escent spectrum of these salts, namely, the presence of NEWS. narrow well-defined flat bands. Above 110, where the general absorption begins, the bands not only seem darker, but more blended on their edges. In Fig. 9 the first spectrum will indicate this.

shown in 2 of Fig. 10. This is the substance generally known as the uranic oxychloride, or, in commerce, as uranic chloride. The general character of its spectrum is that which may be regarded as normal to uranic salts-a series of rounded bands terminating most abruptly on the upper edge. In transmitted light, it produces a very marked absorption spectrum, which is shown at I of Fig. 11. When the neutral oxychloride is dissolved, it forms a rich orange solution, which has a very great general absorption, and shows some bands; it is almost devoid of fluorescence. The addition of a little hydrochloric acid greatly reduces its colour, and, as with the uranic acetate, clears up its spectrum, which then shows the bands exhibited in 3 of Fig. 11. These same bands are shown by the solutions of the ammonio and potassio double salt, and lead us to conclude that the double chlorides, like the double acetates, only exist as such in the solid or crystallised state. If the uranic oxychloride is allowed to crystallise from a very acid solution in a desiccator, it will form a transparent yellow mass, whose specturum will be of the duplex character indicated in 4 of Fig. 1. This we have little doubt indicates the presence of two hydrates, but it is curious to observe how regularly this spectrum appears whenever the uranic oxychloride crystallises from an acid solution. We encountered it constantly in our unsuccessful attempts to form double salts.

Ammonio-Uranic Oxychloride, U2O3CI+NH4C1+2HO. --Though this substance is often so difficult to form, as has been already stated, yet, once formed, if there is a slight excess of hydrochloric acid present, it may be fused, and will crystallise instantly on cooling. If kept in a fused state until a partial decomposition has taken place, an opaque yellow body is formed, which fluoresces very brightly, and yields a continuous spectrum. The normal salt is, perhaps, one of the most beautifully fluorescent in the entire series, and it yields a spectrum equally remarkable. This is represented at 1 of Fig. 10. Each band, as we may say, is here made up of from three to five narrow stripes variously shaded, and this, combined with their rich colouring produces an effect of wonderful beauty. The absorption spectrum of this salt, also of a somewhat composite character, is represented in 2 of Fig. 11.

Potassio-Uranic Oxychloride, U2O2C1+ KCl+2HO.This salt, in all its fluorescent relations, so closely resembles the ammonio salt just described, that it is only necessary to note this fact, and say that all its bands are a very little raised in the spectrum, but this difference is too small to be represented in a cut on the scale here employed. (To be continued.)

ON THE

SPONTANEOUS ASCENT OF LIQUIDS IN VERY
NARROW SPACES.

M. DECHARME, having a short time since studied the
recently experimented on the ascent of these liquids in
ascent of a large number of liquids in capillary tubes, has
ranked in the same order, in this case, as regards height
porous paper, with the view of ascertaining whether they
and velocity of ascent.
follows:-
The general results are as

(1). The ascending movement of liquids in strips of blotting-paper, compared with that in capillary tubes, presents essential differences, as well as numerous similarities. The curves obtained in both cases resemble each other in being sensibly divergent from parabolas, and tending, in the latter part, especially to the hyperbola; but in the blotting-paper the phenomenon is more complex than in the tubes, first from the influence of the hygrometric state of the air, and next because there is sometimes dialysis as well as capillarity.

(2). Each liquid has a velocity of ascent proper to it (papers of constant size being used in each case, and all other conditions being the same). The strips used were 15 or 30 m.m. in breadth, and all from the same sheet.

(3). For different liquids, in the same conditions, the velocities of ascent are not in direct proportion to the height ultimately reached. Thus nonvolatile substances, as concentrated acid or saline solutions, and substances largely absorbent of water, sometimes rise slowly; but their movement may continue for days, or even for weeks.

(4). The velocity is, moreover, neither in inverse proportion to the total duration of the movement, nor simply proportional to the density of the liquid. The law depends on other elements, such as temperature and hygrometric state. The annexed

curves illustrate these statements.

(5). With capillary tubes, only one liquid was met with which had a velocity constantly superior to that of pure water; it was an aqueous solution of chlorhydrate of ammonia. With the papers, more than forty liquids have been found in a total of 207 (i.e., about a fifth), having both a velocity and a final height superior to that of water. Among these may be cited chlorhydric, nitric, oxalic, tartaric, and citric acids; chlorides of calcium, zinc, and lead; chlorhydrate of ammonia; nitrate, bichromate, oxalate, urate, cyanurate, and oxalurate of ammonia; iodide and bromide of ammonium; chlorate, perchlorate, persulphate, and bioxalate of potash; sulphocyanide, bromide, and cyano-ferride of potassium; sulphate of soda, &c.

