The patentee claims the cooling and congealing of water and other fluids by means of compressed air conveyed through a tube provided with a cock, and surrounded by another tube provided with a cock, (and communicating with a reservoir of water,) and allowing it to suddenly expand, while surrounded with the water, in such a manner as to cool or congeal the water, on the principle that air, by suddenly expanding, absorbs heat, its capacity for heat being increased, as described."

To D. SAUNDERS, of Cincinnati, Ohio; J. G. BISSET, of Covington, Kentucky; and S. SAUNDERS, of Pittsburgh, Pennsylvania, for making tyre for railroad wheels.

THE following is the mode of procedure:-A pile of iron and steel is made as follows:- first a large bar of iron, then a thin bar of steel, then another bar of iron, the latter being thin, and serving only as a protection to the steel from being burnt in the process of welding;—the whole is then welded. The bar is then passed through a series of rollers, giving the required shape to the tyre, shrunk on to the wheel, and the thin plate of iron turned off to expose the steel to the surface.

The patentees claim the manufacturing of tyres for railroad wheels, as herein described.

TO WILLIAM CLAYTON, of Marshalton, Pennsylvania, for an im-
provement in the brake for railroad cars.

THE patentee says,
"This brake consists of two horizontal pa-
rallel sliding bars arranged between the wheels below the frame,
made to slide alternately and transversely back and forth, in cor-
responding openings in plates, fastened to the frame, or in suit-
able boxes, by a right-angled connecting rod, connected by pins
to the said bars, and operated or vibrated back and forth by means
of a connecting rod and vibrating lever, working on a fulcrum
attached to the frame; two rubbers being attached to each rod on
the outside and inside of the edges, so as to produce eight rubbing
surfaces simultaneously against the inner and outer faces of the
wheels, instead of the peripheries of the wheels, as in the old
plan-each bar working through the rubber of the corresponding
bar on the inside of the wheel-so that as the lever is moved to-
wards the car, for the purpose of arresting its motion, the four
rubbers will be caused to embrace or gripe the edges of the wheels
in the manner of a vice or pair of tongs."

The patentee claims constructing the brake, in the manner described, to gripe the rims of the wheels, and apply the friction to the sides thereof (instead of the peripheries), or other modes substantially the same, by which analogous results are produced.

;

ON THE NATURE AND OPERATIONS OF THE

IMPONDERABLE BODIES.

BY IGNOTUS.

In laying before our readers a series of papers under the above title, the arguments of which are founded on hypothesis, as yet unsupported by experimental tests, we may perhaps be considered as deviating from the line of practical utility, which the general tenor of the London Journal may have led some to infer was the sole chord we were desirous of sounding. But, in defence of this innovation (if such the papers now following, and those which are to succeed, must be called), we would state, that nothing can tend more to practical utility than the discovery of the properties and character of those subtle fluids-electricity and magnetism, which, as far as we are yet enabled to discern, intermingle with all the elements, and form as it were a part of animate and inanimate nature. If therefore the ingenious hypothesis of our contributor should, on a more certain knowledge of the subject, be found untenable, his writings may yet have served an important purpose, viz., that of keeping up attention to a branch of science, the key to which is now but dimly present to the greatest philosophers of the age.

CHAPTER I.

ON ELECTRICITY.

WHEN Electricity first began to be admitted as a distinct and important science, two theories were advanced to explain its phenomena The one proposed by Dr. Franklin attributed these phenomena to an homogeneous fluid, which, when collected in an accumulated state on one side of an electric system, rendered it plus or positively electric; this being invariably accompanied by a diminished quantity of the fluid on the other side of the system, which was then pronounced to be minus, or negatively electric. The second theory, mainly advocated by Du Fay, asserted the existence of two distinct fluids, one of which was termed vitreous or positive, the other resinous or negative electricity. One or other of these theories has ever since been adopted by all electricians.

It is not the object of the present essay to discuss the respective merits of the above theories, but to propose a modified one, which it is conceived, if established, would have a tendency to improve the science of electricity, as it is generally denominated,

It

in respect to its now admitted varieties, and at the same time to throw new and important light on the operations of nature. is necessary, however, to state, that the views which will be advanced lay claim to no higher dignity than that of an unconfirmed hypothesis; and instead of being based on experimental research, will be found to derive their support almost exclusively from analogies and inferences deduced from previously established facts. This admission in primo limine may possibly startle the mathematical mind, and lead many readers at once to throw aside the work; such critics are, however, earnestly entreated to withhold their condemnation until they have contemplated the hypothesis as a whole, and seen the harmony which the principles advanced maintain in all their various applications.

