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Transactions of the Highland and Agricultural Society of Scotland
Reports on the disease of the potato crop in Scotland for 1846

This is but a few of the many reports published in this report.


The Highland and Agricultural Society of Scotland, with the view of ascertaining the state of the potato crop last year, again issued a series of Queries similar to those circulated among the agriculturists of Scotland in 1845. The results of the investigation are now given in the form of Reports from various parts of the country, including districts which had escaped the disease in 1845. The Queries sent will be found in the previous Report, and it is needless to repeat them here. It does not appear necessary to enter into an analysis of the Reports, as the results in most instances correspond with those of 1845.

ABERDEENSHIRE.

No. 1. - Mr John Hutchison, Monyruy, near Peterhead, 19th Dec. 1846.

I have this season to give quite a different report from last year; as, instead of never having seen the disease in this quarter, I cannot now hear of a single instance within many miles, where the potatoes have escaped.

On the 3d of August, I first noticed the leaves of a few potatoes affected; nothing could then be seen on the tubers. I put two men to cut off the leaves of about one-third of the crop. On my return from Aberdeen that week, I found the tops of all the others gone, and a few of the potatoes affected. The disease spread very fast after that for at least a fortnight; when it seemed to stop. The tubers did not grow after the tops were smitten; and most of the diseased ones were close to the stem, or near the surface. There might be one-fourth to one-fifth of the tubers left usable ; these not mealy, but waxy. The purple cluster was most affected. No potatoes that I have heard of being raised and pitted, have kept a week - all have gone. Most people here have left their potatoes in the ground undug all winter, by which means it is expected they will have a few in spring. I have dug mine daily (until the late snow), without much difference on them for months. I have also planted from one and a half to two acres, which I have examined several times, and they appear to be keeping well; they were carefully picked.

The half-bad potatoes I made into fine potato starch. I had some of all my different sorts planted, without any dung, purposely for seed next year, on poor dry land dug out of grass; and these were all smitten the same as the others ; most of them not being earthed up, and being nearer the surface, were worse. I had, however, a number of recent seedlings among them, one of which in particular was nearly safe in the tubers, the stems having decayed, and it seems to have been more hardy than the others. My early garden potatoes were ripe, and dug before the disease appeared—quite sound and of fine quality; they were put on the surface of the ground to green, but decayed faster than any other; not one was saved.

It would appear to me the disease came from the atmosphere: the weather at the time was dry, very warm, frequent fogs, especially during the night, with a great deal of electricity in the air.

No. 2. - Mr Wm. Garden, Balfluig, January 1, 1847.

Tub potato disease was first observed in the Alford district about the 1st of August 1846. I am not aware of any instance of the disease in this part of the country in the crop of the previous year. The leaves of the potato were first affected with small brown spots, which afterwards extended to the stems, and last of all, the tubers nearest to the surface of the ground became diseased. As the disease progressed, the leaves and stems gradually sank down and withered. Some of the plants were in flower when the taint appeared, but most of the varieties had passed the flowering stage, and had plums more or less formed. When affected with the disease, the flowers became withered, and the stalks of the plums faded and sank down with the rest of the plant. The tubers, when affected, presented a rough appearance on their surface; and their substance under the cuticle had a brown gangrenous appearance, to a greater or less depth, according to the extent of the disease. In the black and purple varieties, it was difficult to distinguish the diseased from the sound, without removing the cuticle. The disease evidently extended from the leaves and stem downwards. The mean temperature of July was 59.12 deg.; and the mean daily range, 11.9 deg. of Fahr. The depth of rain which fell during that month was 5'7 inches. The weather about the time of the appearance of the disease was hazy and sultry. The mean temperature of May, June, July, and August, was 57.48 deg. The amount of rain during that period, 15'15 inches. In this district I had never observed such a mean high temperature accompanied with such an excess of moisture, during these months. No variety of potato cultivated here, has entirely escaped the disease; although sometimes one variety, sometimes another, has been more or less affected on different farms. With regard to one kind of potato, these observations do not apply, as, on six or eight different situations, in which it has been grown, it has been much less affected with the disease than any other variety. I do not know the name of this variety, but it is a small round potato, of a light pink colour, with deep eyes. [Probably the variety named cups.—Edit.] In all cases, though slightly tainted, it has produced three-fourths of sound tubers, and in many instances much more. From the loaves and stems having been affected, the tubers did not attain that size which they otherwise would have done. I had some of this variety grown on land which had been long under cultivation. Of these, fully three-fourths wore sound. I had also about an acre of the same kind on land which had been trenched last year, and which never had carried a crop. It was manured with farm-yard dung and ashes. The crop, though affected in the leaves and stems, was nearly all safe in the tubers.

It would thus appear that potatoes grown on new land are less subject to disease. I have seen several varieties of potato recently raised from seed, all of which were affected with taint. The average produce of sound tubers last year in this district, did not exceed from three to four bolls per acre. In very many cases the produce was much less. The disease seems to have affected the potato plant in a particular stage of its growth, and the different varieties were affected accordingly, the late kinds escaping with comparatively less injury. The disease seemed to stop its progress about the middle of September, as it did not extend to more of the tubers after that period. But this may have arisen from the circulation of the juices of the plant having been arrested. The disease does not seem capable of being propagated but in the living plant. I cannot hazard a conjecture as to its cause, but it certainly seems to be produced by atmospheric influence—a predisposition having been in the potato, probably contracted by excessive cultivation, and forcing manures. That atmospheric influence must have been one of the causes, I have not a doubt, as I am aware of an instance of a diseased stem on a hill at the distance of a mile from any other cultivated spot.

The potato from which the stem grew, had probably been carried off by a crow. I stored up my sound potatoes about the beginning of November, and they are still in a sound state. They were placed in a long pit, in the usual way, without any ventilation. 1 have also seen sound and diseased potatoes pitted together, with apparently no bad consequences. A common plan in this part of the country has been to take up every alternate drill, and cover up the others with the plough. This plan seems to answer very well. No chemical application can restore diseased potatoes to a sound state. I know of no remedy for the disease; but I would strongly recommend an importation of potatoes from the country in which they are indigenous.

I may observe, that the mean temperature of last year was 47.73 deg. Fahr., and the quantity of rain 40.65 inches. This temperature is fully 3 deg. above the average mean of this district, and the amount of rain ten inches more than the average quantity.

No. 3.—Mr Peter Paton, Fraserburgh, 5th January 1847.

The taint on the potatoes first appeared about the 1st July 1846, after a fortnight of excessively hot foggy weather, such as made respiration difficult to human beings. The part connecting the leaves lost its strength; then the leaves grew black, and the stalks presented the same appearance that bean-stalks assume when ripe; the tubers, as the leaves fell from the stalks, became discoloured in the skin, and this proceeded more and more, daily, until they bad the appearance of a rotten apple, but still hard. If there happened to be any safe potatoes, they were invariably the lowest. The flowers fell off the same as the leaves; few of them attained perfection. None of the varieties have entirely escaped the disease; but the long blue has suffered least in this quarter. Those lately raised from seeds have been equally affected with those long grown from the tubers. In new ground of a poor description, with a mixture of black sand and mossy soil, they have been less affected; in rich soils, especially black, they have been the worst. Many of the potatoes have been left in the ground, and such as have been taken up, have been pitted in long narrow pits, and mixed up with earth, approaching as nearly as possible to the state in which they grow, the tainted being carefully separated from the safe, they being easily distinguishable from the colour of the skin. Many of the tainted were converted into farina at the end of the harvest; but such as were allowed to remain under ground, have entirely disappeared.

