網頁圖片
PDF
ePub 版

Remarkable fact of an increase of Temperature, produced in water, by agitating it, discovered by Dr. J. Reade of Cork.

Phil. Jour. No. 87.. Dr. Reade put half a pint of water at the same heat as the atmosphere, which was 40°, into a tin bottle-shaped, vessel; into the aperture of which a thermometer was inserted, surrounded with chamois leather, and made to fit accurately, with its bulb nearly in the axis of the vessel. After briskly agitating it for a few minutes the thermometer rose 8 degrees; and continued to rise for some minutes even after the apparatus was uncovered and left at rest on the table. The tin vessel was afterwards enclosed in several folds of woollen cloth, and in three wet towels, and other precautions taken to prevent communication of heat from the hands, and on again shaking it the heat encreased as before.

The Rev. Mr. Hincks, lecturer on chemistry to the Cork Institution, repeated the experiment in a glass bottle, with the same result. By means of a thermometer placed between the bottle and the covering, he found its heat to be inferior to that of the contained fluid, and equal to that of the atmosphere, which proves that there could be no communication of heat from the hands, in the most satisfactory manner.

Experiments on the Liquid Sulphur of Lampadius, by Messrs. Vanquelin and Robiquet.

Ann. de Chem. T. 61. P. 146. Lampadius obtained this singular substance by the distillation of pyritous turf, and of pyrites mixed with a certain quantity of charcoal or sawdust. Messrs. Clement and Desormes employed sulphur and charcoal for the same purpose, but the process was very uncertain, not succeeding more than once in twenty times.

Messrs. Vanquelin and Robiquet obtained the liquid sulphur in three successive experiments from the same substances, and only used the precaution of cooling the flasks, adapted to the apparatus to avoid its volatilization

In their process they put finely pulverized charcoal in a dry state into a porcelain tube, to one end of which a small retort containing sulphur was adapted ; at the opposite extremity a long tube with a simple curvature was placed, which was then inserted into a flask three-fourths filled with wa, ter; a cavity was made in the part of the tube that entered the waterto serve as a tube of safety for the porcelain tube; this first flask, had three tubulures, to the second of which a straight tube was fixed, and to the third a bent tube communicating with a second fast surrounded by snow or pounded ice; to this last a tube was adapted crooked so as to fit it for collecting the gases. The porcelain tube was strongly heated in a reverbratory furnace, and when it was red hot the liquid sulphur came over of a citron yellow colour, having the appearance of an oil, and fell to the bottom of the water. If too much sulphur is passed over, a portion joins this oil and gives it more colour and density, the rest is condensed in the first glass tube, and becomes fixed the instant it touches the water. If the first fask is so near the furnace as to acquire the heat of 20°, or 250 of Reaumur, (80 to 90 Fahrenheit) the liquor sulphar boils and passes into the second flask, where the cold water completely condenses it. When the charcoal is heated alone, carbonated hydrogen mixed with carbonic acid is produced; when the sulphur first passes sulphuretted hydrogen is disengaged in great quantities; but as soon as the liquid sulphur begins to be formed, little or no gas is liberated.

Physical Properties. The liquid sulphur obtained first of a citron yellow colour, becomes quite colourless, very transparent, and of great fluidity on a new distillation, some sulphur remains behind in the rectifying vessel; its density is considerably more than that of distilled water; it has a very strong fetid, sulphureous, pungent, and garlic like smell: it has an exceeding sharp, pungent, and very cold taste; and is extremely inflammable.

Chemical Properties. When exposed to the air it speedily evaporates, without ļeaving any residue; when it is pure; if brought within a few inches of an ignited body it rapidly takes fire, yields a white flame, which laterally becomes purple, diffuses a suffocating smell of sulpliureous acid, and deposits sulphur in a yellow dust on every surrounding substance.

The 'water in which it has been received, assumes a milky appearance in a few hours, and has the property of precipitating the solution of lead of an orange colour, that of an oxigenated mercury white, and that of tin of a brick coloured yellow; it does not redden turnsole.

Concentrated sulphuric acid hias but little action on the liquid sulphur, laterally however, it dissolves a certain quantity of it, and acquires a tetid smell. Nitric acid seems to have more effect on it, when this mixture is managed so as to force a gas from it through lime water at a heat of 15° or 18° Reaumur, an elastic fluid is liberated, which does not disturb the line water, and which enflames with the same colour as oxide of carbon. The combustion takes place instantly and sulphureous acid is disengaged after a very pungent smell.

