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separated into pairs by some conducting sub- cartridge paper, and silver leaf. The silver leaf stance that does not interfere with their electro- is first laid on paper, so as to form silvered motive powers. To ascertain if a liquid was paper, which is afterwards cut into small round essential to this effect, he mounted a pile with plates by means of a hollow punch. In the pieces of cloth not moistened, and he found the same way an equal number of plates are cut electric effects were still produced, but somewhat from thin flatted zinc, and from cominon writing weaker than with the wetted cloth. He then in or cartridge paper. These plates are then arstituted a series of experiments, successively ranged in the order of zinc, paper, silvered paper mounting the pile with different animal and ve- with the silvered side upwards; zinc upon this getable substances, interposed between the pairs silver, then paper, and again silvered paper,

with of metal, instead of wetted cloth. Of the various the silver side upwards; and so on, the silver substances tried, he preferred writing paper, as being in contact with zinc throughout, and the most convenient of those that were efficient. each pair of zinc and silver plates separated by The apparatus constructed in this way was found two dises of paper from the next pair

. An exto have the same electrical indications as the tensive arrangement of this kind inay be placed cominon Voltaic pile, but it produced no che- between three thin glass rods, covered with sealmical effects, however numerous the pairs of ing-wax, and secured in a triangle, by being ceplates; nor was any oxidation of the zinc pro- mented at each end into three equi-distant holes duced by its most protracted action. These cir- in a round piece of wood; or the plates may be cumstances led to the idea, that, by the extension introduced into a glass tube previously well dried, of the number of groups, a kind of perpetual and having its ends covered with sealing-wax, electric machine might be formed; and, as in and capped with brass; one of the brass caps the previous trials, it had been found that the may be cemented on before the plates are introeffect was rather increased by pasting the paper duced into the tube, and the other afterwards ; upon the silver or copper. Dutch gilt paper, each cap should have a screw pass through its which consists of thin copper leaf, laid upon centre, which terminates in a hook outside. This paper, was employed instead of the nsual silver, screw serves to press the plates closer together, or copper plates, and moist conductors : 800 and to secure a perfect metallic contact with the plates of tinned iron being put together with the extremities of the column. To fill the tube with Eame number of Dutch gilt paper between them, discs, it is necessary to employ a cylindrical the copper sides being all turned in one direc- rammer of baked wood with flat ends, and when tion, the combination was found to affect the a small number (as about half a dozen discs) are electrometer more powerfully than any Voltaic introduced, they should be thrust down, taking battery had been ever observed to do; but on care to ensure their perfect contact; and the the application of the usual glass tube with operation of the apparatus will be ensured. water, no chemical effect was noticed. The ap 124. Soon after the invention of the column, paratus was left for a considerable time, and its Mr. B. M. Forster discovered that, when a sushiaction on the electrometer continued without ciently extensive series was put together, its elecdirninution; and subsequent experience has tric power was sufficient to produce a sort of shown that it does so for any period during chime by the motion of a small brass ball bewhich the experiment has been continued. Thus tween two bells, insulated, and connected with was invented a new and important Voltaic ar- the opposite extremities of the column. He rangement, highly valuable both in a theoretical constructed a series of £500 groups, and by its and practical view: in the former, as separating agency kept a little bell-ringing apparatus in the pure electrical effects of the Voltaic battery constant activity for a considerable length of from its chemical power, and demonstrating the time. permanence of its electro-motive faculty: in the 125. Mr. Singer contrived an arrangement which latter

, as providing a spontaneous and perma- is well calculated to form a perpetual motion, Dent electrical machine, in which the opposite by excluding, to a very considerable extent, the electrical states perpetually exist, without any operation of extraneous causes of interruption, new excitement. Besides these properties, the and it at the same time renders the disposition new apparatus promises to become an important of the apparatus rather elegant. A series of from meteorological instrument; for the degrees of its 1200 to 1600 groups are arranged in two columns electrical indications have been observed to vary of equal length, which are separately insulated with the different seasons of the year, and are in a vertical position by glass pillars constructed probably influenced by some of the causes by on his principle of insulation; the positive end which our atmospherical phenomena are pro- of one column is placed lowest, and the nega

tive end of the other; and, their upper extremities 122. To distinguish this instrument from the being connected by a wire, they may be consiusual Voltaic apparatus, from which it differs dered as one continuous column. A small bell in many respects, M. De Luc proposed to call is situated between each extremity of the coit 'the Electric Column,' an appellation suffi- lumn, and its insulating support, and a brass ciently appropriate, since the effects it produces ball is suspended by a thin thread of raw silk, are purely electrical.