No. 4.—General Byres of Tonley, 15th January 1847.

The disease was first observed about the 31st July, a few days earlier than it made its appearance on other potatoes in the neighbourhood; which may be accounted for by their having been earlier planted, and farther advanced than on other farms around.

The long white kind was affected about a week before the other varieties; but the others suffered equally when about the same stage of growth. One kind, that had been raised from plums, at Tonley, and grown for eight successive years, were also affected, but were about a week later in being so than any of the other varieties, and suffered fully as much as any.

One part of the crop was upon good old land, a part of which was planted with long whites, manured with bone-dust, and not a single potato was saved. Another part was manured with guano, of which about a fourth part was taken up safe. Another part manured with farm-yard dung, yielded much the same quantity of safe potatoes as the guano, but were rather larger in size. Another part of the crop was upon newly improved land, which had not previously grown potatoes, though one or two crops of tares had been taken from it. The tops of these were affected about the same time as those on the old land; and although the potatoes made no progress in size afterwards, there were not nearly so many actually bad potatoes as upon the old land, and probably rather more than half an average crop was secured, and stored partly in pits, with alternate layers of earth, and partly left in the drills and covered up. From a late inspection both seem to be keeping perfectly well.

On another part of the estate, a small patch of ground, newly improved, on a hill side, at a considerable elevation, the potatoes were affected with disease in the leaves and stems, later in the season, but about the same stage in growth ; and although the disease extended to the tubers, a larger proportion was perfectly safe, than has been found in either old or new land at a lower elevation. They are of excellent quality, and continue to keep good, having been stored in round pits covered with turf and earth in the usual manner.

No. 5.—Mr Hugh M'Connach, Secretary to the Vale of Alford Agricultural Association, Alford, 27th January 1847.

In the year 1845, the potato disease was unknown in this part of the country ; the case, unfortunately, is now far otherwise. This mysterious and destructive disease was first observed in this quarter about the 2d of August, last year, in a small plot of early potatoes, in a garden on an elevated situation, where mildew or any thing of that nature would have been least expected. In this case the disease had made some progress before it was observed. On the 8th August, symptoms of disease showed themselves in a small field, distant about 3˝ furlongs from the first mentioned place, which had been planted pretty early in the season with common potatoes, and, up to that date, had a most vigorous appearance. As this field was every day carefully examined, the disease was noticed in what was believed to be its first stage. It commenced by attacking a single leaf near the top of the stem, here and there, in one drill, and these leaves had a withered, shrivelled appearance, as if their hangers had been broken or destroyed by a strong breeze of wind. About two days afterwards, the disease developed itself more visibly in a single spot of the field, nearly two yards square, where the whole leaves and stems became quite black and faded in the course of a few nights, and it rapidly thereafter extended itself over the whole field, and indeed over the whole vale of Alford. The rot in the potatoes seemed to commence simultaneously with the decay of the leaves and stems. The flowers in this instance were off, and the apples formed before the disease appeared. The tubers had not, however, attained their usual size. They often appeared sound till the skin was broken, and then they had the appearance of a chipped apple, and the appearance soon spread over the whole potato, which became a rotten mass. The weather during the whole season had been extremely sultry with a great deal of thunder and lightning, which brought occasional heavy showers ; but the temperature, though high, was equable, and the season on the whole was not what might be called rainy; nor was there anything remarkable in the state of the weather at the time the disease made its appearance, except the excessive heat. On the 6th of August, however, there was a pretty dense fog over the country.

It may be worthy of remark, that in the second instance above mentioned, the leaves first attacked were observed to be all on one side of the drill, namely, the south side—the side next to the garden where the disease first appeared. Are we to infer from that circumstance that the disease had been communicated by the atmosphere from the one place to the other—the one infecting the other at a particular stage of the crop?

Various attempts were made to check the progress of the disease on its first appearance. Some spread quicklime over the stems—others pulled them up— and some cut them off; but all without any good effect. One individual diverted a strong current of water from its course, and thoroughly flooded his field, but the more sudden decay of his crop was the result he reaped.

The only variety of potatoes cultivated in the vale of Alford, that has been less affected than the others, is a round light red or pink potato, not known here by any particular name. [Probably the variety named cups.—Edit. ] Some varieties are more or less injured than others, and some are nearly extirpated altogether. On a small plot of ground with a running stream on one side of it, and a wood on the other, some long blue and long white potatoes were planted, and not one in a hundred of their tubers was affected; but these were raised from the ground as soon as the disease appeared on the leaves. The ground had been brought into cultivation four years ago, and had then carried one crop of potatoes. On the other hand, the same sort was all but a complete failure in another field, which had been for many years under cultivation, and the only difference of their treatment was, that those saved were planted about a fortnight earlier than those which were lost, and were immediately raised from the ground on the disease making its first appearance. Some long black and long white kidneys, and some round red, speckled-with white, potatoes, were planted on woodland that had been trenched two years ago, and had carried two crops of oats. Of the long black, between a quarter and a half of the crop was safe. Of the long white there was fully one half safe, and scarcely one of the round red was injured. But the crop was inferior in point of size and quality.

The potatoes planted in this Vale have been long raised from sets or tubers, and there was within it, last year, perhaps no instance of potatoes being planted that were recently obtained from seed; nor is it ascertained as a fact that "any particular condition of the soil, as wetness, previous cultivation, or the kinds of manures used, appear to have had any influence in promoting, retarding, or preventing the disease," unless the above instances in new land may be regarded as exceptions. For the disease may be said to have been universal in this quarter; and no real cause can be assigned for its vagaries. The latest varieties, however, and the latest planted, were on the whole the latest in being affected.

The modes employed in this locality in storing last year's crop of potatoes, have not been numerous. In many instances the crop has not yet been raised—partly on account of its almost total failure, and partly from a belief that those potatoes which may have escaped would keep better in their native beds than otherwise. The few that have been raised have been in general stored in the usual way. In one case some were laid out in the sun till they were thoroughly greened—being carefully picked during the greening. They were then placed on a loft. They have been occasionally turned, and, being sufficiently covered with straw to protect them from the frost, they are keeping quite well. In another instance where the potatoes were similarly treated, and afterwards gathered into a heap, and slightly covered with earth, they soon became useless, probably owing to their not having been earlier raised from the ground, or not sufficiently greened. Those, after being picked, laid on wooden floors, and some mixed with soot in the pit, appear at present to be in a healthy enough state. The disease seems to have abated about the beginning of November.

AYRSHIRE.

No. 6.—Mr Brown of Lanfine, 5th January 1847.

In the Journal of Agriculture published in last October, a short account is given of the potato disease as it occurred in autumn 1845, in the parishes of Galston and Loudon in Ayrshire. During this last season, viz. 1846, this singular calamity has been much more severe and universal: in fact, in this district it nas very nearly amounted to a complete failure.

On minute inquiry regarding the growth of potatoes from the plum, I learn that this plan has been attempted in this neighbourhood in four instances.