When placed in oxymuriatic acid gas it acquires a citron yellow colour; and if then exposed to the atmosphere it diffuses a very fetid arsenical like smoke in great abundance. It takes fire when brought near an ignited body; the gas when well washed also inflames, and diffuses a smell of sulphureous acid.

A mixture of nitric and sulphuric acids, has no effert on the lignid sulphur; some experiments seemed to shew that the weak acids had more action on it than the concentrated ones.

Pure caustic potash acts very feebly on liquid sulphur; after some time however it is coloured, and precipitates seviral metallic solutions in colours peculiar to this combination.

Ammonia seems to dissolve it a little more easily, it assumes a deep yellow colour, and also precipitates the metallic solutions.

Caustic Barytes dissolves it also in a great proportion, and assumes an orange colour; it precipitates the metallic solutions in the same manner.

Alcohol seems to dissolve it in any proportion, from the solution water precipitates sulphur, which unites in small globules, and falls to the botton of the liquid.

The experimenters think that nothing in these facts indicates the presence of carbon in liquid sulphur, but gives reason to suppose it is hydrogenated sulphur.

This singular substance may be of considerable nse in the arts; there is reason to suppose it would form a good solvent for varnishes, and even for caoutchouc affords considerable hopes. Perhaps also it may liave good ef, fects in medicine, and as an eudiometer.

On destroying Insects on Fruit-trecs. As the present season makes the subject of this paper interesting to many, it is hoped the information contained in it will be acceptable, which though not altogether new, yet is probably unknown to most of our readers.

Mr. Robert Hallet in the tenth volume of the Memoirs of the Bath Society has a paper on the use of tobacco water, for the destinction of insects, which he prepared in a cheaper manner than usual, and found extremely effectnal.

The effect of tobacco on insects has loug been known; in many shops fizmigating bellows are sold, for applying its smoke to destroy them on trees. But this method being attenderi with considerable expence, and the preparation of a wash for the trees, from an infusion of the leaf being no less costly, induced Mr. Hallet to try the effect of the liquor, procured by tobacco manilfacturers in pressing their tobacco, properly diluted with water,

In most large towns this liquor may be obtained very cheap, as there is no other use made of it at present, but to wash sheep for the scab, which consumes but very small proportion of it. A quarter of a pint of it will in general be strong enough to impregnate a gallon of water, and two gallons of it were sufficient

to

to prepare a wash for all Mr. Hallet's trees three times over, which are about fifty in number ; but no certain rule can be given for the mixture, since thé tobacconists will weaken the liquor as the demand for it increases. Mr. Hallet having used the diluted liquor with great effect for ten years past, near Axm.nster, his example followed by the neighbourhood, produced a great demand for the liquor, on wliich the tobacconists weakened it so much, that a pint of it was required to give the same effect to a gallon of water, that a wine glass full had often done before: but its strength may be known by the degree of colonr that it imparts to the water, which when strong enough will be tolerably brown.

Mr. Hallet's method of applying the diluted tobacco liquor, was by sprinkfing the trees all over with it with a brush such as plaisterers use in moisten. ing walls, and sometimes by pouring it on them from a watering pot with very small holes ; beginning at the top of the tree and laying it on very gently, to prevent waste; which would be very considerable, if it were done with violence or thrown from an engine. In one, two, or three weeks after, as found necessary, the sprinkling was repeated, and before the fruit got of sufficient size to be stained by the operation, was a third time perturmed, and this has been at all times sufficient to secure the trees from the depredations of the insects; to which the disease of trees that most gardeners consider as a blight, is entirely owing.

Every vegetable and shrub on which Mr. Hallet tried the preparation was com pletely freed from insects, and restored to health, though ever so much injured by them: and he thinks it might be applied to hop grounds, and in other large plantations with great efficacy. He freed his trees from the red spider, which was very troublesome a few summers ago, by watering them for ten successive evenings, very forcibly with an engine, and then sprinkling them while wet with the tobacco water.

At the end of this paper Mr. Hallet mentions that he has tried striped or rib. band grass with cattle, and found them very fond of it, and that they throve well on it; he states its produce to be very great, that it may be cut three or four times in the year, that it takes deep root, produces an early spring crop, is a good food for cattle in summer, but disappears in winter; it has lasted more than twenty years in his ground with undiminished produce: it spreads rapidly in' moist ground, soon fornis a thick mass of vegetation, and may be propagated either by seed or offsets.

