whole well stirred, till the alkaline sulphates are decomposed. Two methods may be followed in carrying on this operation. The kelp, before it is allowed to cool, may be mixed with the other substance in the kiln in which it has been prepared, and the heat thus kept up till the decomposition is effected; or, after it has become cold, it may be reduced to powder, mixed with the vegetable body, and heated in a furnace. I believe the preferable plan, or at least the one most likely to be followed, is to mix the peat or other vegetable substance with the melted matter in the kiln, as in this, though more of it may be consumed by the combustion necessary for keeping the heat, yet no additional apparatus is necessary, and the labour of breaking down the kelp after it has become consolidated, and reburning it, would be avoided. up It is not to be expected that I can enter into any detail as to the quantity of carbonaceous matter to be added, or the manner in which the process is to be carried on: I merely wish to point out a mode, by which I have every reason to expect, that kelp may be manufactured, which will compete with barilla, with respect to the quantity of soda. Though I have succeeded, in a small scale, in increasing the soda to so great an extent, it must not be supposed, that, when prepared in the common way, kelp will be made having the same proportion of alkali; but taking the average of soda to be about 3 or 4 per cent., if this can be doubled, a very material point is gained, because, with this quantity, it will at all events, even though inferior in real value, compete with barilla, which brings from three to four times the price. One thing I consider the preceding remarks clearly to establish, that the proportion of alkali may be greatly increased after the kelp has been manufactured, and if this be allowed, I cannot see how it can fail to succeed in the first operation, for wherein consists the difference, of reducing kelp to powder, and heating it with carbon, and of at once, when fluid in the kiln, mixing it with the same matter, and continuing the application of the heat? They are one and the same, the result ought therefore to be similar. This subject is well-worthy the serious consideration of the Society. It is through their support that the plan now proposed may have a fair trial, and should it meet with their approbation, and ultimately succeed, I will consider myself amply repaid for the time and labour I have bestowed, if my efforts shall be the means of warding off the ruin now impending over the staple commodity of the Highlands and Islands of Scotland, by which one great source of subsistence must be ultimately withdrawn from the poorer part of their population, and the incomes of many of their proprietors be considerably reduced. ON THE PREPARATION OF THE ZOSTERA OR SEA-GRASS, IN ORKNEY. In a Letter from JOHN TRAILL URQUHART, Esq. of Elsness. SIR, Elsness, by Kirkwall, pre INTENDING to become a competitor for the mium offered by the Highland Society of Scotland for the preparation of the marine plant Zostera or Sea-grass, I inclose herewith, in conformity with the directions contained in their list of premiums, a few brief notices respecting the plant, with the methods used by me in washing, and drying, and preparing it for market; together with an affidavit of the quantity sold, and price obtained; which will be farther corroborated by a certificate from the purchase Mr Johnston, which will be lodged with you by my agent, George Veitch, Esq. W. S. I shall only add, that should the Society see fit to consider me entitled to the premium, a piece of plate, of the same value, if not contrary to their rules, would be more gratifying to my feelings. I have at present nearly three tons of the sea-grass on hand, prepared in a superior manner, which I am very anxious to get to market before the 10th November. When I had the pleasure to meet you in Sanday last autumn for a few minutes, you suggested the idea of my preparing some of this grass, with a view to the introduction of a useful manufacture; and I have since adopted your suggestion, as you see. I am, Sir, &c. &c. JOHN TRAILI. URQUHART. To CHARLES GORDON, ESQ. Dep. Sec. Highland Society, Edin. The marine plant Zostera or Sea-grass is found in abundance in all those bays of the Orkney Islands which are not exposed to the immediate fury of the ocean; and is there known by the name of Mella or Mallow. Wherever the bays are land-locked, banks of sand and mud accumulate, which appear to be held together principally by the roots of this plant, which are strong and succulent, and throw out numerous lateral fibres. The zostera generally grows at such depths as to be left nearly dry by the ebbing of spring-tides. The leaves remain attached to the stem until the month of September; and during the autumn, and beginning of winter, are thrown ashore in large quantities. As this plant floats near the surface of the water, it is always driven before the wind,-unlike the other marine plants of these islands, which (with the exception of Fucus vesiculosus, whose air-vessels keep it afloat) remain near the bottom, and are forced ashore, against the wind, by the groundswell, or reflux of the waves. The sea-grass is used by the inhabitants of these islands as manure for their fields, for which purpose it is either gathered into heaps with other marine plants, and allowed to ferment before being applied to the land, or formed into compost with earth, litter, &c.; in both which ways it is found to answer well. It is also used by the poorer classes of labourers or cottars as thatch for their houses, and in this way forms a good defence against the violent winds and heavy rains of their rude climate, for two years. Its application as a substitute for horse-hair, in stuffing mattresses and furniture, was unknown in these islands, until the attention of a few individuals was directed to it, by the offer of a premium by the Highland Society of Scotland, for its preservation for that purpose, and with a view to its introduction as a useful article of manufacture. |