Page images

and was universally hailed as a deliverer.* They compare the domestic squabbles of the Carthaginians, when their very existence was threatened from without, to our scruples about the Royal conscience, and our fears about the established Church, when the enemy is thundering at our gates. In their mind, there is no surer prognostic of our doom, than the strange policy of suffering our internal sores to fester and imposthumate,-of distilling immunities, drop by drop, to a clamorous and discontented people, as if it were actually our policy to quicken their relish, and to embitter their resentments.

Overweening as those anticipations are, it is lamentable to think how broad a foundation they have in fact. We have a fleet, in


deed, and a population very different from that of Carthage. Ireland is a vital member of our empire, and not a distant dependency like Spain. A dreadful crisis, we have no doubt, is preparing for us; and how are we prepared to meet it? We have substantially means for a noble struggle-we think, for a sure defence; but they are locked up by prejudice, by faction, and by base and shortsighted self-interest. The near approach of the most tremendous danger which ever threatened any nation in the annals of the world, has made no change in our feelings, nor, so far as we can observe, in our policy. The same want of system, the same blustering series of paltry expedients,-the same headstrong rashness and ignorant confidence, which have proved the ruin of the kingdoms around us,-are still manifest, we are afraid, among ourselves. Is there any reasonable creature who. can hear the name of Ireland pronounced, and think what may be its situation before another year has gone over us, without consternation and dismay? Yet no step is taken to allay the discontents of the Irish; and court-interest, and place and preferment, are still sought after by the same system of mean compli ance and angry recrimination, by which court affairs may be well enough conducted in times of security and peace. At such a season, we should disdain to think of party, or to waste a word upon the comparative merits of ministers, or of their opponents. We want to see the real strength and resources of the nation applied to the task of its deliverance; and we care not by what hands this great object may be effected. The place of a British minister, indeed, does not to us, at this moment, appear an object of attraction or envy. Even to the most powerful ta

G g 3


* There is a melancholy exactitude in some points of this comparison. Those who require to feel the full force of the example, will do well to consult the 6th chapter, 10th book of Polybius, wherein he narrates the alarms of the Carthaginians, and the conduct of the Spaniards, on the approach of their invaders.

lents and the most exalted virtues, it must be environed with depressing anxieties, and tremendous responsibility. Incapacity, indeed, is generally insensible of the dangers which it is sure to enhance; and selfishness is, for the most part, as rash as it is ultimately cowardly.

Of peace, we are afraid, it is now useless to say any thing. The time for that sage and cautious policy is probably irrevocably passed over. It might have saved Europe, long after the consequences of the opposite system had become manifest: but Europe is lost; and the condition of England is no longer what it was. Our enemy is not likely to grant us peace,—and it is more than doubtful if we could accept of any terms which he would offer. We hope, however, that no one is still found so insane as to expect that we shall force him to an accommodation by the commercial distress of his dominions. He does not want commerce. His armies suffer nothing from that distress; and he cares nothing for the discontents or privations of the millions he has reduced to slavery. This weapon, at all events, will unquestionably recoil on ourselves; and the eagerness with which the enemy has taken advantage of our decrees, to seal up hermetically almost every port on the Continent, demonstrates how truly those decrees have actually seconded his designs.

When we look stedfastly on the power which we have endeavoured to describe, and on the measures and the councils by which it has hitherto been opposed, we confess that we cannot be sanguine; and that we cannot be satisfied. We shall be called Jacobins and friends of Bonaparte, we suppose, for expressing these sentiments. This is to us a matter of perfect indifference. We do our duty in making public the facts and the impressions to which we think it of importance that the attention of the country should be directed; and are too much occupied with the honest anxiety excited by these statements, even to be conscious of the contempt with which, at another time, we might treat such



Electro-Chemical Researches on the Decomposition of the Earths; with Observations on the Metals obtained from the Alkaline Earths, and on the Amalgam procured from Ammonia. By Humphrey Davy, Efq. Sec. R. S. M. R. I. A. (From the Philofophical Tranfactions for 1808, Part II.)

WE had the fatisfaction of introducing to the knowledge of

our readers, in two the ingenious and elaborate fries of experiments by which Mr Davy was led to the


[ocr errors]

discovery of fome new properties of electricity, and, by their means, to the decompofition of the fixed alkalis. Thefe difcoveries, by far the most striking for their novelty, and the most important for the further views which they open, of any that have been made fince the new theory was established, have attracted the notice of chemical inquirers in this and in other countries: and, although the miferable ftate of public affairs has prevented them from exciting fo general an intereft, and producing as large an harvest as they must have done had they fallen on happier times, a confiderable progress has nevertheless been made, both by the difcoverer himself and those whom his successful researches set in motion, even during the short interval which has elapfed fince we last brought the fubject under review. The chemifts of France have most unexpectedly found that the decompofition of the alkalis is much easier than was at first imagined, and that it may be effected by other ways than the electric agency. The Swedish philofophers have accomplished a discovery yet more furprising-perhaps, of all the late refults, the most unlooked for-the metallic nature of ammonia, and confequently of the two gafes which conftitute that alkali. Mr Davy has, in the mean while, pursued his brilliant courfe of investigation with almost uninterrupted fuccefs,and has added, to the knowledge which he formerly gave us of the fixed alkalis, that of the principal earths. The decompofition of thefe bodies being attended with greater difficulty, and requiring a more complicated and powerful apparatus than is neceffary for the refolution of the alkalis, our author has not brought all his experiments to what he deems the utmoft pitch of accuracy and precifion. But, because he fees no profpect of foon obtaining the requifite machinery, he moft wifely and meritorioufly gives them to the world in their present state, preferring,' to ufe his own expreffions, the imputation of having published unfinished labours, to that of having concealed any new facts from the scientific world, which may tend to affift the progrefs of chemical knowledge. We e certainly do not mean to detract any thing from the praises due to fuch difinterested conduct, when we fay that Mr Davy can abundantly afford to fhare his ample revenue of difcoveries with his lefs fortunate brethren.

