a very rich soil and warm situation, they would miserably frustrate the expectation and punish the credulity of a farmer, if employed on an extensive scale, without peculiar advantages of soil, season, and situation, and without an extraordinary measure of manure. ”

“ In a district called Marshland, in the West Riding of Yorkshire, the culture of potatoes is carried to a very great extent; consequently great quantities are planted late in the summer, and depend on a favorable autumn for an abundant produce. Early frosts frequently disappoint the cultivator, sometimes by coming so soon as the beginning of September. After the frost, during the early part of the succeeding day the mischief is scarcely perceptible, and ultimately it is found to be in proportion to the temperature and brightness of that day. ”

“ As the Scotch farmer has found advantage by obtaining seed-corn from the warmest districts of England, so the farmers of the northern and the eastern counties of England would probably reap similar benefit by having recourse to their brethren of the west and south. ”

“ But generally I believe it will be found that land is heated or cooled sooner, and to a higher degree, than water: whence it will have a greater range of temperature, and the air incumbent on it, as well as other bodies in contact with it, will be hotter in summer and cooler in winter than that over the sea. ”

“ Where the ear is partially blind, or where without any external appearance of injury to the straw, the corn is light and shrivelled, I should be much inclined to suspect that the mischief arose from an insufficient impregnation. ”

“ The irritability of plants is unquestionably increased by the subduction of heat: vines in grape-houses, which have been exposed to the external air and all the cold of winter will become forwarder and more vigorous at spring than those which have been confined within the warm atmosphere of the house throughout the winter. Onions, potatoes, barley, &c. ”

“ These plants become unhealthy from superabundant moisture, rather than from excessive cold, or sudden variations in temperature, and in consequence of that unhealthiness are attacked by parasitic fungi which they are incapable of repelling. Where there is a substratum of clay through which no water can filter, the land is soaked and saturated with it, and can only be relieved by the tardy process of exhalation. ”

“ He says, that although the seeds of wheat are rendered so lean and shrivelled by the exhausting power of the fungus that scarcely any flour fit for the manufacture of bread can be obtained by grinding them, these very seeds will, except perhaps in the very worst cases, answer the purposes of seed corn as well as the fairest and plumpest sample that can be obtained. ”

“ Fungi find an appropriate nidus in diseased and decayed vegetable matter, and particularly if it remains in a state of moisture; the wood-work of vaults, as was before observed, and indeed their walls are always covered with them, rotten timber and the hollow trunks of trees are rarely free from them. Nature suffers no fit recipient for animal or vegetable life to remain void ”

“ Sir Joseph has taken upon himself a vast responsibility only to be justified by a long and careful series of experiments, personally conducted by himself.
It is one thing to bring children into the world, it is another to rear them. Adam Smith remarks of the Highland women, that they frequently bear more than twenty and have not two alive! ”

“ Nor will this principle be found less useful in accounting for the different effects which a sudden change in the heat of the atmosphere may produce on certain vegetables, in different or even on the same soils when under other modes of management. Whatever has a tendency to check a quick and great loss of temperature in the substances which surround such vegetables, particularly their roots, will be best calculated to save them from that effect and from vegetative death ”