up with new sound,, wood, which had incorporished qurich what little old woad remained, when I first taold stxin, bandA And again, w P. When, the wounds in the fruittrees are large as not to heal up in the course of a twelvertonta scho renew the composition annually, which que ita application inpigorates the trees, and seems to have the same effect them as a top dressing of dung has on land"boow 19110 q Mr. Knight remarking on Mr. Forsyth,saysama2 903 toʻJihad, however previously examined many trees, tot which Mr. Forsyth had applied his composition)ản Kens sington-gardens, and had observed that it had not, in\any que instance, produced the effects ascribed to it."ason sit si And, "the examination of the; fruit-treesomchis Ma jesty's gardens there, perfectly satisfied me of the total inutility of Mr. Forsyth's composition.30 to ytibios 9dT “ 1 Again, "I had invariably answered that I hadwatten+! tively examined the effect of Mr. Forsyth's domposition': when applied to trees of different species; unds that his: assertions respecting it were totally unfounded! 919dqeom Now, in these strong and pointed assertionsaladarwat but think Mr. Knight has gone too far; most people know that an exposure of wood to the effect of wind andį wet, or the general change of weather, facilitates itsisken: cay, and that a covering of paint, &c. retards and vpred vents it; at any rate it preserves the surface or exteriorą? and this being the case with wood cut and dried, there i cannot be a doubt but, that as Forsyth says, when wounds. in growing trees imbibe a large quantity of wet and mbistyre, it it causes a fermentation with the natural juices, which brings on disease and decay; and in time ¿destroys: the health and vegetation of the tree; and theseforglanly: covering that can be applied to defend such wounds: against these injuries, must operate casual preservativeķi and promote the health and natural growsin of the treebam It is well known that the wood of trees is formed by annual layers of sap, which first encircles the pith, and then by protruding itself between the bark, which proportionally expands, and the last year's layer or circle of wood, it gradually concretes or becomes wood: this is continued during the summer, and forms the periodical addition. Whenever a tree is wounded by a part of the bark being removed, or a limb or branch amputated, the sap pushes out all around the wound during the season of its flow, and annually extends itself, by sliding over the old surface until it meets, when, if not obstructed, it unites ; and afterwards the annual increase, or layer of wood is formed, in uninterrupted circles, the same as if no wound had been made. As the flow of sap over an exposed wound may be compared to that of melted tallow poured on a surface, it is obvious that a rugged surface must very much retard, if not wholly prevent, its advance. In this view Mr. Forsyth's practice of cutting away the obstructing dead wood in hollow trees will appear rational and proper; and when, by decay, the surface of a wound is sunk or hollowed, the extension of the sap is diverted, and prevented meeting and joining; and by its projecting above the wound and round, it forms a lodgment for the rain, and becomes in consequence a vehicle of putres faction, which extends itself through the tree. If those observations are correct, although we may not approve the idea of his composition operating as a stimulant, and producing the effects on a tree which a top dressing of dung does on land, or of effecting the incorporation of new wood with the old, we may give Mr. Forsyth the credit of a remedy in its application, for many injuries which Nature, when left to herself, is `in evitably evitably exposed to, particularly internal decays from external exposure; but, notwithstanding we admit the effic ciency of the composition in this respect, we may con sider it as too troublesome and complicated in its prepa ration, and tedious and filthy in its application, to obes come of extensive use; and adopting Hitt's recommenda tion, of applying soot to the diseased part of apricots, and observing its effects, it will readily occur that as soot, like charcoal, is a powerful antiseptic and a preventive of the ravages of insects, it might, when mixed with oil, and rubbed over a wound, prove also a preserv ative against putrefaction and the injuries of the weather. I have long since adopted this application, and found it completely efficacious; a quantity may at all times be readily collected and mixed up, so as to be laid on, like thick paint, with a brush, or rubbed over with a bit of cloth; and as very large wounds will require some years to enable the young wood to close over them, such parts should be covered or painted a second or a third time, at different periods, from six to twelve months, as the rain would otherwise find its way into the little clefts, occasioned by the contraction of the drying wood; and if drying oil, such as linseed, be used, it will prove more lasting and perfect in its effects. By these means, disease and rottenness will be prevented; the old wood will continue sound and hard, and the surface being preserved smooth, the new wood will form close upon the old wood, and consequently wounds thus treated will never prove so detrimental to timber as when they are left exposed. ふ It might be observed that the soot, thus applied, will adhere to the surface, and, in consequence, the new and old wood cannot unite or incorporate," but must remain perfectly separate and distinct from each other, without VOL. XXXV.-SECOND SERIES. Bbb union 1 union or adhesion," this, no doubt," will be the case; and, according to Mr. Knight, this has been explained by Dr. Anderson, as all the effect he believed to be produced by Mr. Forsyth's composition, and all that he or Mr. Forsyth meant to assert it had produced. A There are, no doubt, instances within the scope of every one's observation, of tall, straight, healthy stems growing upon or from old wounded and hollow stumps, without the aid of art; but whenever it is desired to encourage and support the growth of trees in this manner, it is, as Mr. Forsyth observes, more effectually done by reducing all the branches to one, and from time to time removing all other shoots growing from the old trunk, and also all decayed or rotten wood, and applying the covering recommended to the exposed and wounded parts, this, by excluding the air and moisture, will prevent decay and the waste of sap by putrefaction, and the future growth of the tree will consequently be better sustained. On the Use of Gypsum as a Manure, by Mr. T. SMITH, In a Letter addressed to the Earl of HARDWICKE. From the COMMUNICATIONS of the BOARD of AGRICULTURE. ZA Eastling, near Sittingbourn, SIR John Sinclair, in a letter to me in the summer of 1812, expressed a desire, that I would prepare a paper on the subject of gypsum, more particularly on the under-mentioned articles, in order to its being presented to the Board of Agriculture when they should re-assemble soon after the ensuing meeting of Parliament. But having been prevented by a severe accident, and a long con 1 10 tin ued tinued illness, from attempting to produce any matter that might be deemed, in any degree, useful or satisfac tory to the Board, yet, upon finding my health and strength of late much improved, I have taken the first opportunity of giving a brief reply to the particulars stated by Sir John Sinclair, trusting they may in some measure be acceptable to the Board, at least till I am enabled to prepare a more ample detail of the various striking cir ́cumstances that have contributed to render the use of gypsum so general throughout the county of Kent, and which I hope to accomplish to the satisfaction of the Board, at no great distance of time. The particulars required to be answered, were; 1st, The advantages of gypsum as a manure;-2d, To explain the soils and crops for which it is best calculated; 2 3d, As to the best mode of application, time, and quantity per acre implied;—and, 4th, To state some account of the causes of its failure, which has frequently taken place. 1st, Advantages of Gypsum.-The advantages arise from growing upon land exhausted by tillage, and requiring rest, seeds laid down with sainfoin or lucern, producing from two to three tons per acre of hay, when the soil, without such aid, would not produce one ton per acre; and if gypsum be sown upon clover designed to be ploughed up for wheat, that crop is generally found benefited in the proportion of three and a half, or three to four the excess; and I once experienced in a field of seventeen acres, that had been gypsumed when clover, the excess as high as four and a half to three, throughout the crop. 2d, Soils and Crops for which it is best calculated,-All soils almost that are naturally dry, such as light or stiff loams, with a mixture of flints or gravel, sandy land in |