The galvanic battery being applied to lime, ftrontites and barytes, in the fame manner as it had been to the alkalis, a decompofition was obferved to take place. Gas was evolved, and metallic globules were produced in contact with the negative wires. But this procefs could not be completed fo as to fhow the nature of the products in a fatisfactory manner. Potaflium (the basis of potaíh) being heated in contact with alkaline earths, feemed to act upon them; but this experiment did not appear to effect their decompo

Gg 4


fition. Mixtures of potash with the fame earths, acted upon by the galvanic battery, fhowed figns of decompofition. Metallic bodies were produced less fusible than potaffium, burning immediately after their formation, and reproducing the mixture of alkali and earth employed. But much more fatisfactory refults were obtained by expofing to the battery mixtures of the earths and metallic oxides. The prefence of the metal greatly affifts the operation; and an alloy is produced at the negative point, confifting of the metal reduced, and the metal of the earth likewife freed from its oxygen. The alloy, when expofed to air or water, reproduces the earth by oxygenation; but ftill, from the proneness of these new metals to unite with the wires of the battery, and to burn almoft as foon as they were formed, fufficient quantities could not be obtained for the purposes of examination; and our author was engaged in repeating and varying his attempts to effect the decompofition more eafily, when he received a letter from Profeffor Berzelius of Stockholm, ftating that he and Dr Pontin had completed the process with great eafe, by exhibiting negatively electrified mercury to barytes and lime. Mr Davy repeated this process with fignal fuccefs; and he does not withhold from it the praise which its ingenuity deferves. He applied it likewise to strontites and magnefia; with the former, it fucceeded more easily than with the latter :-but, in all these cases, an amalgam is formed of mercury with the metallic bafis of the earth; and this amalgam again gives earth and mercury, when expofed to the air or to the action of water. The procefs he found to be greatly facilitated by ufing muriates or fulphates of the earths, inftead of the fimple earths.

By combining this method of the Swedish chemifts with his own, formerly defcribed, Mr Davy obtained, in confiderable quantities, the amalgams of mercury and the bases of the earths. He placed on platina a mixture of the earth and oxide of mercury;in this mixture he made a cavity, wherein he poured a globule of mercury, and, covering the globule with a film of naphtha, he made the platina pofitive, and the globule negative :--it was speedily converted into the amalgam required. This was expofed to ftrong heat in a glafs tube, in order to expel the mercury; but our author fcarcely ventures to affert that he ever completely fucceeded in feparating the two fubftances. He seems to have come nearest his object in the cafe of barytes; and to have failed most with lime. Of none of these metallic bafes did he obtain a fufficient quantity for a fatisfactory examination of their physical and chemical properties. They feem in general to resemble one another; they are folid, except at high temperatures ;-they are much heavier than water,-have a high metallic luftre, refembling



that of filver; and require a confiderable force to flatten them. When exposed to oxygen, they abforb it greedily, and return to their native earths refpectively. Thefe new fubftances,' fays

Mr Davy, will demand names; and, on the fame principles as I have named the bafes of the fixed alkalies, potaffium and fodium, I fhall venture to denominate the metals from the alkaline earths barium, strontium, calcium, and magnium. The laft of these words is undoubtedly objectionable; but magnesium has been already applied to metallic manganefe, and would confequently have been an equivocal term. ’

Our author next directed his inquiries to the conftitution of other earthy bodies,-filex, alumine, zircone, and glucine, but with much less fuccefs. He purfued his experiments indeed with unremitting perfeverance, and with his ufual ingenuity; but, although he has related them at some length, and although the recital is highly valuable to future experimenters, we fhall not follow it any further than to add, that there feems reason to infer that the earths in queftion have, like the alkaline earths, metallic bafes; and we are confident Mr Davy's future refearches will both establish this point as fatisfactorily as he has demonftrated the other, and will give us the fame knowledge of the propertiesof the new bases.

The last object of research was fuggefted to our author by a very important experiment of the Swedish chemifts, formerly mentioned. These ingenious philofophers found, that mercury, placed in contact with a folution of ammonia, and negatively electrified, expands in volume, and becomes a foft folid;-that this folid, on exposure to air, abforbs oxygen, and reproduces ammonia and mercury;-that water is decompounded by it, giving out hydrogen gas, and leaving solution of ammonia and mercury. The conclufion naturally drawn from this curious experiment was, that ammonia is, as Mr Davy himself had formerly fuppofed, an oxide with a double bafis, compofed of hydrogen and nitrogen; but it feems to show alfo, that this double bafis poffeffes metallic properties. So unexpected a light could not fail to attract the quick and difcerning eyes of our author; and he loft no time in purfuing the track into which it plainly led him. His first repetition of the Swedish experiment fuggefted a very material improvement on it-the fubftitution of neutral falt of ammonia, whereby the deoxygenation and amalgamation are effected in the nafcent ftate of that alkali, and are, confequently, more eafily performed. His process was thus the fame with that formerly defcribed for deoxygenating the earths; only, that instead of fulphates or muriates of thofe earths, he exhibited muriate of ammonia. • The action,' fays he, of the quickfilver on the falt was immediate.

« PreviousContinue »