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remedy to thofe who have not experienced it, but it never was found to do any injury to trees. It is to be done in February or March ; and if the wound gape very much, it may be filled up with cow-dung, which will defend the tree from 'injury till it heals. The digging about the root of the tree is a very good practice alfo on this occafion, and the cutting oft' the dead or withered branches.

-The grubs of beetles, called teredines and cofli, which get between the bark and the tree, do great mifchief : if the pla- ces can be found out where they lie, it is proper to pierce into the bark with a pointed inftrument upon them, and then to open a fmall hole below to iet out whatever moifture may be there. When trees of the fruit kind are burnt up and blifter'd on the bark with hot and dry feafons, and this is followed by a vaft number of the pucerons or tree-lice, which feed on the juices, fome recommend the boring a large hole in the main root, and pouring in fome brandy, then flopping up the hole with a pin of the fame wood. The tree fuffers nothing by this, but the juices are fp much altered for the prefent by it, that thefe animals do not like them, and confequently quit their habitation. Mortimers Husbandry, Esfc. p. 70. Seethe article Puceron.

If a tree is by any accident barked or {tripped all round, fo that it cannot grow any longer, the proper method is to cut it off juft above fome principal branch ; the flump muff, be cut off flanting and covered with clay, and the branch will foon become the body of a tree in the place of the other : the place _ where the flump is cut off being covered with a bark in the manner of a tree that is grafted.

Deer and hares, as alfo rabbits, are apt to bark tree's, and do them great mifchief. The defences again ft deer are by paling them round, or painting the lower part of the tree, but the firft is much the better method. The hares and rabbits may be kept off by tying bands of ftraw round the foot of every tree as far as they can reach. Evelyn recommends the rub- bing them over with human dung made into a foft parte with urine, fo that it may be laid on with a brum. ; but this is at- tended with great trouble, as it muff: be renewed after every hard rain. Some ufe tar and lime mixed together, but this always damages the tree more than thefe creatures would have done ; and in general ftraw-bands, where any thing is necef- fary, do be ft. Id. ibid. See Diseases of Plants, Cycl.

DISTENSION (Cyd.) — Distensio, Aiar<£»$, in the antient mufic, was ufed for the differences of founds with relation to acute and grave. Walih Append, ad Ptolein. Harm. p. 154. Nature in this refpeet, ftrictty (peaking, affigns no limits. But, with regard to our ufe, the antient muficians held, that the nature of what founded, and alfo of what was to judge, that is, the human ear, was to be confidered : for, neither the hu- man voice, nor even any inftrument, can give intervals or diftmfens immenfely great or fmall, nor could the ear judge of fuch. Ariftoxenes fixes the leaft interval or dijhnjion in practice, to the diefis enharmonica. As to the greateft, he thinks it does not exceed two octaves, and a fourth, or a fifth, if we confider any human voice ; or three octave;, if we con- sider one and the fame inftrument. He does not deny that the extent of the voice, confidered in differenr fubjects, as in men and children, may go even beyond four octaves. Ariftostm. p, 21. edit. Meibom,

DISTICHOUS Stalk, among botanifts. See the article Stalk.

DISTILLATION (Cycl.) — Combinatory Distillation, a term introduced into ufe by Dr. Shaw, in his Eflay on Di/iil/ation, to exprefs that fort of rectification of diftiUed fpirits which is done with additions, and which he other wife calls improper rectification, by way of diftinttion from that proper rectificati- on, which is only the method of reducing a fpirit to its utmoft degree of purity and perfection.

In the Combinatory Dijiillation many ingredients are added in order to rectify the fpirit, as the diftillers exprefs it ; and fome parts of thefe actually come over and mix themfelves along with the fpirit fo intimately, as not to be feparable again without great difficulty. This is done with a dehgn to alter, improve, or abolifh the natural flavour of the fpirit, but in- ftead of rectifying it, they only obfeure and pervert its true qualities. In the bufinefs of rectification, properly fo called, of the malt fpirit, all that is neceffary is the rediftilling the low wines procured from the wafh ; the again diftilling over the fpirit thus obtained, and called proof fpirit, into a totally in- flammable liquor called alcohol. This is done by the com- mon procefTes, only taking care not to increafe the fire by fudden fpurts, fo as to raife the oil with the fpirit, which if once mixed will not be eafily feparated again, and fcarce ever perfectly, whatever care is ufed. Shaw's EfTay on Diftillery. The methods of combinatory rectification, on the other hand, are very numerous, every diftiller having his peculiar noflrum about it. Malt fpirit is the general fubject of this procefs, and the means ufed to rectify it on this plan may be reduced to three heads: I. That by fixed alkaline falts alone. 2. That by fixed alkaline falts and acid fpirits. And, 3. That by faiine bodies and flavouring additions. The general method is that by fixed alcalrne falts alone; but it is furprifing to fee in how carelefs and flovenly a manner this is done by the generality of Suppl. Vol. I.