1. James Gilchrist, one of my workmen, separated, dried, and sowed the seeds of the potato in the spring, seven years ago. At the end of the third season he had several varieties, one or more of them of good quality. These were carefully attended to, and produced healthy plants; but in 1845, when the disease to an alarming degree appeared in this county, these potatoes from the seed were as bad as any other. This was so completely the case, that although the experiment had been attended with trouble and interest, Gilchrist made no further attempt to preserve the potatoes from seed separate from the others. They were all mixed together in the unfortunate crop of 1846.

2. Andrew Dykes, another of my workmen, planted seeds in spring 1845. By the following autumn he had small potatoes of the size of pease. Of course these were of various kinds, but, without being questioned on the subject, he says that he found a number of these minute seedlings with traces of the disease on them. The small tubers which were sound, were again planted during last spring. In August the potatoes were as large as plums. The stem, however, became diseased in the same manner as those grown from the set. The roots were allowed to remain in the ground, as was done with other potatoes, with the view of preserving them, but when examined a week ago, they were found entirely decayed. The row of plants extended to about 30 feet, but there were no remains of sound potatoes ; there were only a few decayed fragments.

3. Thomas Aird, a weaver, in the parish of Darvel, near my residence, in last March, following the directions given in an essay on the potato by Arthur, sowed the seeds of the plant in a hotbed in his garden. In May the stems had grown to the height of three or four inches. He transplanted these in his garden in the open air. They grew well, and promised to be a fair crop. In August the tubers were as large as plums, but, under the influence of the blight which prevailed at this time, the steins decayed. When examined, in October, it was found that there were only a few scattered roots free from disease—all the rest were quite decayed. The plums on which this experiment was made, were obtained from the partially diseased potatoes of the former season of 1845.

4. John Young, one of my tenants, seven or eight years since, sowed seeds in the spring, and in three years, in the usual way, he had full-sized potatoes. This season, as well as the last, these have been entirely free of disease. A few of them were brought to me some days ago, which looked quite sound. It is a firm red potato, rather of an angular form, with the eyes more sunk than usual. [Properties characteristic of the cups.—Edit.] It is a late kind, and I believe of an average quality as to dryness and abundance of produce. The crop this year extended perhaps to the eighth part of an acre; which was surrounded by potatoes blighted in the usual way.

I have not been able to hear of any more instances near this, than these four, in which the potato has been propagated from the plum. It is quite evident, however, that although this mode of propagation may have been successfully practised in former seasons, this last year, in this district, it has entirely failed. In fact, all the stems were blackened and decayed in the month of August, long before the plums were ripe; and of course these could not have produced fertile seed, or been employed to form new varieties. No doubt seeds may be brought from districts, or from distant countries, where the plums have been allowed to ripen, and where the disease has not appeared; but even under such favourable circumstances, we are informed, I believe correctly, that much time and careful selection are required before we can produce a valuable variety of potato. We are told that the varieties from seed are very numerous; and although, with the assistance of a hotbed, we are able to produce full-sized tubers in one year, yet, as at first, not having two potatoes of the same quality, it becomes a matter of time and difficulty to determine which varieties are valuable and which worthless. It is evident, then, that many years must be required before valuable varieties can be extended over the country. It may happen, too, as was the case with us, that good varieties from seed will not be able to resist the deplorable taint which has prevailed, and which may again assail us.

The growth of now varieties from the seed, in former times, has been highly important, and has created all those valuable kinds which were lately in cultivation ; but from the uncertainty of success, and the long time required to prove them, it is not calculated to afford a speedy remedy for the present calamity. This severe frost (December 1846) may perhaps have more effect than anything else in checking the disease, for undoubtedly since 1837 the winters have been unusually mild.

This disease has been uncommonly severe in this district of Ayrshire. In fact, it has amounted nearly to a total failure, and has already produced severe privation to a very numerous population in our villages. My own estate is exceedingly varied in soil, exposure, and in elevation above the sea, and in former times was rather celebrated for the crops of potatoes it produced. Some land at an elevation of 600 or 700 feet, rescued only last year from the moor, and growing potatoes for the first time, produced as many diseased as in any other situation. In a few instances, a scattering of sound potatoes have been obtained. One farmer on high ground, had about two bolls of sound roots, where in former years 70 bolls was the usual crop. In a few other instances, a very small proportion of the crop was sound, but these exceptions are of little consequence.

The crop intended for my own family occupied about five English acres. In this field, a number of trials were made of different varieties of potatoes, all from the set. Different manures too were tried. From one variety of an early kind, occupying about half a rood of land, we had about 1-12th of the usual crop sound; but, with this trifling exception, all the rest of the field was a total failure. When we ploughed the ground, we found only a few fragments of diseased potatoes.

There has been a marked difference in the appearance of the plant of 1845 from that of 1846. In the former, the leaves and stalks were only partially blackened in spots; the greater part of the plant being nearly in its usual state of verdure. It however decayed sooner than in common seasons. But in this last year, early in the month of August, without any frost, the plant became entirely black and rotten. The decay took place in some varieties a few days sooner than in others, but by the middle of August there was not any exception to the decay. Even the stalks of those early potatoes of which part of the roots were untainted, became diseased with the rest; but in these, of course, the growth had been completed before the severe blight came on, and in this way a proportion was sound.

About an acre of ground was planted with potatoes from Strontian in Argyleshire, apparently quite sound; the crop from these here was as bad as any other. The stalks and leaves of all the varieties of the potatoes looked quite healthy and vigorous in June and July. Early in August they began to become black and withered, and in a few days were quite dead. With us, this sudden change took place very soon after a heavy fall of rain, in which two inches of rain fell in a few hours on the 8th of August (1 inch and 9-10ths of an inch, as measured by a rain guage.) In a few days after this, the stalks were decayed; but whether there was any connexion between this fall of rain and the blight in the potato, cannot be settled. The coincidence in point of time was remarkable.

The above is nearly a copy of the observations which were sent to the Royal Dublin Society some weeks since. At that time it was not known that the Highland and Agricultural Society intended to collect more information than they had done ; and as it is believed that at the present time these facts are of importance chiefly in lessening our confidence in the propagation of the potato from the seed, it may be proper that these should also be in its possession— more particularly, as it is unknown whether or not they may be made use of by the Royal Society of Dublin.

The facts connected with this subject wore collected with some trouble. Since they were written, those examples of propagation by the seed have been carefully scrutinised, and I learn that they are quite accurate. Other reports of the same nature were in circulation, but on inquiry it is understood that the four experiments related are the only ones which have been made in our immediate neighbourhood.

A few detached circumstances connected with the potato disease may perhaps be worth noticing.

From the impression that the immediate contact of the manure with the set favoured this disease, in fully an acre of land the manure was carefully ploughed into and mixed with the ground; but there was not any difference in the state of the disease. It was said, too, that guano was injurious, but in our field this manure was not employed. We used farm manure, dunghill ashes, and also scrapings of roads.

In 1845, in one small mossy field the disease was more than usually marked, and to such an extent, that a great number of fragments of potatoes were scattered about and remained in the ground. This same field last spring was sowed with parsnips. These grew as usual, but the ground was almost covered with potatoes which had sprung from the remains of the former year. There was, in fact, a full crop of potatoes of vigorous growth. Those decayed in August along with the crop in the larger field; and when their roots were raised, they were as bad, though not worse, than those which had grown from sets apparently sound. It may be mentioned, that the crop of plants from these remaining fragments was so abundant, that they were allowed to grow rather than the parsnips. The disease in the tuber was nearly similar to that described in the former year, though much more extensive. There were hollow ulcers surrounded by induration of the substance.

