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to be 8,000,000 of quarters, it will require, at 24 quarters an acre, 3,000,000 of acres to produce that quantity: the seeding this extent of land, will consume about 1,000,000 quarters of seed corn. This quantity, added to the public stock in a year of dearth, cannot fail to produce some effect in lowering the prices: if it is to be purchased from foreign nations, it will, at the rate of 41. a quarter, cost 4,000,000l. sterling, and, at the weight of 56lbs. a bushel only, employ 200,000 tons of shipping to bring it home.
The deficiency of the crop of 1804 was very great; the mildew was the principal cause of it; in some places the smut also prevailed, but in no considerable degree: the lowest land in all cases fared the worst, except when exposed to the immediate influence of the sea winds; the higher lands were less damaged, and in some places wholly escaped. The counties north of the Teese were much less affected than the south, and Scotland escaped wholly.
On the Duke of Bedford's farm at Wooburn, the wheats were severely hurt, though by no means so entirely destroyed, as in the rich low countries.
By experiments tried under his Grace's orders, the following comparison was made between the crops of wheat of 1804, and those of the two preceding years:
Number of Sheaves to
a Load of 5 Bushels.
Produce of a Load in
which makes the deficiency of the year 1804, when compared with the crop of 1802, about 30 per cent. in the measure of the corn, and 26 per cent. in the weight of the flour. These added together give a total deficiency on of 1804, of 56 per cent,
It is not unlikely, from the situation of the Wooburn district, that its deficiency offers a reasonable average of the deficiency of the island, south of the Teese; considerable allowance must nevertheless be made in estimating the whole deficiency of the crop, as the counties north of Teese, the whole of Scotland, and the lands open to the sea, escaped; it cannot, however, be doubted, that if we estimate the deficiency of wheat on an average of the whole island, at one third of a medium harvest, we rather underrate than exceed. If then we admit the annual consump tion of the island to be 8,000,000 of quarters, this deficiency will amount to 2,666,000 quarters. Yet, notwithstanding this immense deficiency, the prices, though high, never became exorbitant.
The importation between the 10th of October, 1804, and the same period of the year 1805, was 893,271 quarters of wheat, and 67,308 cwt. of wheat flour, in all not amounting to 1,000,000 of quarters; the remaining deficiency must have been made up by the stock in hand, which was considerable, and by the use of substitutes, which having been so severely inculcated by the late recurrences of dearth, was cheerfully, and almost universally, resorted to -potatoes fortunately were abundant and cheap.
Notwithstanding all this, it is difficult, on any usual mode of calculation, to judge why the prices were not raised higher; but it is remarkable, as has been hinted in pages 406 and 407, that years of blight never raise corn to so exorbitant a price, as is always demanded in case of a wet harvest.!
The average price of wheat for the whole year, 1805, is estimated by my ingenious friend, Mr. A. Young, at 10s. 10d. a bushel. That of 1800, was 14s. 1d. and that of 1801, 14s. 8d.; being the highest average price of which we have any account.
MY DEAR SIR,
IN consequence of the information I derived from letters I had the honor to receive from you, and from your little pamphlet on the Blight of Wheat, I made a few experiments in the course of the last summer, the result of which I take the liberty to send you My observations, are, however, of little value, and tend only to point out one amongst the many predisposing causes to which diseases of that kind probably owe their existence.
An opinion prevailing very generally in this, as in other districts, that the barberry tree communicates disease to wheat and other plants in its vicinity, I sowed, in the autumn of 1804, a row of wheat round a plant of that kind, which grew in my garden, the soil of which is a shallow loam or a limestone gravel; and I also sowed several small portions of seed of the same kind in a meadow, the soil of which was very similar to that of my garden, though situated at a considerable distance from it. All the plants continued perfectly healthy till the beginning of July, when those near the barberry bush showed evident symptoms of disease. Small elevated points, of paler color than other parts of the plants, first appeared on the leaves and straws, occasioned by the epidermis having been raised by the growth of minute fungi
under it. The increase of the disease was from this period extremely rapid, and in the course of a single week the straws were covered with yellow spots, exactly as they are delineated by Mr. Bauer.
Examining the barberry bush attentively, Ifound upon its fruit a species of fungus similar in color to that on the straws of the wheat, but its seed vessels were larger, and more spherical. I was, however, much disposed to believe the parasitical plants of the same species, and that the difference in the form and size of the seed vessels arose only from the difference of the nutriment they derived from the wheat, and from the acrid juice of the barberry.
The plants of wheat, which grew at a distance from the barberry bush, remaining free from disease, I carried a branch of the barberry, with diseased fruit upon it, to one of them, and wetting it with water, I brushed the wheat plants with it, repeating this operation three successive days. I at the same time applied a part of the diseased straws which had grown near the barberry bush, to other plants of wheat, which were free from disease, leaving upon them so large a portion of the seeds and seed vessels of the mildew, as to be visible without the aid of a lens. In the course of ten days the plants of wheat, which I had endeavoured to infect by means of the barberry branches and fruit, became covered with disease, whilst those to which I had applied the mildewed straws were not sensibly affected. I attributed the health of these to the want of moisture necessary to make the seeds of the mildew vegetate, and I therefore sprinkled them plentifully with water in the three succeeding days; and at the end of ten days I found them all diseased as in the preceding cases.
As water had been applied in each of the preceding experiments, it became necessary to ascertain how far that fluid alone might be capable of inducing disease without the aid either of the barberry, or diseased straws; and I therefore, whilst repeating the experiment last described, sprinkled a remaining portion of plants at the same hour with water only; and I was not very much surprised to find, that these became as much diseased, within the same period oftime, as any of those I have described.
In each of the preceding experiments, very cold water was ap
plied early in the afternoon of a warm and bright day; and the ground in which the plants grew was also very dry. A consi derable absorption, therefore, probably took place; and to this ab sorption, and the effects of a sudden change of temperature, as secondary causes, I am disposed to attribute the appearance of the disease; but whether the seeds of the mildew were carried into the pores of the plants by the water, or existed there before, is a question which I shall not attempt to solve. The application of cold water to any plant on which the sun is shining strongly is very injurious to its health, and therefore likely to give increased activity to any disease, to which the plant is subject.
In the last experiment there is not the slightest reason to believe that the disease was communicated by the barberry; and it may be doubted whether that plant contributed to produce the disease in any of the preceding cases; and indeed in any other instance: nevertheless, the opinion so generally entertained, both in this kingdom and on the continent, by practical farmers, that barberry trees are injurious to corn, deserves very considerable attention; and though the parasitical plant found on the barberry may be dissimilar in some respects to that found on wheat, it must not be immediately decided that they are specifically different. The primrose, the cowslip, the oxlip, and the polyanthus, Linnæus states to be the same plant; and experiments I have made, leave no grounds of doubt that they are the same; yet had these plants been nearly as minute as the fungi on the straws of wheat, they would for ever have been considered as distinct species.
Experiments, which I have annually been in the habit of making on pease, leave no grounds of doubt in my mind, that want of moisture at the root, with excess of it on the leaves and stems, is one at least amongst the secondary causes of mildew in that plant. Every gardener knows, that, in autumn, when the ground is dry, and the dews cold and heavy, the pease always become mildewed; and that the crop is in consequence rendered of small value at that season. But I have constantly succeeded in preserving the health of my autumnal crops of pease, in rendering them nearly as abundant in the end of September and beginning of October as in July; and as the method I have adopted may throw some light on the cause of the