so as to hang midway between the bells, and at 123. Mr. Singer made very numerous expe- a very small distance from each of them. For riments, on the constructions of such columns, this purpose the bells are connected, during the and varied their combinations most extensively. adjustment of the pendulum, by a wire, that their The materials he preferred, are thin plates of attraction may not interfere with it; and, when flatted zinc alternated with writing or smooth this wire is removed, the motion of the pendu

duced.

lumn commences. The whole apparatus is placed column, it discharges its electricity by striking upon a circular mahogany base, in which a against the cross silver wire. groove is turned to receive the lower edge 129. There appears every reason to believe, of a glass shade with which the whole is co that the action of a well-constructed column vered.

would be permanent. There is, however, a pre126. If a column of about 1000 series is placed caution necessary to their constant and immehorizontally, with each of its extremities resting on diate action; the two ends of a column should a gold leafelectrometer, the electrometers will each never be connected by a conducting substance diverge; that connected with the zinc extremity for any length of time; for if, after such conof the column will be positive, that connected tinued communication, it be applied to an elecwith the silver extremity will be negative. If trometer, it will scarcely affect it for some time. the column be very powerful, the gold leaves of It is, therefore, necessary, when a column is laid the electrometer will alternately strike the sides by, that it be placed upon two sticks of sealingof the glass, hut this motion is soon stopped by wax so as to keep its brass caps at the distance their adhering to it. If the simple divergence of about half an inch from the table, or other only is produced, on touching either extremity conducting surface on which it is laid. And if of the column, the electrometer connected with a column, which appears to have lost its action it closes, and that at the opposite extremity has by laying hy, be insulated in this way for a few its divergence increased. This is analogous to days, it will usually recover its full power. the effect of the Voltaic battery when disposed 130. There is another cause of deterioration in a similar manner; but the motion in the co- which is more fatal; it is the presence of too lumn is slower, which arises from the more im- much moisture. If the paper be perfectly dry it perfect conductors of which it is composed. is a non-conductor, and will not therefore pro

127. There is some cause, not yet perfectly duce any action in the column; but this perfect developed, that appears to influence the power dryness can only be obtained by exposing the of the column to produce the motion of light paper to a heat nearly sufficient to scorch it

, and metallic pendula. In the bell-ringing apparatus, in its dryest natural state the paper will be found for instance, though the motion always continues, sufficiently a conductor, even when, hy exposing it is much more rapid at one period than another, the paper discs to the heat of the sun, they have and the oscillations of the pendulum, though been so dried as to warp considerably. When usually as uniform as that produced by mecha- the paper is sufficiently dry, the action of the nism, is on some occasions singularly wild and column continues without diminution; and on irregular. The frequency with which the gold taking such an apparatus to pieces after it had leaves of an electrometer strike the sides of the been constructed thirty months, no trace of oxiglass, when connected with an electric column, dation was evident on the zinc plates. is also different at different times; the variations 131. The size of the plates in the column need observed in some experiments of M. De Luc not be large; Mr. Singer has constructed them are much more considerable than we have yet of various sizes, and finds no proportionate adnoticed, with the more powerful columns of Mr. vantage by extending the diameter beyond fiveSinger's construction.

