the imponderable principles; and they may be generally expressed by one or other of the following symbols:

E. C. . L. C.

E. H. M. L. C.

E. C. H. M. L. C.

An example of combustion arising from the combination of two bodies, neither of which contain electrine, is now offered. The agents selected for this purpose are the metal aurum, and the pro-metal chlorine.

When a portion of gold leaf (Au. M. L. C.) is thrown into a vessel of chlorine gas (Cl. M. L. C.), chemical action takes place ; lumine and calorine are abundantly evolved in a free state, and probably a quantity of magnetine; while the gold and chlorine combining together, and retaining the remaining portions of the imponderable principles, form chloride of gold, or Au. Cl. M. L. C. This product, according to the hypothesis, may be regarded as a bibasic radical, capable of entering into new combination with any other body, whose relative imponderable constitution admits of being disturbed by it.

It may be inferred, as lumine is not generally disengaged, or at least manifested in secondary or plural compounds, that it has either been wholly given out in the primary decomposition, or that only sufficient is retained to maintain the proper constitution of the matters then and subsequently to be generated.

Examples of chemical action, dependent on the principles advanced, which may be considered as constituting a general law, might be multiplied almost ad infinitum. It is admitted, however, that the various equivalents of the imponderable constituents in the different chemical elements, and their numerous and various products, remain, and probably will ever remain, undeterminable by chemical science.

CHAPTER IX.

THE HYPOTHESIS EXPLANATORY OF VOLTAIC ACTION AND

CATALYSIS.

ONE of the most interesting applications of the hypothesis, is the explanation it is capable of affording respecting the nature of what has been termed voltaic electricity; or, as connected with its property of effecting chemical decomposition, electrolysis.

In considering this subject, it is intended to take a view of the phenomena manifested by the common simple voltaic battery, composed of zinc and copper plates, and acted upon by the intervention of hydrochloric acid.

In the above modification of the voltaic battery it is probable, if not certain, that in the resulting voltaic action, no influence of the principle of electrine or oxygen is involved; for notwithstanding the hydrochloric acid employed is in combination with water, yet, seeing that the action which takes place between it and the zinc produces chloride of zinc only, without any admixture of oxide, it is fair to infer that the water acts merely as a menstruum for the condensation or solution of the acid, and takes no part in the chemical changes which are induced. The above arrangement may therefore virtually be considered as comprising three distinct agents only, namely, -zinc, copper, and hydro

chloric acid.

According to the views previously advanced (Vol. xxxii. p. 207), each of the above agents comprises, in its respective constitution, the requisite quantity of latent magnetine, to confer on its radical base its proper metallic or pro metallic qualities; the quantity or equivalents of such magnetine differing in each respectively. When two of them are brought into contiguity, the tendency to combination coming into play, an union of the bases takes place, and a new compound is formed, the capacity of which for magnetine is less than that of the bases collectively; the consequence is, that a quantity of free magnetine is disengaged. Thus the chlorous base unites with the zincous base, producing a chloride of zinc, comprising a lesser quantity of magnetine than the chlorine and zinc previously contained, the remaining magnetine. being set at liberty.

It is by virtue of this principle that the phenomena of voltaic force are deemed explicable. The subject is so important, that, in the subsequent illustration, a degree of repetition will be excusable.

When a voltaic battery, constituted as above, is put in action, the following series of effects is induced:-In consequence of the tendency of zinc and chlorine to enter into combination, a portion of the hydrochloric acid, in immediate contact with the zincous plate, is decomposed, and chloride of zinc formed; which latter compound is incapable of retaining in its constitution the whole magnetine, previously comprised in those portions of the zinc and copper, which have been acted upon; in consequence, the superfluous magnetine is set at liberty, passing at the instant into what may be termed a free and nascent state. At the same

time that the above takes place, the hydrochloric acid, having parted with its chlorine, the hydrogen previously in combination with it is disengaged also in a nascent state. The above may be regarded as the first series of phenomena resulting from the process.

The next step in the operation is the manner in which the free magnetine and hydrogen, eliminated as above, dispose of themselves. To explain this, it is necessary to assume the formation of a new and hypothetical chemical agent, produced by an instantaneous or immediate combination of the magnetine and hydrogen. According to the hypothesis, hydrogen is itself a compound of an abstract radical base and magnetine, and, therefore, might be represented as H.M., in which condition the two elements may be regarded as mutually saturating each other; there is, however, nothing at variance with the acknowledged facts of chemical science in supposing that these elements admit also of combination in different proportions or equivalents; thus, for instance, until of late years, oxygen was not considered as possessing any other ratio of combination with hydrogen than in those equivalents which form water; it is now, however, found constituting a peroxide, under an affinity, it is true, which is easily resolved. Under this consideration it is intended to maintain that, in the case in point, the disengaged magnetine enters into union with the disengaged hydrogen, giving rise to what may be termed bi-magnetide of hydrogen, or H. M.

The following properties are now claimed for this bi-magnetide of hydrogen :-

1st. It exists in a liquid state, and therefore manifests no gaseous bubbles, or appearance cognizable by the eye.

