in the upper air, and comparatively deficient near the earth, whereby the balance of tension, or its equilibrium, must become more or less disturbed according as evaporation varies at the surface. In this way such continuous fluxions of heat into the higher regions, and its redundant state there, generates and sustains the return currents of the element from above towards the lower clouds and the earth, which elemental movements constitute the electrical currents, such as are shown by electrometers. The diurnal variations of these currents arise from the differing rates of evaporation in the day and night. The ordinary course of these elemental fluxions apply to the common invisible currents, but, in like manner, when the mutations are excessive, they will account for the more rapid and violent electrical phenomena, constituting the thunder storms and lightnings, which so often occur within the tropics, and sometimes in our latitudes when evaporation is very rapid.* In fine, all of the corruscations, or vivid transits of the said element to restore its disturbed equilibrium are to be taken as constituting what we call the electrical and magnetic currents-as before said. Since we find that mechanical forces are exerted, as in telegraphy, &c., both by the electrical and magnetic currents, their materiality is clearly proved, for such action can only be by contact of natural bodies; and by conjoint action they are shown to be merely two conditions of one and the same element, just as the mingled and alternate action of light and heat show them to be but two forms of one element. The amounts of latent heat in different bodies may be here passed by, but one other case of latent heat in aqueous

"The phenomena of aqueous meteors, such as rain, fog, and dew depend upon the known relations of heat and water; electricity appears to be a consequent, rather than an agent, in the formation and decomposition of clouds, or if a necessary agent, it is equally so in the boiling of water in our houses or the drying of piece goods in a stove."-Dalton: Memoirs Literary and Philosophical Society, vol. 4, 2nd series, page 123.

vapour should be noticed, viz. the heat evolved in respiration. Beneficent nature always provides for her own wants in excess. The carbonic acid formed in the lungs gives out the needful heat to keep up the temperature of the warmblooded animals, and the excess of heat so evolved is taken up by the water converted into steam and which is carried away in breathing. Now, if the whole of the heat so absorbed in the steam were to remain as sensible heat in it, the 940° held latent therein would at once produce a temperature quite destructive of the living textures and would of course extinguish life. Thus we see another of the sublime laws of Providence is made to rest on these mutatations of the imponderable elements. Little need here be said concerning radiating heat as apart from that of light, yet one instance may be cited, viz., the experiment of suspending a thermometer from the top of a glass-receiver on the table of an air-pump, then by rapidly drawing out the air the temperature will fall to or near the freezing point, but the mercury will again slowly rise till it reaches the temperature of the room; but as the thermometer (attached by a non-conductor of heat) is quite isolated in a vacuum, how can the heat reach and re-enter the bulb, except it be by radiating from the external warm air through the glass and the vacuum, and thus restoring the equal temperature inside and outside of the receiver. This process is of the same kind as that of heat radiating from a common fire-place to warm a room.

In my "Notes on Heat in Relation to Atmospherical phenomena," read at the Society, February 9th, 1853, besides adducing reason for assuming that all electrical and magnetical phenomena are simple consequences of the mutations of one pervading element, I have therein shown how most of the great aerial and oceanic currents may be traced to the acting forces generated by the mutations of heat, when they are excited in conjunction with those of gravity.

Now, since all philosophers recognise the presence everywhere of the three elements of light, electricity, and magnetism, as also the fact of their reciprocal interchanges of form, as exhibited in phenomena; and as we find, also, the general admission of "an elastic ether" in space, it would seem far more in harmony with "the simplicity of nature's laws" to ascribe those known forms of "the imponderable elements" to the mutations of one than to the existence, in space, of four distinct elements. I have accordingly aimed to show that each of the known conditions of imponderable matter are traceable to the mutations of the one pervading element, and, for the reasons before stated, I call this elemental or neutral heat.

"Researches on Di-Methyl," by WM. H. DARLING, Dalton Scholar in the Laboratory of Owens College. Communicated by Professor H. E. Roscoe, Ph.D., F.R.S.

The synthesis of carbon compounds forms perhaps the most important and interesting branch of modern chemical enquiry. The most recent developments of these synthetical processes are the now well ascertained facts of the dependence of the chemical properties of the molecule, upon the position of the individual atoms of which that molecule is built up.

Any isomeric modifications of the saturated monovalent compounds containing one or two atoms of carbon can only be explained by the existence of a difference between the four combining powers of each carbon atom, whilst in the tri-carbon and higher series isomerism indicates the difference in the power of combination existing between the end and the middle carbon atoms of the chain.

From Frankland's original observations concerning the difference between the action of chlorine on the so-called

di-methyl CH obtained by the electrolysis of an alkaline

CH},obtained

acetate, and on the hydride of ethyl obtained from ethyl compounds, the existence of a difference in the four combining powers of a carbon atom was rendered probable.

The subsequent researches of Schorlemmer have, however, proved that only one hydrocarbon of the formula C.H, exists, inasmuch as he succeeded in preparing ethyl chloride from the hydrocarbon di-methyl CH}, obtained by the electrolytic decomposition of an alkaline acetate (Proc. R. Soc., XIII., 225); as well as from ethyl hydride, obtained from ethyl compounds.—(J. Chem. Soc., N.S., II. 262.)

It appeared of great interest to repeat this synthesis, and to prepare the chloride in larger quantity, from which to prepare ethyl compounds and ascertain their chemical and physical properties.

At the request of Mr. Schorlemmer, I undertook this investigation. I take this opportunity to express my thanks to that gentleman, and also to Professor Roscoe for the kind assistance rendered to me throughout this research.

I prepared the di-methyl by the electrolytic decomposition of acetate of potash, according to the process described by Kolbe. The gas, evolved from a platinum plate contained in a porous cell, was passed first through a solution of caustic potash, to absorb the carbonic acid, afterwards through nordhausen acid, and over pumice stone moistened with oil of vitriol, to free it from a trace of oxide of methyl or hydrocarbon absorbable by this acid, and finally through a solution of caustic potash, to absorb acid fumes, any carbonic acid which had escaped the first wash bottle, or traces of sulphurous acid. The gas thus prepared had a very slight odour, it burnt with a non-luminous flame.

The following analysis of it is according to Bunsen's method:

This gas, treated with an equal volume of chlorine, was exposed to the diffused sun-light, after allowing time for the two gases to mix until nearly colourless, and completed by means of direct sun-light when quite colourless. The bottle was opened under warm water: the hydrochloric acid was absorbed equal to half the capacity of the bottle. The remainder of the gaseous contents not absorbed were displaced by warm water into a receiver, in which a few pieces of stick potash were placed, surrounded by a freezing mixture of salt and ice-a colourless, volatile liquid was condensed.* One hundred grammes of chloride were prepared by the repetition of this process. This first product was separated by distillation into two parts, one which distilled below 30° C., and the other above 30° C. On still further fractionating the first distillate, a portion was obtained boiling at 11 -13° C., whose Sp. Gr. was 0.9253 at 0° C. Pierre found the specific gravity of ethyl chloride to be 0.9241 at the same temperature.

The chloride boiling below 30° C. gave, on heating in

If the gas or the chlorine was not pure, being mixed with air, very little or no liquid was condensed, being carried off by the current. The same was observed by Mr. Schorlemmer. This will probably account for Frankland's observation that no liquid was condensed at -18° C.