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mouse-ear hawkweed; who has noticed the delicate tinge of crimson that reddens the underside of its outer rayflorets; who has marked the pretty vandyke edge that recalls the five original petals; who has felt the exquisitely graceful effect of the tall scapes, Scattered over with the tiny black glandular down that grows into clusters of mosslike thickness on the imbricated scales of the gummy involucre. Your stock broking gentleman and your sentimental young lady, gazing with a patronizing glance of hasty approval at the works of creation, recognize in a general politely indifferent fashion that daffodils and wild hyacinths, harebells and corn-poppies are "very pretty." It needed no Columbus to discover that continent. But have they ever dreamed of the unnoticed beauty of exquisite detail in the mosses and lichens, the common chickweeds and stag-horn plantains, that everywhere carpet the fair world around them? Do they know aught of the tiny parsley piert that creeps upon the sward with its dainty fern-like foliage; of the close rosettes that press tight to the earth lest any straggling grasses should
oust and overtop them; of the greenflowered knawel that springs from the mossy cart-ruts, one unbroken mass of tiny solid blossoms? All these things the botanist knows well, and to him they form a perpetual fountain of domestic sweets, a natural liturgy of varied tones, an endless source of interest and of pleasure. If these delights thy mind may move, come live with him, and go through a regular course together of De Bary's "Comparative Anatomy of Phanerogams and Ferns.'
But if you ever venture to say again behind my back that the botanist is a dull, dried-up, unimaginative person, who cares nothing for the beauty of the lovely flowers, but goes in only for classification, herbariums, and sesquipedalian Latin names, I will arise and slay you with my hand in another article just as long and every bit as argumentative as this one. Remember in future that a botanist is a man who loves life in all its forms, and brims over visibly with the joy of living. All others are spurious imitations, and should be promptly sent back to Kew Gardens.-Murray's Magazine.
"These be thy suitors, girl. Now take the cup,
And sought the board whereon the cups were ranged
Wildly against all hope. And he, it chanced,
Though no man told him, for their hearts were one.
There he left
In garb of Scythian prince, the palace doors.
Stood cup in hand, and slowly mixed the draught,
THE GENESIS OF THE ELEMENTS.
ALL kinds of matter, say the chemists, whether solid, liquid, or gaseous, are composed of simple substances or elements combined together in an infinite variety of ways. About seventy
such elements are known to exist. They combine either in certain fixed and definite proportions by weight represented by relative numbers, or in proportions which are simple multiples of those numbers. These proportional weights are called atomic weights, because, according to Dalton's well-known atomic hypothesis, they are believed to represent the relative weights of the ultimate atoms of the elements. Every element has its own atom with individual properties and an individual weight, and the element is an aggregate of such atoms, each identical with the others. So that if there are seventy elements, there are seventy kinds of atoms, each kind differing from the other kinds in
weight and other properties. When elements combine to form compounds the ultimate particles of the compounds are clusters of elementary atoms, each atom retaining its individuality. Such clusters are called molecules. Thus the molecule, or ultimate particle of water, is a cluster of three atoms, two hydrogen atoms, each weighing one, and one oxygen atom weighing sixteen. The hydrogen atom is the lightest of all, and is taken as unity. We do not know the absolute weight of an atom of oxygen, but we have good reason to believe that it is sixteen times as heavy as an atom of hydrogen, and so for all the other elements. The atomic weights of the elements vary greatly-from hydrogen I to uranium 240-and appear at the first glance to be merely capricious. They are not, indeed, as far as we know exact whole numbers.
So stands the basis of chemistry as
represented in our text-books, and it is not wonderful that such a basis should have been found unsatisfactory by many thoughtful men. The problem is singularly stimulating to those whose restless minds are constantly searching for new revelations. Why are there seventy elements, or thereabouts-why not more or less? Why do their atoms, if they have atoms, show such diversity and apparent eccentricity in weight and disposition? Is Nature limited on its lowest side by these atoms? and, if not, whence did they arise? How, on any possible development hypothesis, can we account for their formation from nebulous matter or for their obvious individuality? Is it not possible that there may have been in reality but one elemental matter from which our cosmical elements have been formed? and may we not, with the accumulated observations of modern science, hope to obtain some clew to the mystery, some hypothesis not a dream, which shall show us how the evolution may have advanced?