It. has been mentioned, that of all our crops, we only saved a small proportion of early potatoes which had grown in the field. We had also early potatoes of the same kind (named American early), in two plots in a walled garden. In July these were of excellent quality for the table. Their stalks became decayed along with the rest. When dug in the month of October, it was found that in one of these plots in the garden the tubers were entirely rotten, but in the other were a few entire potatoes. This is mentioned to show how apparently capricious this disease is.

Regarding the preservation of the potato through the winter, the belief still continues that if they are raised, they are best kept by having them carefully separated by earth or charcoal. Unfortunately, however, we had no roots for preservation, except a few early ones.

No. 7.—Captain Montgomerie, R.N., Brigend of Skelmerlie, 18th Feb. 1847.

I planted in the end of January and beginning of February, half a field lying-near the sea, and not much above its level, with Taylor's 40-fold, the seed of my own saving from crop 1845, and the rest of it about the end of March, with three kinds obtained from the Orkneys. The same seed was also planted in a field about 200 feet above the level of the sea, the soil of both being light, though the low one was much superior in quality. I also planted on the low ground some seed from the Azores, and sowed some from the plum of 1845. I never saw more luxuriant crops than all these promised previous to flowering. The 40-fold fully realised my expectations, but with the exception of those left for seed, were sold before the disease made its appearance. This took place suddenly about the 8th of August, and in the first place among the Orkneys in the low field; and I may state as a general remark—and I paid considerable attention to the subject—just as the flower was coming into full bloom, all not being attacked at the same time, though the three kinds coming mixed were planted without separation, the upper field did not suffer in the least for fully a month later.

Very soon after the disease made its appearance in the 40-fold left for seed, I had the shaws drawn out, and though the drill was pressed down with the foot at the time, the tubers had by this means been brought near the surface; and after the first unexpected hard frost when lifted, though few escaped being totally spoilt by it, there was near an average crop. I cut the shaws of some at the same time, but the drawing them out appeared to be a much more efficacious method of preventing the disease extending, or rather descending, to the tuber; indeed I am inclined to think it was an effectual one, from the following corroborative circumstance: while digging alongside a wall late in the spring, where some 40-fold had been planted in 1845, and very imperfectly lifted (with the exception of about a perch), long before the disease made its appearance, not one of those left in the ground, above half a boll, was diseased, whereas the perch left till after its appearance were very much so. I remarked that while the leaves only were affected, the tubers were sound, and occasionally even when the stem was slightly so; but as soon as the disease had descended about half way down, we were sure to find them more or less affected; at the same time the seed was in all cases quite sound. For reasons not necessary to explain, nearly the whole of the low field alluded to was two successive years in potatoes; and though I did not collect the diseased ones off, even where most abundant, I saw no difference in the crop, nor do I think soil, situation, or manure, made any; if there was any, perhaps the deepest part was the best. In examining the potato crop left in the ground about the beginning of December, I found no diseased ones in the low field. In taking up some lately in the high one, I found several in which the disease had commenced, and appeared to have been suddenly arrested. I may add, that I planted some perfectly sound 40-fold seed in soil which had not been in crop of any kind for at least 40 years, and they suffered as well as the rest.

CAITHNESS-SHIRE.

No. 12. - Mr Henderson, younger, of Stemster, Thurso, 2d January 1847.

Up to the beginning of August, the potatoes appeared everywhere more luxuriant and healthy than usual; but about that date, the disease, which was formerly unknown here, was observed on the eastern side of the county, whence it extended to the west coast; many parts of the interior not having been affected for at least a fortnight later. The leaves presented the scorched and blackened appearance usually caused by severe frost, but with this difference, that spots often not much over a yard in diameter were affected, and in some cases the leaves and stems quite withered, before the disease extended to the other portions of the field, which it did most gradually. On removing the skin, brownish coloured spots were found on the tubers, which soon extended, and they became entirely rotten. This, however, was not the case with all the tubers of each plant, some of them remaining sound ; though, from the stems being injured at such an early period of the season, they were soft and small in size, unless where the potatoes had been planted very early.

No variety appeared to escape the disease, though some were less affected than others. Of these may be mentioned the black kidney, and some of the coarser kinds commonly grown for cattle, horses, and pigs. A bed of seedlings, not in the immediate vicinity of any other potatoes, were the first observed affected in this district of the county. Any particular condition of the soil or kind of manure was not observed to influence the disease.

The mode of preserving the potatoes, which has been most generally adopted, is leaving them in the fields with some additional earth heaped over them, to protect them from the action of the weather, which, as they are not grown in large quantities, and as the ground was not required for the winter-sowing of any crop, was perfectly convenient, and at the same time prevented the rotting or rotten potatoes from infecting the sound. In some eases where a small quantity had been pitted in the usual manner with a light covering of earth, they were soon afterwards found a putrid mass; which, however, may have been caused in part by their unripe state, as the disease made little or no progress after the stems were destroyed.

It is deserving of remark, that about the middle of October fresh leaves were in some cases observed to appear on the stems which were not entirely withered; and in one part of the bed of seedlings already mentioned, a bunch of fresh stems came up, and grew to about the height of eight inches, whilst potatoes of a small size were formed at the roots. These facts, with others which have been noticed, would tend to strengthen the opinion that the disease is not inherent in the plant, but has been caused by external agency, probably atmospheric.

DUMBARTONSHIRE. No. 13.—Mr Wallace of Auchinvole, 2d January 1847.

Having embraced in my former remarks every thing that I considered might be of ser\ice in showing how matters stood in this quarter, regarding the failure of the potato crop, I have nothing new to communicate, with the exception of what occurred to a small quantity raised upon my own ground.

A small part of the ground was first set with reds; they were exceedingly sickly, did no good, and were not lifted. The remainder of the ground was planted with cups; and I may here mention that the seed used was picked potatoes from a field that was affected the previous year; they were the reverse of the reds, as they sent forth a short but very healthy stem, and were generally noticed by people when passing as being an exception to other fields in the neighbourhood. Having observed that the blight had attacked the stems of almost every field in this quarter, I determined to try the effect of cutting the stems, conceiving there was little chance of the crop being made an exception. This was accordingly done, and I have to state as the result of the experiment:

1st. That there was scarcely a bad potato amongst them when they came to be lifted. After they were lifted, they were immediately put into a potato house, without lime or any other substance being applied to them, and not a vestige of disease has appeared amongst them.

2. Neither large potatoes nor a heavy crop were expected, as they were slightly manured, even supposing they had been allowed to come to maturity in the usual way. But, as might have been expected, after being deprived of the nourishment afforded by the stem, they turned out small, but there was little difference in regard to the quantity.

3. The potatoes did not show a dry mealy appearance on the table, but rather what is generally termed "waxy." They are well tasted and perfectly sound, and I have no doubt that they ripened in the ground after being cut. The manure used was stable and cow dung.

In conclusion I may remark, that I attribute my success beyond my neighbours, principally to taking away the stem when it was in a most healthy state, and not a blighted leaf to be seen. Others tried the same plan, but they did not give the experiment a fair trial, as they only cut the stem away after the potatoes had shown symptoms of disease. I have reserved the small potatoes for seed, and, if wished, will be glad to afford the Society the result of next year's crop.

MID-LOTHIAN

No. 32.—Mr Main, Overseer, Whitehill, 1st March 1847.