eighths of an inch; they may even be constructed 128. De Luc proposed, as an interesting ob- much smaller, and yet found to act with the ject of enquiry, to make regular observations on greatest precision. the action of the column, and the number of os 132. By connecting the extremities of a column cillations it would produce in a given time, at of at least 1000 series, with the opposite coatings each observation. For this purpose a single of a Leyden jar, during a period of from one to column of from 1000 to 2000 series may be five minutes, a charge is usually communicated supported vertically on an insulating pillar. to it capable of affording a small but distinct bent wire, with a ball at its lower end, is to be spark, when the discharge is made by a wire that connected with the upper extremity of the is not very thick. column, so as to hang parallel with, and at some 133. Mr. Singer observes that the most extendistance from it; the ball at its lower extremity sive series he had ever made experiments with, being diametrically opposite to a similar ball consisted of 20,000 groups of silver, zinc, and that is screwed into the lower cap of the column. double discs of writing paper. Its power was To the same cap there is also screwed a brass considerable. Pith-ball electrometers, with balls fork with a fine silver wire stretched between its of one-fifth of an inch diameter, and threads of extremities; this is placed above the ball and four inches long, diverged to the distance of two projects farther from the column, so that when inches and upwards, when connected with its the pendulum moves towards the ball it strikes opposite extremities. An electrometer in the this wire first, and receives a kind of jerk, which centre was not affected. When either extremity prevents it from sticking. The pendulum con- of the column was connected with the ground, sists of a gilt pith-ball suspended by a very fine the electrometer attached to that extremity closed, silver wire, which hangs parallel to the bent and the central electrometer opened with the biass wire, to which it is fastened at top; the same electricity, whilst that connected with the arrangement is such, that the gilt pith-ball would opposite extremity had its original divergence be always in contact with the brass ball that pro- considerably increased; but the electro-motion ceeds from the upper extremity of the column, was so slow, that some minutes were required to if the apparatus had no electrical power; it produce the full effect. therefore always returns to this situation, when, 134. By connecting one extremity of the series after being attracted to the lower extremity of the with a fine iron wire, and bringing the end of

tace.

this near the other extremity, a slight layer of which no gas whatever appeared. It was obvarnisto being interposed, a series of minute served that, when this metallic conductor was bright sparks were obtained by drawing the point removed, the appearance of the gas was not imof the iron wire lightly over the varnished sur-mediate, since there was an interval of about

two seconds between the removal of the wire 135. A jar containing fifty square inches of and the appearance of bubbles. After the ciated surface was charged by ten minutes con- process had continued two hours and a half, a tact with the column, so as to convey a disagree- bulk of gas was produced equal to two-thirds of able shock, felt distinctly in the elbows and a cubic inch. This gas was mixed with an equal shoulders, and by soine individuals across the bulk of common air, and exploded on the applibreast.

cation of a lighted taper. 136. The charge from this jar could perforate 141. These ingenious experimenters, supposing thick drawing paper, but not a card. It had just the phenomena in question to arise from the depower to fuse one inch of platina wire, of the composition of the water, thought it surprising sath of an inch diameter.

that the hydrogen should make its appearance 137. Notwithstanding the considerable electric at a distance of an inch and three-quarters from power of this combination, it had not the slight- the point where the oxygen was disposed of. est chemical action; neither the best nor worst 142. They then made the same experiment conducting media were affected. Saline com with a tube thirty-six inches in length, but no pounds, tinged with the most delicate vegetable gas was observed. When they introduced an colors, were exposed under the most favorable infusion of litmus instead of pure water, they circumstances to its action, and in some instances observed that the fuid in the vicinity of the wire for many days, but no chemical effect was pro- connected with the zinc end of the pile became duced.

red, and hence were led to suppose that an acid 138. It therefore appears indispensably neces- had been produced. The fluid at the other sary to the chemical power of the Voltaic appa- wire was not changed, but gas, as usual, was ratus, that a liquid be interposed between each evolved. pair of its plates, whilst, for the pure electrical 143. It may be proper to state that, in every effects

, the only condition appears to be the apparatus constructed for practical purposes, asociation of the two metals, and the connexion there is a combination of three different subof the different pairs, by some conductor that stances in contact with each other, in successive does not interfere with their electro-motive groups; in general it is an arrangement of copper, power.

zinc, and some conducting fluid. It is demon138*. The first experiments made upon the strable that the primary source of the electrical most pile in this country appear to have been power of the apparatus is the association of the performed by Messrs. Nicholson and Carlisle. two metals; and, according to Volta, the interAfter observing the effects then ascribed to the posed fuid serves only as a conductor of the piles on bringing the wires from each end of the effect of one pair of metals to another. As far column in contact with a drop of water, they as electricity is concerned, this opinion appears observed a disengagement of bubbles of some to be correct, for the electrometer is acted on, elastic fluid.