These and similar questions have haunted the minds of chemists since chemistry became a science. Some glimpse of light has from time to time allured us like an ignis fatuus; but no coherent hypothesis was reached, or was indeed possible, until Mr. Crookes, after years of most laborious experimental study and patient thought, found himself, at the last meeting of the British Association, able to suggest one in his address as President of the Chemical Section. Quite recently he has expounded his views anew in a lecture at the Royal Institution, and no one who was present on the latter occasion will forget the eloquence of the lecturer or the brilliance of his experimental illus
with the honest hope of stimulating further study. He asserts nothing, but suggests a great deal.
The first consideration in the study is the relationship between the numbers which are believed to represent the relative weights of the ultimate atoms of elements with the properties of those elements. Dumas was the first to point out that the atomic weights of many analogous elements were related to one another in a manner too definite to be accidental. Thus, to take only one case, the atomic weights of the very similar metals, lithium, sodium, and potassium, were respectively 7, 23, and 39, 23 being the exact mean of the other two. This provoked curiosity, but pointed to no law. But in 1863 a much more important step was taken. English chemist, Mr. John Newlands, whose name will be immortal in the history of science, pointed out that, if the elements are arranged in the order of their atomic weights, they are seen to present a uniform sequence of sevens, so that the eighth resembles the first. Thus the eighth from lithium 7 is sodium 23, and the eighth from sodium is potassium 39. So, again, with fluorine, chlorine, bromine, and iodine, and with oxygen, sulphur, selenium, and tellurium, all groups of very similar elements. This "law of octaves" was received with neglect or derision until the researches of Mendeljeff in Russia and Lothar Meyer in Germany showed its supreme importance. Missing links in the chains of octaves were soon observed, and many have already been filled up by researches stimulated by the new law, which was found to be of far deeper significance than its author could have anticipated. The latest expression of it, the immediate precursor and the inducing cause of the Crookes hypothesis, is due to Professor Emerson Reynolds, of Dublin. Unfortunately it is impossible to give an adequate idea of it without a diagram, but some attempt must be made. Imagine a pendulum swinging and slowly coming to rest. Imagine, further, that the pendulum is steadily sinking downward, and, lastly, imagine that a pencil attached to the weight of the pendulum is drawing a line on a vertical sheet of paper behind. On the paper is a perpendicular line
down the middle. It is evident that the pencil will draw a zigzag line on the paper, right and left of the perpendicular. We shall have, in fact, the pattern which was irreverently described by the wits of the British Association as the Chemical Corset." Now, if the chemical elements are placed on this zigzag line in the order of their atomic weight with an octave on each line from right to left, and another on each line from left to right, we find that the elements in similar position on the zigzag lines, in regard to the central perpendicular line, or, in other words, those that are over one another, are similar in properties in a variety of ways. Without going into details, it may be said that those on any part of the zigzag which are approaching the perpendicular are electro-negative, while those receding from it are electro-positive. All the elements on the right of the perpendicular are dia-magnetic, and of uneven valency, while those on the left are paramagnetic (as iron is), and of even valency. If these words convey no idea to our readers, we can only beg them to believe that they represent very definite differences in physical and chemical properties. Many other well-known analogies and divergencies are shown at a glance in the diagram, which is, indeed, as Mr. Crookes describes it, an interesting and even exciting study for chemists. But what has all this chemical theory and this chemical corset" to do with the genesis of the elements? it may well be asked. We must answer with a most meagre and insufficient sketch of Mr. Crookes's hypothesis, advising all those to whom the exercise of the scientific imagination is a pleasure to study the original. Of course, the whole hypothesis rests on imagination, for no eye can see the events it attempts to depict. But it is no dream, for it rests on a solid basis of observation, and it represents at any rate potential truth. Let it be understood at starting that the pendulum illustration to which further reference must be made, with its right and left swing, and its steady descent, is a symbol typifying two distinct influences, the perpendicular descent a fall of temperature, the lateral swing some exercise of force, possibly, as Mr. Crookes suggests, electricity.
