are set down in the order of the atomic weights of the elements symbolized,-save only in the case of tellurium, of which the symbol is placed immediately above, instead of below that of iodine, and of which the atomic weight may not improbably have been somewhat over-estimated. And violating the order of numerical seriation in this small particular only, it is remarkable with what facility the symbols of the forty-six elements may be arranged in parallel lines and columns, corresponding to a natural classification of the elements themselves into analogous groups and series. Indeed, a study of the entire number of elements at present known, would seem to indicate that they are one and all associated with each other by a certain community of relationship; of which the well-known gradation and parallelism in properties and atomic weights, of the members of the alkali and earth-alkali, and of the halogen and oxygen families of elements afford only the most prominent examples.

Taking the second line of the Table as an illustration, it is observable that the seven metals symbolized thereon are distinguished from all the others by their common property of forming one chloride only, and that a di-chloride; further, that the metals figuring in the unevennumbered columns of this line, namely, magnesium 24, zinc 65, and cadmium 112, are permanent in the air, are volatilizable in the direct, and basylous in the inverse order of their atomic weights, and are otherwise specially associated with one another; while the similarly associated metals of the alternate or even-numbered columns, namely, calcium 40, strontium 87·5, and barium 137, are quickly oxidizable in the air, are practically non-volatile, and are basylous in the direct instead of in the inverse order of their atomic weights; and similarly, on the other lines of the Table, the elements symbolized are divisible into sub-groups, according to their odd and even positions respectively.

Such being the relationship of the elements placed on the same line, the relationship of those in the same column is of a different kind. Taking the third and seventh columns by way of illustration, it is observable that the consecutive elements in each column have closely consecutive atomic numbers; that the element on the first line forms a mono-chloride; that on the second line, a di-chloride; that on the third line, a tri-chloride; and that on the fourth line, a tetrachloride; while those on the fifth, sixth, and seventh lines form oxides or oxichlorides, corresponding to a penta-, hexa-, and hepta-chloride respectively.

By reason of its atomic weight, 113.5, indium is observed to figure on the third line and seventh column of the above Table; but its position among the elements is better recognizable by a glance at the Table below, containing a portion only of the preceding one, supplemented by an additional column of elements of higher atomic weight than any of those included previously.

In respect of its atomic weight, then, triad indium occupies a position exactly intermediate between the positions of diad cadmium and tetrad tin, to both of which metals it presents a most marked re

semblance in properties. They all three have the same extreme degree of fusibility, and much the same oxidizability and reducibility. Their sulphides are alike characterized by a yellow colour, that of cadmium, Cd S, being neutral; that of tin, Sn S, being acidulous; and that of indium, In, S,, being strictly intermediate.

Viewed in another aspect, triad indium occupies a position intermediate between the positions of its remote triad congeners, aluminium and thallium. The mean atomic weight of the three metals being 114 3, the atomic weight of indium is 113.5. The mean specific gravity of the three metals being 7.3, the specific gravity of indium is 7.4. And in respect of purely chemical habitudes, hydrated alumina and hydrated india might easily be mistaken for one another. It is interesting, moreover, to remark that the last-discovered two metals indium and thallium-discovered, it will be remembered, by the same process, that of spectrum analysis-should bear to one another much the same sort of relation that is borne to one another by the jovian and saturnine metals of the alchemical or even pre-alchemical era. Just, for example, as the unstable and least-known chloride of lead, Pb CL, corresponds to the stable chloride of tin, Sn Cl, so does the unstable and least-known chloride of thallium, Ti Cl,, correspond to the stable, and as yet only known, chloride of indium, In Cl,, as suggested, indeed, by the lecturer some six or seven years ago.

The study of such relationships necessarily suggests many inquiries. Arranging the entire fifty-eight elements of which the atomic weights are known, in a table similar to the preceding one for the forty-six elements having atomic weights not exceeding 137, some twenty or five-and-twenty new elements would be required to fill up the gaps in the different series; but why should not new elements be discovered having atomic weights as much above that of uranium, 240, as its atomic weight is above that of barium, 137?

Again, does it seem probable that bodies capable of being arranged in such a well-marked numerical series, are really elementary and mutually independent; or is it more likely that the gradation of properties and atomic numbers manifested by these bodies, depends on their possession of different increments of common material?

X

y

May it not be that the numerical ratio between the atomic numbers of proximate elements, = approximatively, is really absolute; and that it will hereafter be proved to be so by a better determination of atomic weights. Seeing that a short time back, cæsium with the atomic weight 133, and rubidium with the atomic weight 85, both occurred as unrecognized impurities in potassium with its atomic weight 39, who shall answer for the absolute accuracy of even the best established of our present atomic weights?

Again, the mean difference in atomic weight between consecutive analogous elements, is, in the case of the nine following pairs of elements, lithium and sodium, glucinum and magnesium, boron and aluminum, carbon and silicon, nitrogen and phosphorus, oxygen and sulphur, fluorine and chlorine, sodium and potassium, magnesium and calcium, 16.1; the lowest difference being 15, and the highest 17. The mean difference in the case of the four following similar pairs of proximate elements, phosphorus and vanadium, sulphur and chromium, chlorine and manganese, arsenic and niobium, is 19.25; the lowest difference being 19, and the highest 20 5. Lastly, the mean difference in the case of the seven following similar pairs of proximate elements, calcium and zinc, vanadium and arsenic, manganese and bromine, rubidium and silver, strontium and cadmium, silver and cæsium, tantalum and bismuth, is 24 6; the lowest and highest differences, even in the case of these elements of such high atomic weight, being 23 and 26 respectively. Are these differences in atomic weight only approximatively, or are they indeed absolutely, 16, 20, and 24 respectively; and if so, why should the numerical difference between proximate associated elements be 16 in one set of cases, 20 in another set, and 24 in a third?