(6). For the same liquid, all other conditions equal, the velocity and the capillary height increase with the breadth of the paper.

(7). For the same liquid, and the same breadth of paper, but for strips of a thickness double, triple, quadruple, &c. (multiple strips formed by superposition of several equal strips), the capillary velocity, and the duration of the ascent increase very sensibly with the thickness.

(8). A slight pressure exerted on these multiple strips, better insuring their contact, favours the ascending movement; but, beyond a certain limit of strength, pressure on a sufficiently extended surface diminishes the velocity of ascent, and may even arrest the movement altogether.

(9). The inclination of the paper has a positive influence on the velocity, the length of course run by the liquid, and the total duration of the movement. In every case there is not a proportionality between the heights or the velocities observed and the variable elements, breadth and thickness of paper, pressure, &c.

(10). For all liquids, the velocity of ascent increases with the temperature. Still, if at the beginning of the movement such increase appears, it is presently counterbalanced and ruled by the evaporation, which retards, and

It is not necessary, then, to have recourse to an extreme fineness of vessels, to explain the ascent of liquids in the tissues of plants. It is sufficient to remark that the saline solutions which naturally exist in the soil rise higher than pure water; sometimes to double the height, e.g., the following salts:-Nitrate, sulphate, carbonate, bicarbonate of potash, nitrate of lime, carbonate of soda, chlorides of potassium and of sodium.

THEORY AS TO THE

A. B. M.

Within the bobbin is a larger hole than usual. The two ends of this wire so coiled are connected with the reflecting galvanometer. The reflected light from this lamp is now visible and stationary upon the screen. You are aware that motion of that reflected speck of light will be the consequence of electricity passing through the coils of the galvanometer. Now, observe that, without either chemical or physical agency acting upon or in contact with the wire, we shall obtain a manifestation of electrical disturbance within the copper wire. Let the end of this steel magnet be introduced within the bobbin: you see that the speck of light immediately moves. Except in Again, if the other end of the steel magnet be brought within the bobbin, you see the speck of the galvanometer moves in an opposite direction. Thus may be shown one form of electrical induction.

FORMATION AND PROPERTIES OF OZONE. this manner, copper does not manifest electrical properties.

By R. LAMONT.

WHEN phosphorus is allowed to oxidise in air, or oxygen
gas, phosphorous pentoxide and ozone result. An atom
of oxygen cannot exist in the free state, but a molecule
can, which in this case consists of two atoms (0-0).
Phosphorous pentoxide consists of a molecule of phos-
phorus combined with two molecules + an atom of oxygen.
When phosphorus is left to oxidise in oxygen, the molecule
of phosphorus combines with two molecules of oxygen,
but, this not being sufficient to form the pentoxide, it must
have another atom of oxygen, which it can only get by
splitting up a molecule of oxygen-one of the resulting atoms
combining with the phosphorus, the other atom going to
a molecule of oxygen to form ozone (O-0-0). If the ozone
which has been formed is allowed to remain in contact
with the phosphorus, it is decomposed thus-
P2+(0-0-0)+(0-0-0)+(0-0-0) = P2O5+ (O-0)+(0-0).
The powerful oxidising properties of ozone may be
accounted for by supposing that the three atoms of oxygen
are so loosely combined that, when it comes in contact
with an oxidisable substance, one of the atoms combines
with this substance, the other two going to form a molecule
of oxygen.

Now, with that phenomenon we are perplexed. This property of induction manifests itself at times and in ways of which we know nothing. For example, if a copper wire were laid upon this floor, and another copper wire were laid parallel to it on the floor below; and if any current of electricity passed through the wire on this floor, the one below would answer to it, although there was not any apparent contact or communication between them. The laws which govern such electrical manifestations as these are very partially understood, and therefore the measurements of the results of these laws are for general use almost valueless. We must, however, for the present assume that the nature of the phenomena of electrical induction is clear.