Mr. Hallet also relates, that he has transplanted several large apple trees, which he bought from an orchard that was about to be converted to other purposes; they all succeeded, and many of them gave fruit enough to yield an hogshead of cyder the first season,

In many situations tobacco water cannot be procured; it is therefore useful to know other compositions which have the same effect; the following receipt taken from Crell's Chemical Annals, discovered by Mr. Catin, and which was found to be very effectual, may for this and other reasons be preferred to it.

Take of black soap of the best kind, one pound and three quarters, the same quantity of flower of sulphur, mushrooms two pounds, and sixty measures of river or rain water. Divide the water into two parts, in one of which the soap must be dissolved, and the mushrooms be added to it after they have been a little pounded. The sulphur tied up in a bag is to be boiled twenty minutes in the other half of the water; the water should be frequently stirred, and the sul. phur bag pressed, to make it communicate the necessary strength and colour to the water. When this liqnor is taken from the fire it should be well mixed with the other part, and should be stirred daily till it acquires a fetid smell. The more fetid it is the greater is its efficacy. The cask that contains the liquor should be stopped carefully after each stirring.

A little of this liquor sprinkled on plants or trees will entirely free them from insects. Mr. Hallet's method with the brush may be used for this purpose, or a syringe with an head an inch and half in diaineter, pierced with many small holes.

Caterpillars, beetles, earth-fleas, and tree-lice, will be destroyed by the first application of the liquid. Insects, which reside beneath the earth, as

was

wasps, hornets, and ants, require that the liquor should be poured over their nets gently (from a watering pot) for some time, that it may penetrate down to them. Ants nests, according to their size require from two to three measures of the liquid. Two ounces of nux vomica may be added to the mixture, and boiled along with the sulphur. This substance will be of great service, paru-, cularly when you wish to destroy ants nests. When the whole of the liquor has been used, the sedimeut should be buried, to prevent domestic animals from eating it.

It is very evident that tobacco water could not be procured in quantities more than sufficient for private gardens. It would be therefore desirable to have some preparations for hop grounds, large orchards, and other extensive concerns, that would answer the same purpose.. Some of the ingredients of Mr. Catin's composition may be procured in any quantity, but the mushrooms are seldom to be found; and the whole process of making it is too troublesome except on a small scale. It appears, however, from the efficacy of Mr. Catin's mixture increasing as it becomes more fetid, that the greatest part, if not the whole, of its effect is produced by the liver of sulphur, or sulphuret of alkali, formed in the liquor from the decomposition of the black soap by the sulphur. And this at least renders the efficacy of solution of liver of sulphur in destroying insects so extremely probable, that it may safely be recommended for that purpose. Its advantage over the other preparations mentioned is, that its materials cau be procured in any quantity almost in all situations, and that it is very cheap, and easily made.

Liver of sulphur may be made by the fusion of two parts of potash and one of sulphur; it may also be made by digesting two parts of pure caustic potash. and one part of sulphur in six times their weight of water, but this way would be too troublesome for the above use: but the best, and certainly the cheapest method of preparing it would be from lime : which may be done by heating powdered lime, with flowers of sulphur, till they melt or rather conglutinate together; or by throwing water on very fresh quicklime, covered with tlowers sulphur; or by boiling sulphur and lime in powder together in ten times their weight of water.

Solution of sulphuret of lime thus made may be had cheap enough to water crops of turnips, or other vegetables, in the field, in order to destroy the insects which prey on them, and which frequently destroy turnips altogether on their first appearance.

A vinous Liquor procured from the Prunings of Vines. Mr. Hall of this city has produced a vinous liquor, by infusing the prunings of vines cut small and bruised, in boiling water, in a mashing tub, in the same way as used for malt, and letting it ferment afierwards in proper vessels, The liquor thus made afforded a fine beverage, and on being distilled gave an excellent spirit of the nature of Brandy. When let to ran ou to the acetous fermentation it yielded uncommonly fine vinegar.

The prunings if dried in the shade. will at any time af erwards produce the same effect as the fresh prunings, if managed in the same manner. When intended for use an extract should be made from them with hot water, as in the common process for distilling from grain,

Mr. Hall also found that the leaves of the vine dried in the shade, formi an excellent substitute for tea on being infused in the same manner in a Lea-pot.