[W. O.]

WEEKLY EVENING MEETING,

Friday, January 26, 1872.

SIR HENRY HOLLAND, Bart. M.D. D.C.L. F.R.S. President, in the Chair.

HENRY EDWARD ARCHBISHOP OF WESTMINSTER,

On the Dæmon of Socrates.

Ar the outset I must plead guilty to a misnomer, for which, however, I am not responsible. It has become a tradition to speak of the Dæmon of Socrates; but I hope to show that the term is without warrant and incorrect.

The Dæmon of Socrates has been treated so often, and by so many authors, historians, philosophers, and critics, both in classical and Christian times, that I, at least, cannot hope to say anything new upon it. I may, however, review the judgments of others, and then offer what seems to me to be the true interpretation of this singular fact in the history of philosophy.

It will, I think, be found to be no mere intellectual eccentricity, no mere superstition, still less an unmeaning record of Greck history, but a fact in the psychology of the greatest philosophical mind of the ancient world, full of significance for us, and throwing much light upon the analysis of our moral nature.

The life of Socrates extended over a tract of seventy years, that is from 469 to 400 B.C., and embraced the most critical and splendid period of Athenian history. . . . . In the midst of all the splendours of imperial greatness, intellectual culture, excessive refinement, luxurious self-indulgence, public and private immorality, Socrates arose as a cross-questioner of men, a seeker after moral truth, an example and a teacher of temperance and justice. There is something majestic and melancholy in his account of himself, and of his mission, as he declared it in his Apology before his judges. He was accused by Meletus and Anytus of corrupting the youth of Athens by philosophical paradoxes, and of introducing new gods, or of denying all gods. In answer he spoke as follows:

"If you should say to me, O Socrates, we will not believe Anytus. We will

let you off; but on this condition, that you no longer go on with this questioning and philosophizing; and if you should be caught again doing this, you shall

die.'

"If, as I said, you should acquit me on these conditions, I should say to you,

O men of Athens, I reverence you and I love you, but I shall obey God rather than you. As long as I breathe, and am able, I shall not cease to philosophize, and to exhort you, and to demonstrate (the truth) to whomsoever among you I may light upon, saying, in my accustomed words, 'How is it, O best of men, that you, being an Athenian, and of a city the greatest and noblest for wisdom and power, are not ashamed to be careful of money, studying how you can make the most of it; and of glory also and of honour: but of prudence, and truth, and of the soul, how you may make the best of that, have neither care nor thought?' And this I will do, to young and old, whomsoever I may meet; both to alien and citizen, and, above all, to the men of this city, inasmuch as you are nearer to me in kindred. For this is the command of God, as you well know; and I think that no greater good ever yet came to the State, than this service which I render to God. For I go about doing nothing else than to persuade you, both young and old, to be careful in the first place neither of the body, nor of money, nor of anything so earnestly as of the soul, how you may make it as perfect as possible. I tell you that virtue does not spring from money, but that from virtue money springs, and all other goods of man, both to the individual and to the commonwealth. If, then, to teach these things be to destroy our young men, that would be mischievous in me indeed. But if anyone should say I teach anything other than these truths, he speaks falsely. Moreover, I say, O Athenians, whether you believe Anytus or not, and whether you let me go or not, I shall never do anything else, even though I were to die many times.*

"Do not clamour, O Athenians, but abide by the request I made to you, that is, not to clamour at what I am saying, but to hear me. For you will be benefited, I believe, by hearing me. I am about to say to you some things at which, perhaps, you will cry out; but I pray you not to do so. For you know well, if you should kill me, being such a one as I say I am, you will not hurt me so much as you will hurt yourselves. Neither Meletus nor Anytus can any way hurt me. This cannot be. For I do not think that it is ever permitted that a better man should be hurt by a worse. Perhaps, indeed, he may kill him or drive him into exile, or disfranchise him; and these things perhaps he and others may think to be great evils. But I do not think so: much rather the doing that which he (Meletus) is now about-the laying hands on a man to kill him unjustly, is a great evil. But, O Athenians, I am far from making now a defence for myself, as some may think; [I am making it] in your behalf; lest by condemning me you should in anything offend in the matter of this gift which God has given you. For if you should kill me, you will not easily find another man like me, who, to speak in a comic way, is so precisely adapted by God to the State; which is like a horse, large and well-bred, but from its very size sluggish, and needing to be roused by some gad-fly. For so it seems to me, that the God has applied me, such as I am, to the State, that I may never cease to rouse you, and persuade and shame everyone, fastening upon you everywhere all day long. Such another will not easily come to you, O men of Athens; and if you will listen to me, you will spare me. But perhaps, as those who awake in anger when they are stung, you will, at the instigation of Anytus, kill me at once with a slap; then you will end the rest of your life in sleep, unless God shall send some other gad-fly to be mindful of you. But that I am such a one, given by God to the State, you may know from this fact. It is not like the way of men that I, now for so many years, should have disregarded all my own concerns and should have endured the neglect of my own domestic affairs, and should have been ever busied about your interests; going about to each of you privately, as a father or an elder brother, persuading you to be careful of virtue. If indeed I had derived any enjoyment from these things, and for these exhortations had received any reward, there would have been some reason in it. But now you yourselves see that the accusers, charging me as they do, without shame, of other things, of this at least have not been able to bring a witness against me; as if I had ever either exacted or asked

*Apologia Socratis, s. 17. Platonis Opp., vol. i. 114. Ed. Stallbaum, Gothæ, 1858.