whatever be the nature of the interposed fluid, 139. On closer examination they found the and the degree of divergence is proportioned to gas to be hydrogen. They then took a glass the number of the plates. The electrometrical tube, about half an inch in diameter, into each effects prove also, that, the arrangement of a End of which a cork was inserted, the tube series of zinc and copper plates, with an interbeing filled with water. Through each cork was posed fluid, forms a conducting column, which, introduced a brass wire, so that the ends of the in its insulated state, is positive at one exwires in the glass were about an inch and three- tremity, negative at the other, and neutral in the quarters of an inch. The pile employed con- middle. This may be easily shown by three sisted of thirty-six half-crowns, and as many gold-leaf electrometers, connected at the same similar pieces of zinc, and wet pasteboard. The time with an apparatus of 300 or 400 pairs of zinc end of the pile was then connected with plates. The electrometer, connected with the One of the wires in the tube, and the silver end copper extremity, will diverge with negative with the other, so that the circuit formed by the electricity; that connected with the zinc end pile was separated by the water in the tube will separate to the same distance positively; placed between them. A stream of bubbles was while that connected with the central plate of observed at the end of the wire, in the tube the series will not be affected. But, if either connected with the silver end of the pile. No extremity of the battery be connected with the as was disengaged from the opposite wire, but ground by means of a wire, the leaves of the speedily became tarnished, first of an orange electrometer connected with it will close ; and color

, and ultimately black. The tube was then those of the central electrometer will open with reversed, when it was observed that the wire, the same electricity, and to the same extent, which in the first experiment became tarnished, whilst those of the opposite extremity will have eave out bubbles, while that which had before their original divergence increased. given out gas, in its turn became tarnished. 144. Hence it appears that there is a real

140. The einission of gas from the wire con- electro-motive property in the apparatus, by Dected with the silver end of the pile was con which the zinc end constantly tends to become stant and uniform, except when a metallic circuit positive, and the copper end negative; and it is kas formed between the ends of the pile, during also obvious, that the extent of this operation, Vol. VIII.

н

at either extremity, is increased by connecting the nature of the interposed fluid. If these the opposite end with the ground. This last effects then, are produced by electricity, they experiment, by which the central plate may be can only result from its circulation in the aprendered either positive, negative, or neutral, at paratus; and, as there is no reason to suppose pleasure, proves also that the interposed fluid that the electro-motive power of the associated never acts as an insulator, for if it did so these metals ceases when there is a conducting comchanges could not possibly occur.

munication between their opposite surfaces, but 145. As the contact of either surface of the rather that it is accelerated by such a circumbattery with the ground increases the electrical stance; that very acceleration may be the cause state of the opposite extremity, the same cir- of the phenomena, and the effects observed corcumstance may be presumed to take place with respond very nearly with such an idea; for, if it every pair of associated metals, when their sur- be admitted that the connexion of the opposite faces are in contact with a conducting fluid. ends of the Voltaic battery by a conductor, occaWhilst the apparatus is insulated, the first zinc sions a current of electricity from the positiva plate can only act on the electricity of its asso to the negative, that current must be more rapid, ciate, the first copper plate ; but the second zinc in proportion as the conductor is more perfect. plate, through the conducting interposed Auid, Now it is found that the chemical effects are can act on both these, besides its companion, the most considerable, and more promptly produced copper, and may therefore become more highly in fluids of the highest conducting power; thus positive; and it is easy to conceive that such a , the quantity of gas liberated in a given time from repetition of action would be attended with an common water, is greater than from distilled increase of effect, proportioned to the number water; saline fuids furnish more than common of plates; and that the electrical tension of water; solutions of alkali more than saline fluids, either end must be increased by connecting the and acids more than alkalies : and, as the effects other with the ground.

