THE GARDENER'S MAGAZINE, JANUARY, 1827. PART I. ORIGINAL CORRESPONDENCE. ART. I. On the Employment of Salt as a Manure in Gardening. By Mr. G. W. JOHNSON, of Great Totham, Essex. Sir, AS horticulture requires that its professors should be men of science, and consequently of expanded minds; as it is patronised and practised by the fairest, the wealthiest, and the most talented inhabitants of every well civilised country, it may be justly expected to take the lead of its sister art agriculture, in all that relates to the cultivation of the soil, since the practitioners of the latter are in general much behind those of the former in every thing but mere empirical knowledge. In most cases this expectation is fully justified. The examination of the value of salt as a manure is an exception, and rather a remarkable one. Its employment, recommended on strictly scientific principles is slowly overcoming the prejudices of the agriculturist, whilst nothing like a general application of it to the crops of the garden has been known to have been attempted by any, even of its most enlightened advocates; it certainly is not commonly esteemed as one of the gardener's sources of fertility. In calling your attention to the subject, I shall merely throw together some ideas and facts which have lately occurred, referring you, sir, and those who wish to enter into the examination of the subject more in detail, to my brother's essay on its employment in agriculture, &c. (Encyclopædia of Agriculture, p. 1170, A. D. 1820.*) That An Essay on the uses of Salt for Agricultural Purposes, with Instructions for its Employment as a Manure, and in the Feeding of Cattle, &c. By Cuthbert William Johnson, London. 8vo. 1820. the employment of salt as a manure is not a modern recommendation is proved unequivocally by the 34th and 35th verses of the 14th chapter of St. Luke's gospel: and of perhaps all the writers upon rural subjects through succeeding ages, not one has escaped to us but mentions salt as a fertilizer of the ground, or as useful in some form or other to our crops. Lord Bacon recommends it generally for the garden. Sir Hugh Platt eulogises it for grass platts, and it is certain no application tends more to keep their verdure permanent, or to divest them of worms. Moses Cook, gardener to the Earl of Essex, in 1679, says that salt to seed "is as sack to a young child, a little doth a great deal of good." Switzer recommends it for grass and for gravel walks; " I would have those," says Cook before mentioned, "that lay salt on their gravel walks to kill their weeds, observe if in a few years they do not produce more weeds than some other that had not salt laid on them at all." Those who apply salt for this purpose, as recommended also lately by Mr. Sinclair, author of the invaluable Hortus Gramineus Woburnensis, must repeat the application at least every other year; if the salt is not in excess it promotes the growth of the weeds. Salt is a destroyer of moss on fruit trees, as long as it is present in abundance, but if not applied every other year the moss grows more luxuriant than ever. Hitt recommends it for fruit trees. About Alresford in Hants it is generally applied to onions. Mr. Knight recommends its use to late crops of peas. Mr. G. Sinclair recommends it for carrots. W. Horne, Esq. and others eulogise its employment upon turnip lands. The Rev. E. Cartwright, and others, have experienced its benefits upon potatoes; and were I to name every individual who bears testimony to the same effect upon the above mentioned and other crops, and to detail only the results of their experiments, I should trespass by far too much upon your pages. In the absence of all experiment, there are some plants under the gardener's immediate care, which, from a knowledge of their habitats, we might feel convinced would be benefited by the application of salt. The beet is a native of the sea-shore, as is the sea kale and samphire: now all these plants have been found benefited by the application of salt when growing in our garden quarters. Lord Bacon especially recommends it to beet; and in a communication I have just received from Sir T. D. Acland, Bart., of Killerton Park near Exeter, his farmer advocates its use for mangel wurzel, which is a member of the same botanical family. The cocoa nut tree is said only to flourish in the vicinity of the sea, which may afford a hint to the protectors of this and others of the palms in our hot-houses to assist them by the application of salt. The fact which has often been noticed, and satisfactorily explained, that brocoli and other members of the brassica tribe growing on soils manured with salt, endure the rigour of winters which destroy others growing upon unsalted ground, may also serve as a memento to the curator of every hot-house to try its protecting powers upon some of the tenderest of its tenants. The benefit of salt when applied to flowers is unequivocal; even those separated from their parent stems and placed in `vases are preserved longer in vigour by having a few grains of this saline stimulant dissolved in the water. The late T. Andrews, Esq. of Coggeshall informed me, that tulip seedlings sooner acquired their perfect colour if the beds were manured with salt, than those in similar beds untreated with this manure. The benefit arising to bulbous-rooted flowers, &c. from its use is farther confirmed by the following communication lately received by my brother from Mr. Hogg, florist, Paddington:- "From the few experiments that I have tried with salt as a manure, I am fully prepared to bear testimony to its usefulness. I am satisfied that no hyacinths will grow well at a distance from the sea without it. I am also of opinion that the numerous bulbous tribe of Amaryllises, especially those from the Cape of Good Hope, Ixias, Alliums, &c. &c. should have either salt or sea sand in the mould used for them. I invariably use salt as an