2nd. It possesses a greater affinity for copper than for hydrochloric acid.

In consequence of these properties the bi-maguetide of hydrogen, when formed near the zincous plate, traverses invisibly the hydrochloric acid until it reaches the cuprous plate, to which transit it is determined by its affinity for the copper.

The bi-magnetide having thus arrived at the cuprous plate, a new decomposition takes place. The copper has no strong affinity for the hydrogen, but a powerful disposition or capability to receive the magnetine; the hydrogen is, in consequence, set at liberty, and escapes in bubbles by the side of the copper-plate, while the magnetine, in a free state, enters into the copper, and renders it per-magnetic, distributing itself instantaneously into equlibrium throughout the pores of the metal. In the same way it now passes into the conducting wire, and eventually to the zincous plate, producing, in this act of distribution, a magnetic current, and constituting what has been termed the "electric force." If the operation be interrupted, as, by separating the connecting line, the charge of free magnetine passes off into the surrounding atmosphere, and the magnetic force ceases; otherwise, the magnetic current is perpetuated, -the apparatus continuing in a condition to exhibit magnetic excitement until the chemical action between the zinc and hydrochloric acid is exhausted.

The foregoing view may be illustrated by the following diagram:

EXPLANATION OF DIAGRAM.

A. Zincous plate of voltaic battery.

B. Cuprous plate of ditto.

c. Conducting wire between A, and B.

Hydrochloric acid.

<** Bi-magnetide of hydrogen produced at the zincous plate, and passing in a current through the hydrochloric acid to the cuprous plate.

Hydrogen liberated by decomposition of the bi-magnetide of hydrogen at the cuprous plate.

Magnetine, in a free state, liberated by decomposition of the bimagnetide of hydrogen at the cuprous plate, and passing into that plate; then through the conducting wire to the zincous plate; thus constituting the voltaic force.

It remains to notice the production or disengagement of heat, and, occasionally, of light, which are attendant on voltaic action: 1st. The conducting wire will always be found more or less heated as the voltaic force passes along it. This may be explained by considering that the rapid passage of the magnetine through the wire (particularly when the antagonism between magnetine and calorine is taken into account) will necessarily compress the free calorine comprised within the conducting body, and thus induce an increase of sensible temperature, the degree of which will be commensurate with the condensation produced :thus, if the wire be of relatively small diameter, and the voltaic current copious, the former will become even red hot; while, vice versa, if the wire be relatively large, and the voltaic force feeble, little sensible increase of temperature is induced.

2nd. It has previously been stated that magnetine and lumine are rarely, if ever, found separate; and it is, consequently, fair to infer that they exist together in the voltaic current, and that the visible manifestations of the latter may result from the concentrated state of the former, and the rapid movement to which it is subjected; such manifestations, however, do not take place, unless a degree of interruption be made in the current, as by dividing the conducting wire, and detaching the extremities more 2 L

VOL. XXXII.

or less from each other; by which means, the magnetic stream is compelled to pass through a greater or lesser stratum of atmosphere;-whether the light produced arises or not from the magnetic fluid impinging on some terrestrial body, as is the case with the solar rays, is a point which it is impossible at present to determine this, however, is not improbable. Were the theory of vibration admitted, the production of light, under the intense voltaic impulse, would readily be accounted for.

In the foregoing example it is assumed that no agent has been employed which contains electrine or oxygen; and it is desirable to shew the operation of voltaic action with the intervention of an element of this nature. Let therefore water be substituted for the hydrochloric acid. On putting the battery in action, a portion of the water is decomposed, its oxygen entering into combination with the zinc, and forming oxide of zinc; while the hydrogen entering into union with the magnetine given out from the zinc as before, passes on in the state of bi-magnetide to the copperplate. The remaining series of actions induced, in no respect differ from what has been previously detailed, as occurring when hydrochloric acid has been used.

It may be interesting, as an additional illustration, to apply the present principles to an explanation of the well-known experiment by which Sir Humphrey Davy first detected the metallic constitution of potassium. This was effected by employing that variety of voltaic battery in which the conducting wire between the positive and negative plates was intercepted or divided, and which battery was excited by means similar to those which have been described. Magnetic circulation was then established by bringing the two opposite but divided poles into contiguity by the interposition of a moistened portion of hydrate of potash placed upon mercury, the negative electrodic extremity being introduced into the mercury, and the positive one into the potash. The current of free magnetine passing from the cuprous plate now makes its way through the intervening potash, decomposing the latter in transitu; a portion of the magnetine enters into combination with the metallic base of the potash, and converts it into potassium; while the oxygen is separated, and set at liberty at the opposite electrode.

Some interesting inferences may be drawn from the principles advocated in the present chapter. In a former portion of the work (Vol. xxxii., p. 64,) it has been maintained that the electric action resulting from the common electrical apparatus is, with respect to one of the constituent elements engaged therein, essentially dependent on the presence of electrine; while, in the present chapter, voltaic action appears capable of being induced without any co-operation on the part of that element. It follows, that there exists an important difference in the nature of the two kinds; both, however, being dependent upon the influence of magnetine. In voltaic action, it has been attempted to shew that magnetine