Of clearing fruit trees from Moss. Sprinkle, or dust, the limbs of mossy fruit trees when their leaves are off them, in damp foggy weather, or on a calm day, just after rain, with common woou ashes; and in the course of two or three months the moss will disappear wherever the wood ashes have touched, perhaps a large wooden dredging box would be the best instrument for this operation.

OBITUARY

[ocr errors][ocr errors]

OBITUARY OF DISTINGUISHED PERSONS.

Richard HURD, D. D. Bishop of Worcester. This learned and ingenious prelate, who for half a century stood prominent among the literary characters of the age, was the son of a respectable farmer at Congreve, a village in Staffordshire. He received his early education in part under Anthony Blackwall, author of the Sacred Classics, and master of the public school at Market iosworth; and being designed for holy orders, he was entered at a proper age; of Emanuel college, Cambridge, of which he became a fellow. He was afterwards presented by h's college to the living of Thurcasion, Leicestershire, in which retired situation he assiduously applied to those studies by which he rose to distinction. He first appeared, though anonymously, as an author in . 1749, in an edition of Horace's “ Ars Poetica,” with an English commentary and notes. This was reprinted in 1753, with Horace’s Epistle “ ad Augustum,” and two Dissertations, one “On the Provinces of the several Species of Dramatic Poetry;" the other,“ On Poetical Imitation.” They were dedicated to Dr. Warburton; and with more taste and elegance than that author possessed, displayed something of his spirit of overrefinement and strained explanation, though with abundant learning and ingenuity. In commenting upon Horace, he endeavours to mark out å plan and connected design in that poet, which many of his greatest admirers are unable to discover. He addressed also to Dr. Warburton in 1757 some anonymous “ Remarks on Humes Essay on the Natural History of Religioi," which that philosopher in his own Memoirs has stigmatised as being “ written with all the illiberal petulance, arrogance, and scurrility which distinguish the Warburtonián school;" and, indeed, whatever be thought of 'the reasoning, the manner too much justifies this censure. In 1758 he addressed to the poet Mason a “ Letter on the Marks of Imitation,” which is one of the most agreeable of his pieces of this class. It obtained for him the return of an Elegy inscribed to him by the poet, written in 1759, in which Mason ternis him the “ friend of his youth," and speaks of him as seated in “low Thurcaston's sequester'd bower, distant from Promotion's view."

Another publication in 1759 exhibited our author in a new light, and considerably added to his reputation. This was his “Moral and Political Dialogues," feigned to have passed between eminent persons of the past and present age, and, with an unnecessary licence of fiction, even said to be published from the original manuscripts. In the political part of this work he showed himself a sound constitutionalist and friend of civil liberty. His “ Letters on Chivalry and Romance,” printed in 1762, gave an ingenious deduction of the chivalrous principle from the nature of the feudal system, and other circumstances of the times, and displayed the author's research into the history of manners and society. They were republished along with the Moral and Political Dialogues, with the anthor's name, which had hitherto been omitted. Mr. Hurd's own merits, and the warm friendship of bishop Warburton, would not suffer him to remain in that sechsion from the world to which he had professed his attachment. The regard of that eminent prelate he had purchased not only by his dedication, but by an anonymous “ Essay on the Delicacy of Friendship,” in which he made some severe strictures on Drs. Jortin and Leland for their supposed disrespect to the object of his admiration. But, upon reflexion, he was so little satisfied with the warmth of zeal he liad displayed on this occasion, that he took great pains to suppress this pamphlet. Warburton, however, telt his obligations, and not only conferred upon him the archdeaconry of Gloucester, but gave him an opportunity of becoming known in the metropolis by associating him with himself as preacher at Lincolu's Inn chapel. In 1772 the first fruits of this appointment were given to the public by Dr. Hurd (he had now taken the degree of D. D.) in a volume of twelve sermons, preached at a Jecture founded by Dr. Warburton in the above chapel for the purpose of elucidating the prophecies in the Old and New Testament relative to the Christian Church. They were eutitled “ An Introduction to the Study of the Prophecies concerning the Christian Church, and in particular, concerning the Church of Papal Rome.” In these discourses the preacher displayed abundant

learning

[ocr errors][ocr errors][ocr errors][ocr errors][merged small][ocr errors][ocr errors][ocr errors][ocr errors][ocr errors]
« 上一頁繼續 »