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our diftillers, though we are allowed to excel all other nations in it. The effect of this operation, when carefully performed, is to attenuate and thin the fpirit, and to keep lack a part of us grofs and foetid oil, and fo far to alter the part of the oil which comes over, as fcarce to leave the fpirit diftinguifhable for a malt fpirit.

This end is greatly promoted by a prudent and ffeady manage- ment of the fire, and by leaving out the faints ; but this is a thing our diftillers never attend to, they hurry over the ope- ration, working the ftill in its full force, and by this means raile and carry over the oil ; though the whole bufinefs of the procefs is to keep it back ; and they even fuffer the fulfome bitter oil, made into a kind of liquid foap with the fait in this pro- cefs, to run among the fpirit with the faints ; by this the whole intent of the procefs is fruftrated, and the fpirit ren- dered much harder to clean than it was before. This operation is ufually performed upon proof fpirit, -and the quantity allowed is from eight to fourteen pounds of fait of tartar, fixed nitre, pot-afh, or more commonly calcined tar- tar to the piece. The tartar being only roafted to a blacknefs in this laft procefs, is fold under the abfurd notion of a vinous fait, and the dealers will often praife the vinofity of their fpi- rit, becaufe diftiUed from this fait ; but the truth is, that this fait never fails to give, inftead of a vinofity, a faponaceous, urinous, or lixivial tafte and fmell. This is the great misfor- tune that attends the method of reflifying by means of fixed fait, for they all of them become volatile in part during the operation ; and this volatile portion partes over the helm with the fpirit, and impregnates it, uniting itfelf alfo with that por- tion of oil yet retained in the fpirit, and much more firmly combining it and the fpirit together than they were before ; fo that in reality the fpirit thus reflified is no other than an alkaline or tartarifed fpirit, as the chemifts call it; a thing ex- tremely different from a true vinous fpirit. This method therefore, though it were praflifed to the utmoft perfection, would never do what was intended by it, but would alter inftead of rectifying the fpirit. Hence there ap- pears the neceffity of fome acid to deaden the force of the al- kali thus ufed in the reflification. The neceffity of this gave occafion to the method of mixing acids and alkalies together for thefe purpofes. The acids ufed by our diftillers on this oc- cafion are thofe of the mineral kingdom by reafon of their cheapnefs, and the mod common in ufe among them are oil of vitriol, fpirit of nitre, oil of fulphur, and the like. The moft celebrated refiifiers in the malt way have got their repu- tation by the ufe of thefe acids. There is fome choice how- ever to be made of the fpirits according to the greater or leffer foulnefs and need of rectification, and they muft not only be well proportioned, but carefully introduced, and regularly mixed ; and indeed without fome ski/1 and judgment In the management of thefe corrofives, no diftiller ought to attempt to meddle with them.

Thefe ftrong and violent acids at beft are not fo well adapted to the work as the milder ones, particularly the fulphureous fpirit of vitriol, which comes over in the reaification of the oil ; to this may be added the common fpiritus nitri dulcis, and Mr. Boyle's acid fpirit of wine well prepared. Some of our rectifiers inftead of the fixed falts ufe quick-lime which cleanfes and dephlegmates confiderably : but this method requires the affiftance of acids alfo afterwards, to take oft" not only the alkaline difpofition, but alfo the ftinking flavour it leaves behind it. Some alfo ufe chalk, virgin earth calcined, and burnt animals bones. Thefe are of confiderable ufe in the rectifying brandy without rendering the fpirit any more unfit for the purpofe of the compounders than before, or requiring much acid afterwards.

The great art of tiling the flavouring ingredients in reaifica- tion is the proper admixture of falts in the operation, for without thefe the flavours added by this means do very little. ■The falts ufed on this occafion are either the fixed alkalies, as pot-afh and calcined tartar, or decrepitated common fait,' or calcined vitriol, alum, or fandiver. The flavouring ingredient is to be applied afterwards, and the whole quantity of die fpi- rit either drawn over again, or not, as the occafion and na- ture of the addition requires. But thefe faiine bodies perform fo very little, that the fpirit is ufually left impregnated with a flavour from its own oil, which is but badly hidden, or over- powered by the other ingredients. The moft common fla- voured, as they call them, are thefe, mace, orrice root, parf- nip, artichoak, rhodium, railin ftalks, damask rofes, wine lees, rape or grape husks, and the oil of wine. The laft of thefe is infinitely preferable to all the others, but is not fo well known. Thefe and the like ingredients judicioufty mixed, will when the fpirit is very well purified firft, give the flavour of foreign brandies with fome tolerable exaanefs ; but if this is not attained, their flavour will be loft in the original one and the genera! tafte refulting from the whole will be like nothing at all. The ultimate perfedion aimed at in all the proceffes of combinatory Dijiillation, is the depurating the Englifh malt fpi- rit at one operation, fo as to render it taftelefs and inodorous and yet vinous ; or elfe to make it referable the French brandy arrack, or fome other low -flavoured vinous fpirits.

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