ingredient in my compost for carnations, and I believe I may say, without boasting, that few excel me in blooming that flower." In concluding these irregular observations, the chief object of which is to call the attention of gardeners more generally to the subject, I shall only pause a minute to deprecate illjudged experiments and hasty conclusions. Let the same patient resolution in the pursuit and desire for the illustration of truth be found as is exhibited in the table of experiments by Mr. G. Sinclair, given in my brother's essay; let them not conclude, with a friend of mine, that salt is destructive to plants, at all events, to potatoes, because not a single set vegetated in those rows where he filled the holes made by the dibble with salt after putting in the potatoe! but let them at least be guided by the directions of those who have had some experience in the research; let them investigate without prejudice, and they may perhaps agree in repeating the enthusiastic declaration of Mr. Cline, of medical celebrity, "salt is of as much benefit to land as to the human constitution." If you consider the above would at all tend to call the attention of gardeners to that which I am convinced is one of their best friends, if inserted in your Magazine, (the best demonstration of my approval of which is my constant perusal of it as it appears,) I shall be very happy at a future period to communicate such facts, &c. as may occur. Great Totham, Essex, I am, Sir, &c. G. W. JOHNSON. The following is a subsequent communication from Mr. Johnson on the same subject. We are sorry that he should imagine, that because we consider salt as a stimulus, we are therefore unfavourable to its use in agriculture or gardening. If this conclusion were to be drawn, we should be also unfavourable to the use of lime, which, in common with agricultural chemists, we consider more as a stimulant, and decomposer of food already in the soil than as food itself. We are not, however, on that account, the less an advocate for the employment both of salt and lime. See Encyc. of Agr. § 2213. Cond. et seq. Sir, I REGRET most sincerely to find, by the observation contained in p. 402. of the last number of the Gardener's Magazine, that you are far from being favourably inclined to the employment of salt as a fertilizing medium. I am almost inclined to agree with you in considering salt as beneficial to plants by stimulating them, and other proximate effects, rather than as being their actual food, but there are some considerations and facts, which being opposed to it, I am unable satisfactorily to explain away. Water, wherever it is obtained, is always found to contain common salt, even rain and distilled water are not perfectly free from it; such waters as are derived from near the surface of the earth always contain the most. Now, as such water is one of the chief sources of nourishment to plants, are we not justified in concluding that the salt is taken up with the water?-At all events, many upland plants, as the Gratiola officinalis, Mesembryanthemum crystallinum, &c. (Thomson's Chem. ed. 6th. v. 4. p. 244, 245.), contain it in a very notable proportion. Mr. G. Sinclair states from experiment, that wheat grown upon a soil salted, indicated, on analysis, nearly double the quantity of alkaline muriate than similar grain grown upon a similar soil that had had no salt applied. We must not either imagine, that plants absorb the salt of necessity, it being presented to them in solution, for Saussure has demonstrated by experiment that plants have the power of selecting salts from their solutions; acetate of lime and common salt being dissolved in the same water, some plants of Polygonum Persicaria, &c., absorbed a considerable portion of the latter salt, but rejected the former entirely. (Saussure's Recherches, p. 247-61.) I never tested with nitrate of silver the infusion of any plant that did not indicate the presence of an alkaline muriate. Such being the fact, I am not aware of any reason that should forbid us considering common salt as an essential constituent of some plants; if we allow that it is such of the blood and other parts of animals, and if it is an essential constituent, they must derive it from their food. Sir H. Davy, in his Agricultural Chemistry, (2d ed. p. 337,) says, "when common salt acts as a manure, it is probably by entering into the composition of the plant in the same manner as gypsum, phosphate of lime, &c." We could hardly attribute the benefits arising from these to plants to their stimulating qualities. I offer these observations, Sir, not in the belief that they are new to you, but in the hope that they may induce you to a more full examination of the evidence for and against the employment of salt as a manure, an examination which I am sure could not fail of securing you to it as a friend, which I am the more anxious you should, being an advocate for it myself, as you stand in your editorial capacity as one of the beacons of horticulture. I am, Sir, yours, &c., G. W. JOHNSON. We shall not argue with Mr. Johnson or Mr. Collyns, (Gard. Mag. p. 401.) as to whether salt be a stimulus or a manure, but rather strongly recommend the able communication of the former to the practical reader, and await the light which may be thrown on the subject in a future number by the latter correspondent. Used in small quantities, we are very much inclined to think with Mr. Cline, that salt may be found" of as much benefit to land as to the human constitution." It does not follow, that because it is used in large quantities to destroy, it may not be used in small quantities to promote, vegetation. We lately saw an approach road in Staffordshire, thickly coated over with salt, the article being in that part of the country abundant and cheap; we hope, therefore, that some of our readers in that quarter will try some experiments, and communicate the result. Suppose we |