Imagine, then, a universe, or a portion of the universe, without form and void, consisting of nothing but a protyle, to use Mr. Crookes's convenient word, a substance simpler than all elements and prior to them. This condition is antecedent to the formation of suns and planetary bodies which belong to modern history-a mere twenty million years, according to Sir William Thomson. The protyle is at an enormous temperature, which, we presume, means, if heat be motion, in motion of enormous velocity or amplitude. Then begins the cooling, the tendency to equilibrium of temperature, which is the prevalent phenomenon in our cycle of infinite time. As the heat energy of the protyle is lost another energy succeeds it, causing agglomeration of protyle into the small masses, or particles which we call atoms. The first atoms formed are the lightest, the hydrogen atoms. Then in the swing of the cosmic pendulum toward the left, to use the symbol once more, come the positive lithium, glucinum, boron, and carbon atoms, each formed at a definite epoch of the grand development. The pendulum swings back and approaches the perpendicular, and nitrogen, oxygen and fluorine, all negative atoms, are formed at successive stages. The perpendicular line is passed, and the positive sodium, magnesium, aluminium, and silicon atoms are formed in turn, the last forming the apex of the angle and being similar in many respects to carbon, which stands at the first apex. So on until the temperature has fallen so low that the atoms begin to combine with one another, perhaps under the same stimulus of electricity; and in future the agglomeration is not of protyle to protyle, forming atoms, but of atom to atom, forming compounds.
In this manner, or in some manner of which this is symbolical, the elemental forms of matter may have been evolved. Endless questions remain, of course, unsolved; and we cannot expect the writer of such very ancient history to tell us everything. But one paramount question occurs to which Mr. Crookes has devoted the chief labor of many years of his life. Are all the atoms of an element really identical in weight and properties, or is the atomic weight the
mean atomic weight of its atoms? With regard to one element, or to a substance described by that name in our textbooks, the element yttrium, an answer can be given. By thousands of operations, the labor of which can hardly be imagined, Mr. Crookes has apparently proved that this element is really a congeries of elements, nearly, but not quite, identical. To follow the previous illustration, there seems to have been at certain stages a dash of irregularity in the swing of the great pendulum, and the single element got muddled up into a lot of similar and insignificant ones. Several cases of this kind occur in the
series of elements, and perhaps we are apt to push hypothesis too far in our attempt to account for them. But à priori it seems probable that elementary atoms should have not exactly, but only approximately, the same weights. As far as our knowledge goes, nothing outside of mathematics is uniform or perfect. No two seeds, or crystals, or plants, or orbits are quite identical, and why should atoms differ from the rule? As Mr. Crookes puts it, the atom of calcium has a weight of 40, but possibly some atoms weigh 39 and some 41.Saturday Review.
THE CONDUCT OF AGE.
A GOOD part of the world is almost hold that our literature in general often governed by very old men. The Em- misleads commonplace folks from peror of Germany was 90 last month; closely analogous cause,—that all its Von Moltke is 86; Prince Bismarck is most influential portions are due to men 71; M. Grévy, 76; and Mr. Gladstone, of genius, and that men of genius, in 77. Yet the great influence which the their interpretation of life, are very apt old undoubtedly tend to acquire in to misinterpret the experience of those modern times has certainly done noth- who are not only not men of genius at ing to help old people of average calibre all, but who are very apt to be misunto order their life better,-partly, no derstood by men of genius even when doubt, because picked lives of excep- most brilliantly painted by them. The tional vigor are either no models, or history of the world could not, of very unfortunate models for men of or- course, have been either guided or writdinary type; and partly because, even ten except by men of very exceptional if they were to tell us their experience, endowments; but just for that very it would not be of much use to us, in reason, the lessons which have been consequence of the very different con- learned from them are often far less apditions to which men on whose resolves plicable than they are supposed to be to affairs of the greatest moment depend, their humbler fellow-men who have are subjected, very different, we mean, neither their endowments, nor, in genfrom those which surround ordinary eral, that vivid life which usually results people. You could not get much guid- from exceptional endowments. ance as to how to meet the sense of de- what is true of the misleading effect procaying energy from the example of those duced by the teaching of men of high whose energy, even when it has been powers generally on those who have very lessened by age, is twice as great as moderate powers, is equally true of the that of ordinary men of the same age, misleading effect produced on men of or from those who are kept up to their ordinary vigor by watching the old age work by the imperious exigencies of a of men of very exceptional vigor. We position in which very one is looking to are often told that it is a great mistake them for some urgent decision. It to retire early, that the motto of the old would be as wise for a horse to guide should be Cave de resignationibus, and his endeavors in old age by the example so forth. But do the persons who give of the elephant, as for most of us to this advice on the strength of the exguide ourselves in that stage of life by perience of men of unusual strength of the hints which lives such as we have constitution, know what it really means? mentioned might supply. Indeed, we that it means duties half-performed or