of a simple combination are influenced by the 146. To ascertain if this principle really ope- same causes as those that operate with a series, rated with a single combination, Nr. Singer took the fluids that are susceptible of the most rapid a pair of circular plates six inches diameter, decomposition are also most active in exciting very clean and smooth, one being formed of the chemical effects of the battery, when enzinc and the other of copper, and each provided ployed as the connecting medium between its with an insulating handle. When both plates plates. were held by their insulating handles, and the 148. Acids are of all other fluid bodies, exzinc was successively applied to the flat surface cepting metals, the most perfect conductors, and of the copper, and after each contact made to the chemical effect of the battery is more touch the insulated plate of a condenser of six powerfully excited by them than by any other subinches diameter; twenty contacts were required stances; it is possible that their chemical action to communicate such a charge to the condenser on the zinc may have some share in modifying as would occasion the leaves of a very delicate the quantity of electricity, or the rapidity of its electrometer to separate to a quarter of an inch. motion; but it is certain that the effects are not But when the copper plate, instead of being in proportion to the chemical action; sulphuric held by its insulating handle, was simply laid on acid, for instance, acts as powerfully on the zinc the hand, or on any similar conducting body, as nitric or muriatic acid, but it is not so active ten successive contacts of the insulated zinc in producing the chemical agency of the battery: plate, communicated a charge to the condenser, in like manner the alkalies, which exert a very which occasioned the gold leaves to separate to trifling action on the battery, excite its powers the distance of more than half an inch. On re- with greater energy than many saline fuids peating these experiments, with the variation of which are more efficient as chemical agents. touching the condenser with the copper plate, 149. The ignition of wire, and of charcoal in held by its insulating handle, and brought in the Voltaic circuit, is conformable to this view; contact with the zinc plate, tirst insulated, and these substances are the most perfect conductors then uninsulated, similar results were obtained, known, and, when made the medium of commubut with the contrary electrical state. Hence nication between the opposite ends of a battery, the similarity of action in a single pair of metals, must accelerate its electro-motive power to the and a combined series, is sufficiently proved; greatest extent. The rapid circulation of elecand the preceding statement of the manner in tricity, thus obtained, produces ignition, if the which the electrical power is supposed to in- conductor be not too large in proportion to the crease with the number of associated plates, is quantity of electricity ; but, within this limit, the rendered highly probable.

effect will be greatest with the thickest wire, 147. So far the phenomena are sufficiently because the acceleration will be more considersimple and consistent, for those described are able in proportion to the facility of transmission. not materially influenced by the nature of the There is, perhaps, no other view on which the interposed fuid, nor do they occur, but when continued ignition of wire, and the increased the extremities of the apparatus are unconnected action of large plates is so intelligible. with each other, and consequently capable of 150. The cessation of chemical agency, and maintaining the opposite electrical states. But igniting power, as the chemical action of the the chemical effects, the shock, and the power acids or other menstrua declines, may arise fronu of ignition, take place only when the extre- the total change which then occurs in the nature inities of the apparatus are connected by some of those fluids ; their conducting power is much conductor, and are also materially influenced by diminished, and they may possibly, by the change

in their chemical properties, acquire some faculty in the same way. It is fluid at the temperature of electro-motion subversive of the effect of the of 200°, and passes into vapor at a strong red combined metals.

heat. At common temperatures it is a soft metal, 151. The extensive experiments of Messrs. and a globule of it may be easily spread into a Hisinger and Berzelius, confirmed by the re- thin leaf by the action of a knife. It decomposes searches of Sir H. Davy, had demonstrated the water violently, and floats on its surface, but constant separation of oxygen, and compounds in does not inflame; the water is rendered alkaline, which it prevailed, at the wire proceeding from the and, when examined, is found to contain pure zinc surface, and of hydrogen and other inflam- soda. It acts nearly in the same manner as mable matter, at that connected with the copper potassium, but with less energy, on most subsurface; and, at this latter, alkali was also fre- stances, and must consequently be preserved quently found, and, from analogy, it was in con- under naphtha. When thrown on the surface of sequence concluded, that the alkalies probably nitric acid it inflames, and burns with great brilcontained a considerable proportion of some liance; it also occasionally scintillates when inflammable substance.