The field on which the greater bulk of Mr Ramsay's potatoes were grown, consists of a strong clay, incumbent on a most obdurate and retentive subsoil. The field was thoroughly drained at 16 feet apart, and two feet deep. When being prepared for the seed, the soil wrought very toughly, the result no doubt of the absence of frost during the winters of 1845-46, and the dry season at the time of planting. I have a few potatoes planted on a light soil, with a sandy and gravelly subsoil.

The disease appeared at the latter end of the first week in August, in the field first named, and very soon after a severe thunder storm. In the second mentioned field, the appearance of the disease was fully three weeks later, and had no apparent connexion with any special state of the atmosphere. In both fields the first indication of the disease was a blackness of the stem at its junction with the soil; presently the stem or shaw lost its freshness of colour; the leaves drooped, blackened, and fell, and apparently the work of destruction was com-plete. The blossoms, however, were a curious exception ; the otherwise prostrated plant supported its blossoms, and produced its fruit, and I have now a quantity of the apples from these diseased plants, preparing for being sown as new seed this year. In many instances after the leaves and blooms had totally disappeared (the latter in their natural course), the apple was the only fresh green thing to be seen about the plant; nor could I say that these were precipitated to maturity. I had them plucked from the plant about the usual time. I may also add, that the apples, and the seed they contained, seemed as fully matured, and as free from any characteristic features, as any I had seen from the crop of any previous year. They exhibited no traces of the disease.

With me the plant and the tubers were attacked simultaneously. I ascertained this fact from examination immediately on the appearance of the disease; and I was thus satisfied not only of the simultaneous, but of the independent action of the disease on the potato itself. The effect of the disease on the tubers was exactly similar to that of last year. The part affected presented outwardly a dull appearance, and, when cut, had all the characteristics of a bruised apple. This was in the first stage of the disease; afterwards the whole became a putrescent mass. I submitted some diseased and healthy potatoes to examination with the microscope, and I shall shortly state the result. In an apparently sound potato, though no discolouration was visible, there appeared, suspending itself over portions of the surface, what I would call a light cloudy transparent humour, through which the cellular tissue was distinctly visible. In other potatoes in various stages of the disease, this cloudy appearance was continued, and precisely in the degree of density and darkness of colour attained by the humour, could be marked the progress of the disease. This humour was not suspended over the whole surface, but hung in masses; and, except in the portions of the surface on which it appeared, the cellular tissue, though discoloured, as the humour became so, was visible and entire. The portions of the tissue on which the humour appeared, became, as it were, gradually incorporated with the latter, till the whole presented a mass of corrupt and foetid matter. In fact, so far as I could discover, this humour appears to be the agent of destruction. As it advances to putrescence itself, it carries its victim along with it, till all is involved in one common ruin. What is the nature of this humour, or how produced, I am not competent to say ; I can only state the fact as I observed it. I may add, however, that it is apparently inorganic, or at least my instrument was not sufficiently powerful to detect any organism in its structure.

I am not aware that any of the cultivated varieties of the potato have escaped the disease, nor, with the exception of the Irish cup variety, that any have been, on the ground of variety, less affected than others. The Irish cup is apparently our hardiest variety. On many fields in which buffs and blues and dons were all equally destroyed, the cup stood bravely out; and though at last it met the fate of its neighbours, it still yielded a comparatively fair return. The disease affected the yam in much the same degree as the Irish cup.

I am aware of two instances in which potatoes recently obtained from seed were planted, but they exhibited no advantage over those "long raised from sets or tubers." All were alike affected. In both instances, the farmers who grew them asserted that they resisted the disease longer than the others, but with no other advantage. This told little in their favour.

I have already stated that the potatoes grown on my heavy land were earlier attacked with the disease than those grown on my light soil. But this was not the only advantage of the latter; for, while from three acres of heavy soil I did not lift more than one boll and a half of potatoes, good and bad, from the light soil not extending to more than one imperial acre, I lifted five sound bolls. The latter is certainly no great result, but it tends to prove that in light soils the taint had less power over the tubers than in heavy ones; and my own experience has been confirmed by that of all my neighbours. In every instance I am aware of, the light soils had the advantage of the heavy ones. All were attacked, but the light at a later period, and in a less degree, than the heavy.

No "previous cultivation," nor any kind of manure, had the slightest apparent effect on the disease. I grew my potatoes with a great variety of manures—specific and farm-yard, both kinds alone and in mixture—but the crops from each were all alike affected. I had some planted with sulphuric acid absorbed in sawdust, and applied with a proportion of some manure, and I was in hopes that would have some effect; but though I watched closely, I could observe none. The fact is, no circumstance connected with the potato, so far as I am aware, had any influence in retarding the disease, with the exceptions I have already stated, namely, the cup variety of the potato, and light soils, and I may add whole sets. I had about an eighth of an acre planted with whole sets; and these, long after the crop from the cut sets was blackened and prostrated, flourished green, but certaintly not healthy. But in whatever way and to whatever extent the disease was retarded, or rather its effects ameliorated, no influence of any description, that I am aware of, operated to prevent it.

Very little can be said about the modes employed in keeping or storing the potatoes. The crop in this neighbourhood was so very small, that the greater part was at once consumed; and those retained for seed—probably not more than two or three bolls on each farm, in some eases not so many—were in general pitted in the old way, from necessity, in very small pits. In my own case I gave my small pits as much air as possible, by means of straw ventilators and frequent turnings. Till this date the potatoes are keeping well, though at every turning a few are thrown out diseased. Out of from three to four bolls pitted, I will probably be able to plant two and a half bolls, and these are all I intend to plant this year. I should have stated before, what I now add, that, previous to pitting my potatoes, I had them laid thinly spread in a cellar, and turned frequently; and it was not till they were considered sufficiently dry from this process, that they were put into the pit.

I have already stated that the disease had an independent action on the potato, and did not appear to depend on generation. I may now state some facts in support of this. On my first examination of the potato immediately after the disease appeared, I found that the potato, as well as the plant, was affected, and that in the majority of instances the disease did not appear at the "root," but at the "rose" end of the tubers. This was not the invariable, but it appeared the predominating rule. Now, had the disease been conveyed to the potato from the plant, the natural inference is, that the end of the potato attached to the ligatures connecting it with the plant, would have been the first to exhibit the appearance of the taint. That such was not the case, demonstrates to my mind that the potato did not depend on the plant for the communication of the disease. True, the disease did in some instances exhibit itself at the root end, but the instances of its appearance at the "rose" end, and on the sides, were more numerous, and of necessity compelled to the conclusion, that the appearance of any part of the potato was not the result of propagation from the plant, but a direct and immediate attack on the tuber itself. Another fact opposed to the theory of propagation is, that the root of the plant was in every instance, which I examined, the first to be attacked. Immediately on perceiving the black appearance above ground, I examined the root, and I found it completely diseased. The colour was of a dirty yellow, and the outer rind hard and brittle; approaching the extreme end, the root had the appearance of rotten wood, and rubbed to atoms betwixt the fingers. From this fact I demonstrated to a neighbour farmer the inutility of cutting over the shaws. He had performed this operation at once when the disease first appeared above ground, and he was not a little surprised when he found that the root was even worse than the shaw had been. In my own case, as an experiment, I pulled eight drills of potato shaws from the crop grown on the light soil, but it did not advantage me anything; the crop from the pulled portion was equally bad as that from the rest of the field, when the shaws were allowed to remain till the lifting time.

