946 



PRACTICE OF AGRICULTURE. 



burned in a rude sort of kiln, formed by digging a pit in the sand, or by enclosing a portion of the surface 

 with loose stones. On the bottom of this kiln a iieat fire is kindled, and the weed is gradually added, till 



the fire extends over the whole floor ; the weed is then spread lightly on the top, and added in successive 

 portions. As it burns it leaves ashes, which accumulating towards evening, become semifused, and are 

 then well stirred. Another day's burning increases the mass ; and this is continued till the kiln is nearly 

 filled. On some occasions the kiln consists of a cavity in the ground, over which bars of iron are 

 placed ; and on this the ware is burned, the ashes falling into the cavity, where they are well worked by 

 the proper instruments. 



6190. Kelp is generally divided into two kinds; the cut-weed kelp, and the drift- weed kelp ; the former 

 made from the weed which has been recently cut from the rocks, the latter from that which has been 

 drifted ashore. The latter is supposed to yield a kelp of inferior quality. Some specimens of kelp, how- 

 ever, made from sea-weed which had been drifted ashore, tend to prove that this is not always the case. 

 Weed which has been exposed to rain during the process of drying, affords a kelp of inferior quality. It 

 is of the utmost importance to the manufacturer of kelp, to keep his weed as much as possible free from 

 rain. For this purpose many employ sheds; when these are not at hand, thq weed which has been laid 

 out to dry should be collected into one heap during the rain ; when this ceases, it should again be imme- 

 diately spread out. It has often been matter of dispute, how old the plants should be before they are cut. 

 In general, three years is considered sufficient: this, however, from some trials which have been made 

 to ascertain this point, seems to be too long. From experiments, it appears, that the produce of kelp, from 

 one ton of three years' old weed, is only eight pounds more than that from the same quantity of two years' 

 old ; from this we would conclude, that the weed ought to be cut every two years. Though perhaps less 

 weed may be procured from the same extent of ground occupied by weed of two, than of three years' 

 growth, yet the difference may not be so great as to render it worth while to allow the weed to remain for 

 three years. 



6191. In order to increase the quantity of kelp., it has been suggested to the Highland Society, that the 

 seed of the Sals61a Soda might be imported and cultivated at a small distance from the shore, with the 

 design of mixing the plant with the sea-ware, for the improvement of the kelp. It was formerly imagined, 

 that the barilla plant would not produce any quantity of alkali, worth its cultivation, if planted in France ; 

 but in the year 1782, some spirited individuals procured a quantity of barilla seed, and made a plantation 

 of it near the coast of the Mediterranean, in the province of Languedoc, and had the satisfaction for 

 several years to find, that the barilla which they produced from these plants was of a quality equal to that 

 which they usually procured from Alicant. Why, then, may not a similar attempt in our own country 

 be equally successful ? 



61 92. Other j)lants. If the growers of kelp could contrive to make some considerable 

 plantations of the most productive of the kali, or of fumitory, wormw^ood, and other 

 inland plants, which yield large quantities of potash, and collect the crop to burn with 

 the other materials, the carbonate of potash resulting from their incineration would 

 decompose the sea salt, and a great accumulation of carbonate of soda would be produced. 

 It was proved long ago by Du Hamel, that the marine plants produced soda merely in con- 

 sequence of their situation, for when they have been cultivated for some years in an 

 inland spot they yield only potash. 



6193. There are immense tracts of shore on the mainland and islands of Scotland which may be easily 

 cultivated for the production of kelp, from which at present not one penny is derived. All the cultivation 

 requisite is, to place whin or other hard stones, not under the size of the crown of a hat, upon such vacant 

 spaces. Contracts have been made to plant shore lands in the Highlands with such stones, at the rate of 

 20/. per Scots acre. Such stones are generally to be found at high-water mark, on all the shores of the lochs 

 of the Highlands. They are put into a boat at high water, then carried to the ground to be planted, and 

 thrown overboard ; on the ebb of the tide they are distributed regularly over the shore, preserving a clear 

 space of one foot round every stone, which distance, after very minute examination, appears to be the 

 most eligible for producing the greatest crop of ware. It it evident these stones should be of a round 

 shape ; ac the more surface that is exposed to the alternate action of the air and water, so much more 

 kelp ware will be produced from a given space of ground. In four years the first crop may be cut, which, 

 on the above data will yield about four per cent on the original expense. But the crop may be manufac- 

 tured into kelp in every third year thereafter, which, on the same data, is equal to about five per cent. In 

 this improvement there is no hazard of bad crops ; and if the manufacture is begun early enough in the 

 season, there is little danger to be apprehended from bad weather, it being understood that the operation 

 of kelp-making can be carried on, should there be no more than two dry days in eight. (Highland Society's 

 Trans, vols. v. and vi.) 



6194. The cultivation of barilla (Salsola Soda, Chenopbdeae, a native of Spain), on a 

 small scale, was tried in the gardens of Tynningham, the seat of the Earl of Haddington, 

 in 1789, but without success, although planted under a south wall, in a most sheltered 

 part of the garden. (J. M. in Gard. Mag.) The culture of this and other species is 

 practised to some extent in the neighbourhood of Alicant in Spain, and the details given 