thrown upon hot water. The proportion of oxy152. This conjecture was confirmed by Sir H. gen with which it combines to form soda, may be Davy in 1807: he found that a thin piece of potassa learnt by noting the quantity of hydrogen evolved or soda, slightly moistened by exposure to the air, from water by a given weight of the sodium. and placed between two conductors of platina, pro 155. Both these new metallic substances unite ceeding from the opposite sides of a powerful Vol- with mercury in various proportions, and form taie apparatus, was resolved into a peculiar metal- amalgams which decompose water, but more lie substance highly inflammable, which appeared slowly than the metals themselves; these amalat the negative surface; and oxygen gas, which gams act upon all other metals, even platina and was evolved at the positive surface. By an ex- mercury. tensive series of experiments, it was shown that 156. The decomposition of the alkalies may, these bodies are, in reality, metallic oxides, and by care and attention, be effected with a battery that the proportion of their constituent parts is of fifty pairs of plates of three or four inches somewhat different, being in round numbers, for square; but the results are rather uncertain : 200 potassa six parts of metallic base to one part of plates form a very efficient arrangement; they civgen, nearly; or it may be stated that potassa should be excited by a weak acid mixture (about is composed of eighty-six parts of metal, and one part strong muriatic or nitrous acid, to thirty fourteen of oxygen in each 100 parts. The pro- parts of water). A plate of silver or platina portions in soda are nearly seven parts metal to being connected with the negative side of the two of oxygen; or seventy-eight metal and battery, a thin piece of pure potassa or soda is to twenty-two oxygen, in each 100.

be placed upon it, and a platina or silver con133. The metal obtained from potassa is called ductor, proceeding from the positive side of the potassium; it is lighter than water in the pro- battery, is to be brought in contact with the upportion of eight to ten. At common temperatures per surface of the alkali, which soon fuses at the it is solid, but soft and plastic. At a temperature points of contact: metallic globules shortly apof 150° it becomes fluid, and evaporates at a heat pear near the negative surface, and gradually rather below redness. In color it nearly resem increase in size, until a crust of alkali begins to bles silver, but it tarnishes immediately when form on their surface; at this moment they exposed in the open air, and can only be pre- should be removed by the point of a knife, and served under naphtha. Its attraction for oxygen instantly plunged under naphtha; or, if the exis so powerful, that it will detach that substance periment be merely intended to demonstrate from almost all its combinations; and the result their production, they may be brought in conof this action is its consequent oxidation and re- tact with the surface of water or nitric acid. It conversion into potassa. If thrown into water it sometimes happens that no globules appear; but immediately inflames

, floats upon the surface, if the contact be preserved for some time, and and burns with a mixed flame of white, red, and the alkali be afterwards raised, several will be violet; rendering the water, in which the expe- found imbedded in its under surface. If the acFitnent is made, alkaline. Similar phenomena tion of the battery be strong, it also sometimes Edsue when it is brought in contact with ice. happens that the globules inflame, and even deWhen moderately heated in oxygen gas it in- tonate at the moment of their production; it is fames and reproduces potassa. Its action on water therefore advisable not to bring the eyes too is always attended by the decomposition of that near during the experiment, or else to cover fuid; hydrogen is evolved, and the oxygen them with glasses. These experiments always combines with the potassium to form potassa. require great care to insure their success, which By measuring the quantity of hydrogen separated a trifling variation in the power of the battery, from water, by the action of a given weight of purity of the potassa, or moisture of the atmopotassium, the quantity of oxygen that metal com- sphere, may prevent. -Soda is rather more diffibines with to form potassa may be readily learnt. cult to decompose than potassa

, and therefore reEach grain of potassium detaches about 1.06 quires to be employed in thinner pieces; the cubic inch of hydrogen gas, and consequently pieces of potassa stould rarely exceed a quarter combines with half that quantity of oxygen.

of an inch in thickness, and those of soda one154. The metal obtained from soda is named eighth of an inch. sodium; it is rather lighter than water, nearly as 157. To prevent the loss of the alkaline bases 99348 to 1000. It has the color of silver; is during their separation, by the powerful action of less fusible than potassium, but tarnishes in air the air upon them, it has been proposed to effect

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