It is now nearly twenty years since the author (at that time a believer in the Franklinian view) was amusing himself with a series of experiments, with the ordinary electric machine, on the conducting powers of different substances,-as, for instance, mercury, iron filings, spirits of wine, water, and various metallic oxydes,—inclosed in glass tubes, armed at each end with brass knobs. In the course of these experiments he was impressed by the differences of appearance or effect manifested by the electric sparks proceeding from the extreme knobs after having passed through different conducting media; from one, the colour was blue; from another, inclining to red; from a third, green; and from a fourth, white :-the sensation received also differed; in one case, it was a shock; in another, tingling; in a third, burning; in a fourth, as if pricked with a pin, &c. &c. Reasoning on these facts, he could not but think, that if, as the Franklinian hypothesis supposed it, the electric fluid were a homogeneous matter, it ought not to exhibit these varieties of character; and that the only differences to be observed, must refer themselves to the quantity of, or rapidity with which, the fluid was permitted to pass, by the conducting power of the medium producing a greater or lesser spark in one case than in another; here, however, was an apparent change in the positive character, if not in the nature of the electric fluid; and it was not impossible that it might have undergone a species of decomposition in its transit, and either acquired some new principle from the medium, or imparted to it a portion of its own. In the latter case, in particular, there was evidence of chemical action having taken place; and the inference followed, that the electric fluid might be a chemical agent, comprising within it more elements than one; and, consequently, be entitled to be regarded as a compound body. This inference (whether strictly justifiable or not) led to a consideration of what might be the nature of this presumed constitution of the electric fluid, and the present essays are the result.

It occurred to the author, that the phenomena presented in the charging of a Leyden jar by the ordinary electric apparatus were calculated to throw some light on the subject. Here it was

evident that a quantity of that principle which was termed positive electricity, became accumulated within the interior of the jar; while, at the same time, a quantity of the negative state of the fluid collected on its exterior. This latter circumstance was attributed to the electricity accumulated within, exerting its repulsive force through the sides of the jar upon the particles of electricity of a similar kind situated at the exterior; while its attractive force determined the particles of negative fluid to assume the place of the repelled positive fluid; and thus, while the interior became positively, the exterior became negatively charged. This may be illustrated by a diagram.

But the above is not the full state of the case :-in conformity with the theory, the positive electricity at P, would not only repel the positive electricity on the outside of the jar, and attract the negative electricity at N, but the latter would also repel the negative electricity previously contained within the jar towards its centre; while the positive electricity repelled from N, at the exterior, is attracted by the negative electricity of the latter, and assumes a position at its exterior. This is expressed by the following diagram:

Under the above state of circumstances, the theories of Franklin and Du Fay do not explain why (the rotation and excitement of the cylinder being discontinued) the positive fluids r, aud N, N, in the interior, and P, P, and N, at the exterior, being in juxtaposition, should not respectively unite and form neutral electricity

without the necessity of a conducting body applied between N, and P, and N, N, and P, P, to produce that effect; nor do they explain how the necessity for such conducting medium arises; or the manner in which the rotation or the excitation of the cylinder operates in producing the arrangement of the respective. fluids within and without the jar.

In the theory, which it is the object of the present essay to advance, it is proposed to assume, with respect to the Leyden jar, a state of circumstances very similar to that expressed in the first diagram,-namely, that the interior is charged with positive, and the exterior with negative electricity. A more important assumption, however, is, that these two principles consist of perfectly distinct elementary chemical principles,-the one being imponderable in its nature, the other more gross and ponderable; the former of which may be designated by the term magnetine, analogous to, or in some measure synonymous with, negative electricity, the latter by the term electrine, in some measure synonymous with positive electricity. The annexed diagram will illustrate this:

The above principles, magnetine and electrine, admit of entering into chemical combination, producing, by their union, a compound body, which constitutes neutral electricity; and which will occasionally hereafter be designated as magnetide of electrine, the important nature of which will in due time be developed. This matter exists abundantly in many of the component bodies of our globe, particularly near its surface, and is found in large quantities pervading, and forming an essential part of the atmosphere.

The above combination of magnetine and electrine admits of being disturbed or decomposed by a variety of causes; one of the more common of these, is the subjecting it to friction produced between other bodies. Here the decomposition appears to result from some operation of the heat occasioned by the friction; and it will hereafter be seen, that heat is the great opponent to all the chemical combinations of magnetine. It is, however, by no means improbable, that the compression which the particles of electrine sustain, may also importantly influence the elimination of the magnetine. It is to the decomposition of magnetide of electrine, resulting from the friction of the cylinder