And as from the above facts I am of opinion that the disease is not one propagated from the plant above ground, so neither does it seem to depend at all on the condition of the seed. I shall state two facts in support of this. I have already stated that I planted about the eighth of an acre with whole sets. On the appearance of the disease among these, I pulled a shaw for the purpose of examining its roots and the crop of young potatoes. In pulling the shaw, the parent potato came up with it; and what was my astonishment to find it perfectly sound, while the root of the plant, and four out of six young potatoes, were diseased! The parent potato was soft and pulpy, but though I cut it into minute slices, I could not observe a single trace of the disease. The other fact is of an opposite character. I planted in my garden five diseased sets, two of them very bad; only one of these grew, but it was one of the two worst. When the plant appeared above ground, it showed a dark healthy colour, and progressed favourably: in fact it had a much more healthy appearance, and certainly a more luxuriant growth, than plants immediately beside it, the produce of sound sets. This plant fell with the rest before the destroyer, but as it had grown more vigorously, so it resisted for a longer time than the others, the attacks of the disease. These facts prove that the sets had nothing to do with the disease ; in fact, it did not appear in either case, till young tubers were formed, and the plant itself was deriving independent nourishment.

These facts in my own opinion disprove all the theories founded on atmospheric influence, and point, if any pointing can be true, to the soil as the seat of the disease. Immediately after ascertaining these facts, I decided that the absence of frost in the winter of 1846, and the small amount we had of it in that of 1845, was the cause of the disease. I argued, that, without frost, the land lying wet and souring, would generate noxious gases, which, independent of their individual action, would form hurtful combinations ; these, absorbed by the potato, would speedily destroy its vitality, and of course result in its destruction. Of course in this case a natural inference is, that light or dry lands would not be so much affected as heavy or wet ones; and such an inference is quite in accordance with my experience. Again, the plant would not be affected till left by its parent to sustain itself; such I have proved was the case. And again a third conclusion from these premises is, that the peculiar construction of the tuber left it independent of the plant in receiving the disease, and such I have proved was the fact. But, specious as this theory appeared to me, I confess I am somewhat shaken in it since the appearance of the disease this year. The papers record several instances of its re-appearance, I will now state an instance in my own experience. I had saved some healthy tubers of what I considered a peculiar variety, and had them placed in a small pit. On opening the pit a few days since, almost every potato had a young growth of tubers attached to the eyes; some of these young tubers were about half an inch in diameter, and those attained to this size were diseased. The curious fact was, the parents were perfectly healthy, but soft. These potatoes had been enveloped in straw, and had no connexion with the soil, nor as little had they any with the atmosphere. What produced the disease? I cannot answer the question, and certainly it staggered my faith in my own theory, while it more completely demolished all others with which I was acquainted. In the mean time, it were well to resolve the whole mystery into the workings of an inscrutable Providence, and find in the faith and hope of His mercy, a better prospect for the potato than we can find in the fanciful theories and vain speculations of the human mind.

Still, while the disease is held to be a dispensation of Providence, it is nothing impious to suppose that this dispensation is in connexion with natural causes, and that some physical law of nature may yet unravel the mystery. I would then continue to investigate. Let earlier, the very earliest opportunities, be taken to observe the young plant, and note carefully the results. It would also be useful to plant potatoes on various soils, and even to prepare soils for the purpose; that is to give them the qualities supposed to affect the plant favourable or the reverse ; and thus by close, early, and careful observation, some light, however dim, may be cast upon a subject at once so interesting and important.

I may just add, that the second growth was a very curious phenomenon. It appeared with me about the first week of September. The first indication was a few leaves at the extreme top of the shaw; and on examining the root, I found some young tubers at no depth in the soil, but they were diseased. New roots were struck out from the otherwise withered stem, but the influence of resuscitating life was but of short duration. Indeed, the new life seemed confined to a very small portion of the "pith" in the heart of the stem, which, continuing to possess a degree of activity, had, from the long time it continued in the ground . after the first dormancy of the plant, put forth a feeble power. This, while it is certainly a curious fact, affords a strong proof of the tenacity of life in a plant. Strong hopes were expressed that this second growth would produce at least a sufficiency of seed, but these hopes were founded on hasty conclusions. Long before, theorists had discovered the fact of the second growth, and built their fine-spun speculations upon it. Practical men were aware of its existence, and had been taught its usefulness to themselves or the country.

I do not think the disease is contagious; the facts I have stated in reference to the potato plant grown from a diseased tuber, are proof of this; for, though it became subject to the taint, it only shared the fate of other plants grown from sound sets, and there were no indications about it which, in the absence of the disease, would have induced the belief that it was likely so to fall. I also tested the contagious report of the disease by connecting the surfaces of diseased and healthy tubers, and allowing them to remain together for some time, but with no effect; the sound remained sound as before.

Postscript, 29th August 1847.

I beg to add a few facts relative to the potato disease, as it has appeared in our field this year.

I can give no precise date for its appearance; and in attempting to fix a date, is, I conceive, one of the errors we fell into last year in respect of this disease. My experience leads me to conclude that it is progressive in its effects, and in its first stages at least, its progress is slow. True, I have heard of, what we all heard of and believed last year, the disease making its appearance in a single night, and effecting its mission in nearly as short a time. But unless it be the most erratic monster that ever walked the earth, leaping over regulating principles, and effecting its object in a thousand and one diversified modes, then I must respectfully submit, that these achievements of single nights are to be received with a proper degree of caution, I had almost said of suspicion. Since the potato plants were a few inches high, I have watched their progress with much and growing interest, and I think I am correct when I say, that since the early part of the month of June, I have observed the symptoms and traced the progress of the disease till now, when the largest proportion of my crop is lying-prostrate under its influence ; and most decidedly my firm conviction is, that it does not do its work in one night, or in two or three nights, or days either.

I shall give a hurried sketch of my observations. Some time in Jane—I cannot give the precise date, but it was while the plants were yet young—I observed a brownish appearance on the root; in some instances this brown colour appeared on two or three parts of the same root, but invariably at the extreme end where it joins the parent set. Towards the latter end of June, the leaves showed indications of soilness, and inclined to curl, or folding towards the centre. To prevent mistake, I may state that this tendency of the plant had no characteristic in common with the disease called "curl:" I had hardly a "curled" plant in my field. At this time, too, the roots retained their brownness, but now rather deeper in the tinge. On the 5th of July I made a careful examination of the field, and the unfavourable symptoms still continued. At this examination I observed a blackness round the edge of the leaf, and the tips of the leaves were very generally black. We had not had any winds up to this date sufficient to account for this appearance ; and it certainly excited my fears; the more, that I thought I could distinctly trace the destruction of some of the under leaves to the progress of this blackness on the edge. On the 9th of July I have noted another examination. I give extracts from my notes:—"Many plants have their under leaves and branches quite black, and at this stage they invariably drop from the stem." "One of the plants I have pulled has only a few green leaves at the top; the lower ones, with their branches, have decayed and fallen off, and the stem presents a dull unhealthy appearance." "The unhealthy appearance on the root is more decided, and at the part attached to the parent appears quite decayed. When cut, the centre presents a blackish appearance." On the 11th of July my potatoes got a final hoeing and were set up, and to a general observer no crop could have a more decidedly healthy and promising appearance. Many persons laughed at my fears; but they would disturb me, for all that. On the 30th July I made another examination. My note states:—"I have now no doubt about the appearance of [he disease. . . . My present conviction is, that the characteristics of the disease are a general decay of the plant, commencing at the root. . I find various appearances of unsoundness. . . . A universal rule is the affection of the root. In some cases of total decay"—I had found thorough decay at this date—"the root is supple, and its whole substance is deeply discoloured. In other cases little discolouration is observable beyond the extreme point; but this never fails. When the root is cut, it presents a hard woody texture, and cuts as toughly as a young ash sapling. . . . Another invariable characteristic is the dullness of the stem above ground, and that although the leaves appear fresh and green." In this note, which is a long one, I mention several indications on the leaves, arguing the progress of the plant to decay. The first is a yellowish coloured spot—next a black daubed appearance, exactly resembling the traditionary mark of St Peter's thumb on the haddock—and the third a black spot. Of this spot I remark:—"Where it is very bad, the whole plant at once manifests its unsound state, and presents indubitable marks of decay." Again in this note I remark:—"The diseased plants are scattered over the whole field. ... A singular characteristic is, the centre and under leaves and branches, especially the centre, invariably exhibit the first symptoms of decay—they are frequently all decayed when the top leaves present no appearance of blackness; on the contrary, though not healthy, they are yet green." The folded and soft character of the leaves is also noted. Without further attending to notes, I may now state that my worst fears have been realised. The progress of the disease was slow, but sure, and now the large proportion of the field is lying under its influence. I fear the whole will go.