The next stage in obtaining electricity is by means of what is called a galvanic cell. Such a cell usually consists of two different metals and one or two liquids. Whatever may be the arrangement, the electricity developed may be estimated by the intensity of chemical affinity during the process and at the time of the measurement. But the whole of this question of chemical affinity must now be assumed, and some of the affinities explained operating in this cell. A chemical action takes place upon a square inch of one plate, and it is met by an action upon a square inch of the other; therefore, on every square inch an action is produced. Between the two plates there is something (say the liquid) which causes the action; it is, in fact, the presence of this liquid which calls the chemical affinities into play.

ANALYSIS OF GREAT SALT LAKE WATER. in the last lecture are probably the chemical affinities

By H. BASSETT.

HAVING a small quantity of the above water placed at
my disposal by Dr. W. Marcet, F.R.S., who collected it
himself last August, I thought an analysis might be of
interest, especially as I have not found any account of it
in books of reference. The water has a slight alkaline
reaction, and a specific gravity of 1102 at 17°.
Total solid residue, in 100 parts, by weight=13.67.
In 100 Parts by Weight.

Chlorine

SO4

7.36 0.88

Sodium

3.83

Potassium

0'99

Calcium ..
Magnesium

'0'06

0'30

13'42

ON THE ENERGIES OF THE IMPONDERABLES,

WITH ESPECIAL REFERENCE TO THE

A word must now be introduced which will often occur during the lecture, and it is one which performs an important part in the measurement of electricity of the character which men utilise, i.e., resistance. Indeed, this resistance to the free passage of an electric current is now our chief business. Whilst the size of the plates in these cells is increased, the resistance to the free course of the manifested electricity is not decreased. Thus, for instance, from a square inch of one plate there is a current of electricity meeting or co-operating with that developed from a square inch of the opposite plate. Whatever may be the energy of the chemical affinity upon one square inch, it is met by the energy of the chemical affinity upon the opposite square inch of the other, and that energy has to overcome the resistance of the liquid between them. Now, then, assume that each of these plates is enlarged by the addition of another square inch. This introduces an

MEASUREMENT AND UTILISATION OF THEM.* additional quantity of liquid, and we have to overcome

By the Rev. ARTHUR RIGG, M.A.
(Continued from page 224).

LET us now pass on to the mode of obtaining electricity from chemical action. Before doing so a phenomenon should be noticed, which disturbs results very seriously, and which is, at present, not understood. Here is some copper wire, covered with cotton, coiled from end to end, say five or six times along this large bobbin of wood.

*The Cantor Lectures, delivered before the Society of Arts,

the resistance of this liquid, The difficulty of overcoming
the resistance of the intervening liquid is such that,
however much we multiply the number of square inches,
further electrical resistance. Hence, however large may
we also introduce more liquid, and, by so doing, add
be the plates, we do not overcome the resistance more
easily. That led to the contrivance of thus coupling-up

which is familiar under the name of a cell-battery.
in what is called "a series" in the form you see here, that

It may perhaps make clear what is a difficulty to many minds, if an attempt be made to explain how it is that an

it is retained in the same position. Let a disturbance take place in the evenly flowing water, and the stick will no longer retain either steadiness or direction. Suppose, now, that this needle is retained in a certain direction by the influence of what we may call the stream of terrestrial electricity flowing through the atmosphere of this room. (That such a stream is so flowing through the atmosphere shall be made apparent presently.) From these four cells of a galvanic battery a current of electricity may be caused to pass along the wire which surrounds this wooden ring. The arrangements are made, and such a current is now passing. What is the consequence? The even flow of that which retained the needle is disturbed, and the needle answers as the stick in the water would have done to the disturbing causes. Clearly the nature and extent of the invisible disturbance may be estimated - indeed measured-by the motions of the visible needle, just as a new position assumed by the stick would measure the disturbing influence on the stream.

electrical current which passes when cells are coupled-up | string. So long as the stream flows steadily past the stick "in series," that is, one after the other, is more intense than when they are combined as one large single cell. Supposing these two plates, each I square inch in area, were the only two concerned, therefore there would be a certain resistance to be overcome. The chemical affinity of one such combination not only overcomes that resistance, but leaves a surplus of electricity, which surplus is said to run along the outside wire, and may produce what we call a telegraphic dispatch. Now, suppose that, in addition to those two plates, there are two others of the same size and material in a cell behind them. Between these second plates there is also a resistance similar to that between the first two. Those two second plates, however, also produce a surplus. Now, as that surplus passes over, it continues its way through the previous plates and wire, and the consequence is that, when once the resistance of its own cell has been overcome, the surplus electricity can pass through the other cells without any resistance, and, therefore, we are enabled to add the surplus of one cell to the surplus of the next, and so on. Hence, when combined in the form in which they are combined in this battery, we are manifestly enabled to pass along the connecting wire successive equal amounts of electricities, and these, flowing so very closely behind each other, produce an effect upon any resistance similar to that produced upon a slab of marble or of glass by the forcible driving against it of small grains of sand in a continuous stream. These grains penetrate, and, as it were, bore holes even in hardened steel; so these successive electricities are, as it were, continuous, and thereby overcome great resistances. It may, in connection with this, be remarked that, perhaps, in some such way as now described, the mighty energies of affinity may be accomplished by this clashing of millions upon millions of atoms and molecules. This may explain how and why it is that these cells thus arranged "in series " are under certain circumstances more effective than when the same amount of liquid and metallic elements operate as one cell only.

