Negative electricity

“ We might speak of cold as negative heat precisely as electricians give the name of negative electricity to a relative deficiency of what they call positive electricity; but in the case of heat and cold it is found more convenient, and is more correct, to speak of different degrees of one and the same quality. The difficulty in the case of electricity is that at present science has no means of deciding whether positive or negative electricity has in reality the better claim to be regarded as absolute electricity. ”

“ In a galvanic battery the surface of the zinc plate is charged with
negative electricity.
According to the single fluid theory negative electrification consists
in a deficiency of electricity.
[Transcriber's note: Negative electrification is an excess of
electrons.]
Negative Element.
In a voltaic cell the plate not dissolved by the solution; the one which
is positively charged; the copper, platinum, or carbon plate in the
usual type of battery.
The current is assumed to flow from negative element to positive element
(the zinc plate) through the wire or other external conductor. ”

“ The electricity from glass is sometimes called vitreous, and that from sealing-wax resinous, electricity, but more frequently the former is known as positive, and the latter as negative, electricity—it being understood that these words do not imply the possession of a positive nature by the one influence, or of a negative nature by the other, but are merely terms employed to express the apparent antagonism which exists between the two kinds of electricity. ”

“ But it is manifest that the heavenly bodies, according to this theory, if they consisted of matter uncombined with electricity, would be in the highest state of negative electrification, and would repel each other. We have no reason to believe that they are in such a highly electrified state, or could be maintained in that state. The earth and all the bodies whose attraction has been observed are rather in an unelectrified state, that is, they contain the normal charge of electricity, and the only action between them is the residual force lately mentioned. ”

“ And although the potential acquired by a perfectly insulated piece of metal when exposed to ultra-violet light would depend only on the velocity of the fastest corpuscles and not upon their number, in practice perfect insulation is unattainable, and the potential actually acquired is determined by the condition that the gain of negative electricity by the metal through lack of insulation, is equal to the loss by the emission of negatively electrified corpuscles. ”

“ When the electrification is positive, that is, according to the usual convention, vitreous, will be a positive quantity. When the electrification is negative or resinous, will be negative, and the quantity may be interpreted either as a negative quantity of vitreous electricity or as a positive quantity of resinous electricity. ”

“ The electrical glow is therefore produced by the constant passage of electricity through a small portion of air in which the tension is very high, so as to charge the surrounding particles of air which are continually swept off by the electric wind, which is an essential part of the phenomenon.
The glow is more easily formed in rare air than in dense air, and more easily when the point is positive than when it is negative. This and many other differences between positive and negative electrification must be studied by those who desire to discover some thing about the nature of electricity. ”

“ The positive electricity will accumulate on the inside coating with which the knob is connected. It will then decompose the two electricities of the outside coating, driving the positive electricity to the earth, and there dissipating it, but attracting the negative to itself. There will thus be positive electricity on the inside, and negative on the outside coating. ”

“ When now we close the circuit, as before, a brisk effervescence takes place. Bubbles of gas rapidly form on the platinum wires and break away, rising through the liquid. Twice as many form on the negative wire as on the positive one. As these gases rise to the top of the bottle an equal volume of the water drips out through the small hole in the cork.
Fig. 153
Two amperes of electricity will liberate two fluid ounces of hydrogen at the negative pole and one [266] fluid ounce of oxygen at the positive pole, in five minutes. ”

“ Upon What the Kind of Electricity Excited Depends.—It depends on what a substance is rubbed with whether vitreous or resinous electricity is excited in it. Thus smooth glass rubbed with woolen cloth or silk will be positively electrified; while if it be rubbed upon the back of a cat it will exhibit negative or resinous electricity. So, also, if a resin, as gumlac or sealing-wax, [290] be rubbed with silk or woolen cloth, it will be charged with resinous electricity, but it will be charged with vitreous or positive if it be rubbed with sulphur. ”

“ There appears to me to be an unwarrantable assumption in confidently attributing the long absence from the heavens of marked electrical phenomena, and the failure of the electric machine to give its spark, to an unquestioned deficiency of atmospheric electricity. Electrical manifestations take place only when the plus and minus conditions are existing, in relation to each other, somewhat near, or not very remote; and the visible phenomena appear when the positive and negative rush together, so as to produce a polar equilibrium. ”

“ But if the body has been electrified it will communicate the electricity to the rod inside, and attract to itself the fluid of opposite quality; the same kind of electricity then is in action in the gold-leaf or needles, and they fly apart—repel each other. Supposing that positive electricity were first communicated, we can cause the contraction of the leaves or wires by applying a negative kind, which, meeting the positive, neutralizes it, and the wires collapse. ”

“ Electricity is of two kinds, positive and negative. The difference is, I presume, that one kind comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it. ”

“ Each has a higher potential than the acid, but their potentials are not the same. This electrification tends to pass from the place of higher to the place of lower potential, and the conducting wire allows this transfer to take place. As the difference of potential is kept up by the continued chemical action, the current is continuous, and not simply instantaneous, as in discharges of frictional electricity. As heat is produced by the burning of coal, so electrification is produced by the chemical burning of zinc. ”