I have given extracts from my notes to prove, so far as anything so hurriedly given can prove, that the disease is not immediate in its attacks. Its final consummation is sudden, and it may be in certain circumstances as sudden as is contended for; but its whole history is analogous to several of those insidious diseases so destructive to human life—gradual at first; but, arrived at a certain stage, the thread of life is snapped in an instant, and the being hitherto in apparent vigour, is at once a lifeless corpse. Such is the progress and end of the potato disease.

I will not attempt an argument as to the cause of the disease, nor will I seek to adduce and collate the evidence of its origin; suffice it, that I am more than ever confirmed in my opinion that it is not the result of atmospherical influence. In my opinion it originates in the root of the plant. What I have already stated may be taken as a partial argument in support of this view: I will embrace some other opportunity to illustrate and enforce it.

I may state generally that this year, as last, at least so far as I have been able to trace, no condition of weather, character of soil, kind of manure, or species of potato seed, has had any influence in preventing the disease. What influence any of these circumstances may have in retarding or promoting it, must be de-cided at the conclusion of the season. I have had no autumn-planted potatoes myself, and at this moment I am not aware of the experience of others who had adopted that season for planting. I may state, however, that I planted a few potatoes in my garden in January this year. In April these had not appeared above ground, and on examining them I found fully the one half rotten, but the sound sets had made considerable growth. I lifted and re-planted two rows of these, and in the first week of May they appeared strong and healthy; they have since continued to grow vigorously, and have not exhibited any particular marks of the disease, except in some cases the hardness at the root; but then they are nearly ripe, and the shaws are naturally failing, and the potato plant when ripe has, at all events, a greater hardness at the root than when in the vigour of its growth. I would not like to conclude much from this fact, especially as a portion of the season remains, and my experience before its conclusion may be reversed. However, I am encouraged to try again, but this season I will plant both in autumn, and again early in the coming year. This year I will plant my seed below the dung as a defence against frost, as, to the neglect of this in January, I attribute the rotting of so many of my sets. I would also advise the planting of whole sets. At all events, as an experiment, whole may be tried with cut sets.

I have this year some young plants from last year's seed, grown on a light soil. At this date they are vigorous, and present no trace of the disease.

Except in connexion with the "scab," I have not found any trace of the disease in the tuber. Below the "scab," the same marks appear as indicated the disease last year, but have not penetrated to any depth. I have my hopes and fears.

Such is a rapid sketch of my experience of the disease this year; I shall be happy at another time to fill up the outline I have now given.

PERTHSHIRE

No. 35.—Mr Archibald Gorrie, Annat Cottage, Errol, 17th Dec. 1846.

In 1845, we, in this quarter, heard of high temperature in southern latitudes, followed by excessive rains, and inundations, with simultaneous complaints of decayed and decaying potatoes. That sort of weather reached as far north as the central districts of Scotland, by the middle of September, when drought and heat were followed by complete saturation, and the disease appeared.

I was then deeply impressed with the idea, that heat, followed by excessive moisture, originated and extended the disease. I am confirmed in this opinion by the fact, that about thirty of those correspondents who returned answers to the queries, in reply to the first, mention that the disease appeared after heavy rains; though they do not consider this fact as producing the disease generally. Sir John Richardson, Bart., of Pitfour, Perthshire, indeed says:- "The excessive moisture appeared to me to have aggravated, if it did not cause the disease." This being my impression, I paid particular attention to the meteorological phenomena this season, as connected with the commencement and progress of the disease. It will be recollected that little rain fell in the last weeks of May, this season—potato stems, especially on strong lands, came up small and wiry ; which habit of growth was encouraged by the warm and dry weather during the first eighteen days of June, in which period the rain that fell did not amount to one tenth part of an inch, while the temperature frequently rose above 80 degrees Fahrenheit. The average temperature for the first week in June was 70 degrees ; for the second week, 63 degrees; and for the third week, 66 degrees, that is, taking the average of heat and cold for each day; this temperature, with clear sunshine, produced excessive heat in the soil, and evaporation on its surface, and succulent plants, such as beans, potatoes, &c, began to languish. On the 19th, a full inch of rain fell, and by the 19th July, in the short period of thirty days, the fall of rain, with a continued high temperature, amounted to nearly eleven inches—a fall, I believe, unprecedented in the annals of meteorology in this quarter. This highly saturated the warm state of the soil—completely destroying the vegetative functions of the potato, and on strong lands, of beans.

Of the potato, some of the tubers, from their position, were less steeped in warm water than others, and such escaped the disease; but on frequently pulling up the shaw, I always found diseased tubers, some of them not above the size of a grain of barley, completely soaked and rotten, while the rootlets by which they were attached to the stem, were quite fresh. The. blotch on the leaf, which was soon covered with mildew, I considered as merely a symptom of a plant decaying at the root.

I have asked some eminent horticulturists, if by imitating the meteorology of June and July, as far as heat and moisture were concerned, by artificial means, they would not at any time produce a disease on succulent tuberous rooted plants, similar to the potato taint, and have been always answered in the affirmative. Beans generally thrive with an ordinary degree of moisture, but this season the drought in May and the early part of June, so compressed the soil about the neck of the plant as to render that part under the surface much smaller than where it swelled freely, immediately above ground, whilst the continued rains gave the feeble rootlets more moisture than they could absorb, and by the end of July, the outer cuticle was completely scalded, and came off with the slightest touch. The success of beans this season was just in proportion to the porous nature of the soil on which they grew.

I am aware that former seasons will be referred to, and the year 1826 will no doubt occur to objectors. Let us look to the meteorological registers kept at this place for that year. In the month of June that year there was not a drop of rain, and the mean temperature for the month was 63 degrees; the average or mean for the corresponding month this year, is just one degree higher or 04. In June 1826 there was no rain; in June 1846, five and a half inches of rain fell on the eleven last days of that month.