Electricity thus, or by other means at our disposal, is now to be measured. Two things are especially before us now. One to make clear how this measurement is made; the other to endeavour to make clear how the resistance of various bodies, be they wires or liquids, is also measured.

This electricity is measured in a very simple way. All the apparatus is here, but as it would take too long to show experiments in detail, perhaps you will kindly accept a statement of facts instead of a visible reproduction of them. In these cells is being produced a quantity of electricity, which is to be measured, much as sugar is measured by the pound, or liquids by the quart. The way it is measured is either by the chemical decompositions that it can produce, or by the amount of heat it can develop, or by other means, as, for instance, its effect upon the magnet in a given time.

This seems a convenient opportunity for directing attention to a galvanometer, which is arranged upon a plan by which is shown the amount of decomposition effected by the current indicated by the place of a needle on the dial. The gentleman who designed it had in view only a manufacturer's requirements. The measurement effected by such a galvanometer is not of that character with which this lecture is to be concerned, and therefore further reference to this particular one is not requisite.

To consider a mode of measurement we must recur to those elements-mass, space, and time. The apparatus on which my hand now rests consists of a wooden ring, about 10 inches in diameter, having coils of copper wire round it. Within this circular box with a glass top is a small magnetised steel needle. Now, the small steel needle assumes a certain position in consequence of the influence of terrestrial magnetism. Such an influence as this is not unlike a stream of water in a brook upon a short stick, one end of which is tied to a stake by a

The promise to let you have proof that there are currents of electricity passing through the atmosphere of this room may now be redeemed. Here is a circular wooden ring, with wire round it as before. You may notice that it can be turned as a lookingglass in its frame. The ends of the wire coiled round it are now connected with the wires of the galvanometer, the mirror of which reflects that speck of light on the screen. The looking-glass mounted ring is placed in reference to the (so-called) current of electricity always passing through the atmosphere, that were there a glass in the frame the current would beat upon that glass. If the frame be turned onefourth round, then the current will pass parallel to the face of the frame. Or thus:-If the frame of the wireenclosed ring be placed parallel to the direction of this magnetised needle, then the current of electricity through the atmosphere of this room is passing parallel to the ring. To move it, therefore, from this position to one at right angles to it, it is clear that the circumferential wire must, as it were, cut the stream of electricity, if there be one. Now, so cutting it, there will be a disturbance in the electrical condition of the wire, which may be manifested by a motion of that speck of light. Observe now, that every motion of the frame causes a motion in the needle of that galvanometer, which is placed on a stand far removed from the table on which the motion of the frame takes place.

The two experiments now made may satisfy you:(1). That there is what, for want of another name, we may call a current of electricity passing through the air; (2) that disturbance of the uniform quiet flow of this current may be caused; (3) that this needle is sensitive to such a disturbance; and (4) you will perhaps accept my word for that which time alone prevents being illustrated, viz., that the amount of this disturbance may be measured by the needle-that is to say, the greater the disturbance the further will the needle be moved from its original position.

It will be obvious to all that the amount of motion in the needle for any given disturbance will depend upon its sensitiveness. Hence, two needles may or may not move equally from the same cause. A mode of measurement, therefore, which depends upon an artisan's capability to make either unit jars or needles equally sensitive cannot be one to be much relied upon. There is, however, a relationship between the motion of the needle and a totally different mode of absolute measurement of the quantity of electricity that may pass in a unit of time, which solves the difficulty now expressed.

The usual apparatus for the decomposition of water by an electrical current is standing here. It is in consequence of completing the wire circuit from this combination of four cells that decomposition takes place. The bubbles are rising regularly and rapidly. Patient