“ The establishment of the principle that a certain electrolytic intensity is necessary before decomposition can be effected, is of great importance to all those considerations which arise regarding the probable effects of weak currents, such for instance as those produced by natural thermo-electricity, or natural voltaic arrangements in the earth. ”

“ In firing inflammable Substances, the Person who holds the Spoon in his Hand to receive the electrical Flashes, when the Finger of the electrified Person is brought near thereto, not only feels a tingling in his Hand, but even a slight Pain up to his Elbow. This is most perceptible in dry Weather, when the Electricity is very powerful.
There is a considerable Difficulty in firing Electrics per se, such as Turpentine, and Balsam Capivi, by the repulsive Power of Electricity ”

“ Electric currents passing through the human body expend their energy partly in heat and partly in electrolysis. So simple and harmless a thing as common salt would become a virulent poison if it could be electrolized in the body into its elements sodium and chlorine.
Let us make use of an electric current to decompose water into its elements, hydrogen and oxygen. I have a three-ounce wide-mouthed bottle (Fig. 153) and through its cork I pass two short pieces of No. 24 platinum wire by pushing a stout needle through first. ”

“ There is an advantage in producing a high temperature in the filament of the incandescent lamp, but there is no advantage whatever in producing heat in the wires that carry the current to the lamp. On the contrary, there is an objection to it; not only does the generation of heat mean a dissipation of energy, that is, of something which costs money, but it may be a positive danger, since a conductor becoming red-hot may set fire to a building. ”

“ If, then, we define electric displacement as that change which takes place in a dielectric when it becomes the seat of electrostatic energy, and if, further, we suppose that the change, whatever it be mechanically, satisfies certain well-known laws, and that in consequence certain pressures and tensions exist in the dielectric, electrostatic problems can be solved without reference to a charge of electricity residing on the conductors. ”

“ Physiological effects.—The power of the common electric current to shock and convulse the animal system, and when weak to affect the tongue and the eyes, may be considered as the same with the similar power of voltaic electricity, account being taken of the intensity of the one electricity and duration of the other. ”

“ With these adjustments and the use of iodide of potassium on paper, chemical action is sometimes a more delicate test of electrical currents than the galvanometer (273.) . Such cases occur when the bodies traversed by the current are bad conductors, or when the quantity of electricity evolved or transmitted in a given time is very small. ”

“ It is the property of all kinds of electrics, when they are rubbed by bodies different from themselves, to attract light substances of all kinds, to exhibit an appearance of light, attended with a particular sound, on the approach of any conductor; and if the nostrils are presented, they are affected with a smell like that of phosphorus. This attraction is most easily explained by supposing that electricity is produced by a fluid exceedingly elastic, or repulsive of itself, and attracted by all other substances. ”

“ Electricity in motion is transmuted into heat during the passage of a current along a thin wire, or any badly conducting substance—the wire is heated in consequence, and may even become white hot. Most frequently the energy of an electric current is spent in heating the wires and other materials that form the circuit. Now, the energy of such a current is fed by the burning or oxidation of the metal (generally zinc) which is used in the circuit, so that the ultimate effect of this combustion is the heating of the various wires and other materials through which the current passes. ”

“ The latest inventions of electrical science—the dynamo and the accumulator—afford remarkable instances of this convertibility of one primitive energy into different forms. In the instance just quoted of obtaining light from electricity by the voltaic battery, the cost has hitherto proved an obstacle to its adoption. The electrical energy is all obtained from the transformation of the heat produced in the cells by the chemical action on the metal used, which is commonly zinc. ”

“ It is greater, for instance, in dense air than in rare air, and greater in glass than in air, but in every case, if the electromotive force be made great enough, the dielectric gives way and its insulating power is destroyed, so that a current of electricity takes place through it. It is for this reason that distributions of electricity for which the electric resultant force becomes anywhere infinite cannot exist in nature. ”

“ What must be that mutual action of molecules having unlike motions, which, as we see, is the universal antecedent of electrical disturbance? The answer to this question does not seem difficult to reach, if we take the simplest case—the case of con­tact-elec­tri­city. When two pieces of metal of the same kind, and at the same temperature, are applied to one another, there is no electrical excitation; but, if the metals applied to one another be of different kinds, there is a genesis of electricity. ”

“ In the arc-lamp the electric circuit is broken at the point where light is required. In glow or incandescent lamps the current is only hindered by the interposition of a bad conductor of electricity, which must also be incombustible. Just as a current of water flows in less volume as the bore of a pipe is reduced, and requires that greater pressure shall be exerted to force a constant amount through the pipe, so is an electric current choked by its conductor being reduced in size or altered in nature. ”

“ If the tube be exhausted of air, a non electric lining in contact with the wire is not necessary; for in vacuo, the electrical fire will fly freely from {78}the inner surface, without a non-electric conductor: but air resists its motion; for being itself an electric per se, it does not attract it, having already its quantity. ”

“ The like may be said of a dead Animal; but Wax, Pitch, Resin, and the Tribe of Non-electricables, never had their Existence from Nature only; and therefore they are quite of a different Tribe. For what I say is, That whatever had once Fire in it is capable of being electrify’d. Those called Electrics per se, having no Fire in them, when, by Friction, Fire is collected on their Surfaces, it is either driven from thence into the Air, or into some Electricable, and so it joins with that Fire which naturally belongs to it. ”