In July 1826, the mean temperature was 63° 9'; in July 1846, it was 60° 5'; in July 1826, the rain that fell measured 1 inch and 9-10ths; in July 1846, 5 inches 7-10ths; in August 1826, the mean temperature was 61° 4'; in August 1846, it was 61° 8'; in August 1826, the rain measured 1 inch and 95 decimal parts; in 1846, 4 inches 7-10ths. "When it is known that the average fall of rain in the months of June, July, and August, does not much exceed six inches for the three months, and the annual fall averages about twenty-seven inches, it may be expected, that from the excessive rains during that period when the potato was growing this and last season, it is not to be wondered at, that the potato and bean plants have been what gardeners call damped. Having taken up so much space with the first query, my answers to the rest shall be brief.

White Americans, London dons, and Yorkshire reds, raised on peaty soil, on a high hill, are mostly safe. Perthshire reds nearly all diseased. The reds, too, I am informed, are most liable to the disease throughout Germany.

I sowed seeds of the Peruvian kidney, and treated them with great care, but all the young seedling plants gave way in the end of July.

I am confirmed in the belief that the disease can be communicated to sound tubers when the temperature rises high in a pit, by the ordinary process of pitting, and that heat accelerates the infection. I have found that a calcareous sand to which I have access (storing the potatoes in the same way as is usual for gardeners to store carrots), keeps the potatoes separate, the pits cool, and prevents infection.

ZETLAND

No. 43.—Mr Duncan of Tow, 15th February 1847.

The potatoes in the district around me, my own inclusive, were perfectly unscathed till about the 12th of August. They were looking beautiful, and we had all begun to take a few out of the ground for immediate use ; and I was so satisfied with the appearance and quality of mine, that I was congratulating myself upon the real store of fine potatoes we should have for winter consumption. About this time it was reported that the disease had appeared in the southern parts of the parish of Dunrossness, about 12 or 15 miles distant from us in a southerly direction, but which did not alarm me much, as, having escaped its attack in former years, I thought I might do so again. In a few days, however, I was told that my nearest neighbour, immediately on the south of me, had observed that his potatoes were in an unsound state. I went directly to look at them, and found that a portion of them was completely destroyed, and that the leaves of the rest were all becoming brown-spotted. Till now, mine continued to look well; but being told at length by a gentleman who had noticed them more particularly than I had done, that they too were affected, I went and examined them, when I found the gentleman's report to be too true. The disease was then discovered to have spread over the whole district, no part escaping; and, in a short time, nothing was left of the shaws but the stems, blossoms and leaves having all disappeared together. The weather was intensely hot at the time, and continued so for some time after—the wind light, and, according to my present impression, in the southern quarter of the sky, though at this distance of time I am unable to speak with certainty on the point.

What I have thus stated with regard to appearances in this district, will apply, with little variation, to the whole of the Zetland Islands. The potato crop every where suffered in the same way, and from the same cause, whatever that cause might be; but whether the agency of the wind may be supposed to have had any influence in spreading the disease, is a point which I must leave to others to determine. The solitary fact which I have mentioned, even supposing the wind to have been blowing from south to north at the time, seems to prove nothing to the purpose; as, about the same time that the disease manifested itself in Dunrossness, reports were in circulation that it had also made its appearance in the parish of Tingwall, eight or ten miles north of this district. In fact, it is a matter of doubt to say where it began, as it seems to have overspread the whole group of islands at once.

The tubers when examined had the appearance, as I formerly stated, as if they had been scorched with fire, and when boiled whole, emitted an offensive smell. The disease had not, however, in the majority of cases, carried its effects into the centre of the potato; and when the damaged parts were removed, what remained was as fine as could be wished.

The refuse, which served for feeding pigs and poultry, was readily eaten by them, and found to agree. The parts underneath, where the skin presented the scorched appearance above described, were blackened, but there was no absolute rottenness; on the contrary, the damaged parts felt rather hard and dry. In some cases the injury had gone deeper into the potato than a third—so deep, indeed, as to destroy it altogether. It is quite common, after the potato—the portion of it deemed fit for use—has been boiled, to observe dark-coloured lines, terminating each in a point, extending inwards from the circumference, where the disease had established itself towards the centre, as if they had been formed with a small-pointed instrument, with some sort of colouring matter upon it.

I may now mention, from what I have seen, that the disease, in my humble opinion, has not taken its rise from any bad quality in the potato itself, but has been owing entirely to external causes, either proceeding from the earth-insects or the atmosphere, but which of these I must leave it to the learned to determine. Some ascribe it to the extreme heat; but in this opinion I cannot agree, as we have experienced as warm seasons before, without any injurious effects to the potato crop.

All sorts of potatoes seem to be cultivated here in a mixed form, chiefly— though I am unable to distinguish many of them by the names by which they are known elsewhere. I think I mentioned formerly there being among some of mine which I raised in the end of harvest, a few of a pale red colour, with patches of white upon them, particularly about the eyes, which had not taken the disease, and made a selection of them, with the view of preserving them for seed this present season, but unfortunately they were lost. I have, however, obtained possession of a few again; and, if an opportunity offer, it is possible I may take the liberty of sending the Society a sample of them. Though grown among the diseased ones, they remained uninjured. My only regret is, that I have extremely few of them.

Through the winter I happened to have occasion to see Mr Mathewson, the schoolmaster of Yell, who had lately returned from the island of Unst, and who informed me, on my mentioning to him the discovery which I had made with regard to my white-eyed potatoes, that he knew a man in Unst who had all his of this description, and that he had not lost one of them last season. I afterwards wrote to him to make further inquiries, and let me know how the case really stood, and lately I received from him the very interesting letter which is herewith sent, and from which it appeared that Bunt's potatoes (for such is the man's name) are of the same sort as mine, to which I have already referred. Where they came from originally is more than I can tell; but if they possess the peculiar quality of resisting the disease, as I cannot doubt they do, they are a great acquisition to those who are fortunate enough to possess them. Some of my neighbours, to whom I showed mine, said their experience coincided exactly with my own.

I scarcely know of any attempts being made here to raise potatoes from the seeds; and it may be stated generally, that those in use now among us are the same, with little variation, that have been used for time out of mind. In wet soils, I have heard—and I believe it—that the potatoes have suffered less than in the dry, though they have not escaped it altogether; and, in some few localities, even where the soil was rich and dry, the injurious effects have not been so severely felt, as in others of the same description. Nothing can be inferred from the mode of manuring the land intended for potatoes; as some people apply manure, and others, and by far the greater number in this district, none—myself excepted. At any rate, the mode of culture was the same last season that it had been from time immemorial; and I may add, that no where, so far as I know, are greater pains taken upon the care and cultivation of the potato crop than in Zetland.

The usual mode of storing potatoes here is to place them in pits in the earth. I warned the people against continuing this plan this last season, as I was apprehensive they would take heat and rot; and the event has shown that my anticipations were well founded, as there are few now left, either for food or seed. The people, for want of other means of preserving them, were compelled to act as they had done before, and they are the sufferers. The few individuals who were at the pains to separate the healthy tubers from the others, have, I understand, succeeded in preserving them, though they are comparatively few in number who have been thus fortunate.

I raised some of mine in the end of harvest: and though I dried them in the sun, when laid in a heap—though laid in a cool place—they immediately took heat, and had to be taken out and dried a second time, before they were considered out of danger. The rest were left in the ground (it happening to bo enclosed) ; and though I am not prepared to say that they are better now than they were at the end of harvest, neither can I say that they are any worse.


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