families we sum up in the order Decapods; this and kindred orders we sum up in the class Crustacea; and so on until we reach the sub-kingdom of Annulosa.

Division is classification reversed. Thus we divide the animal kingdom into sub-kingdoms, each sub-kingdom into provinces, each province into classes, each class into orders, and so on until we reach the species. With species, classification and division proper end; we have only varieties and individuals left.

Partition is the breaking up of an individual into its component parts. Thus a horse may be partitioned (dissected) into its bony skeleton, muscles, internal organs, outward covering (hair), etc. The species "horse," i. e., the ordinary domestic horse, is classified in one and the same genus with the ass and the zebra.

In loose popular language "divide" and "division" are very frequently used when "partition" is really meant. This is much to be regretted, but the habit can scarcely be overcome now. At all events, the young reader should learn to appreciate thoroughly the fundamental difference between partition and classification-division.

In science, biological or physical, the criteria for classifying and dividing are in nature itself; they may therefore be determined exactly and applied rigorously. In expounding them we must give them as we find them, without altering or abridging. Thus Tait, discussing the available sources of terrestrial energy, classifies them as:

First (potential). 1. Fuel (including wood, coal, zinc, for galvanic battery, etc.). 2. Food of animals. 3. Ordinary water-power. 4. Tidal water-power. Second (kinetic). 1. Winds. 2. Currents (ocean-currents). 3. Hot springs and volcanoes.

He then adds cautiously:

There are other very small sources known to us, exceedingly small; but these I have named include our principal resources.-TAIT: Recent Advances, vii. p. 160.

Having thus classified them, he proceeds to show that

almost all are to be traced back to solar radiation. The conclusion is that terrestrial energy, all but a very small part, is due to the rays of the sun.

52. Cross-Division.—In matters of human invention and in purely spiritual matters rigorous classification, like rigorous definition, becomes difficult and almost impossible. Thus the government of the United States is divided into three factors, legislative, executive, judicial; but, inasmuch as the chief executive, the President, has also, by virtue of his veto, a direct share in law-making, he must be classified-to that extent-with Congress. On the other hand, the Senate, through its right of rejecting presidential appointments, has a share in executing the law. Still further, the Senate and House, through the right of impeachment, are invested with judicial functions.

This overlapping of division-lines is technically called Cross-Division.

The tendency to cross-division exists in all classification which does not rest upon scientific criteria. The young reader can test this for himself. If he is a member of a large school, let him classify all the scholars. He may group them by school classes, in alphabetical or numerical. order; he may group them according to sex, if the school is mixed; he may group them according to scholarship, into poor, fair, good; or into boarders and day-scholars. These several groupings would cross each other.

The reader can further test his ability to classify, by grouping the persons of his acquaintance, the books that he may see in a library, the studies that he may pursue.

GENERAL STATEMENT.

By general statement is here meant the setting forth of a general phenomenon, law, relation, or idea.

53. General Phenomenon.-A very good statement of one is this:

H*

But sound, like light, may be reflected several times in succession, and as the reflected light under these circumstances becomes gradually feebler to the eye, so the successive echoes become gradually feebler to the ear. In mountain regions this repetition and decay of sound produces wonderful and pleasing effects. Visitors to Killarney will remember the fine echo in the Gap of Dunloe. When a trumpet is sounded at the proper place in the gap, the sonorous waves reach the ear in succession after one, two, three, or more reflections from the adjacent cliffs, and thus die away in the sweetest cadences. There is a deep cul-de-sac, called the Ochsenthal, formed by the great cliffs of the Engelhörner, near Rosenlaui, in Switzerland, where the echoes warble in a wonderful manner. The sound of the Alpine horn also rebounding from the rocks of the Wetterhorn or the Jungfrau, is in the first instance heard roughly. But by successive reflections, the notes are rendered more soft and flutelike, the gradual diminution of intensity giving the impression that the source of sound is retreating further and further into the solitudes of ice and snow. TYNDALL: Sound (i.), p. 17.

A remarkable phenomenon of insect-life is this:

This remarkable instinct was first discovered in the Formica (Polyerges) rufescens by Pierre Huber, a better observer even than his celebrated father. This ant is absolutely dependent on its slaves; without their aid, the species would certainly become extinct in a single year. The males and fertile females do no work of any kind, and the workers or sterile females, though most energetic and courageous in capturing slaves, do no other work. They are incapable of making their own nests, or of feeding their own larvæ. When the old nest is found inconvenient, and they have to migrate, it is the slaves which determine the migration, and actually carry their masters in their jaws. So utterly helpless are the masters, that when Huber shut up thirty of them without a slave, but with plenty of the food which they like best, and with their own larvæ and pupa to stimulate them to work, they did nothing; they could not even feed themselves, and many perished of hunger. Huber then introduced a single slave (F. fusca), and she instantly set to work, fed and saved the survivors; made some cells and tended the larvæ, and put all to rights.—DARWIN: Origin of Species, ch. viii. p. 216.

The general phenomena of man's social and spiritual life are far more difficult to state fully and accurately. The difficulty is twofold. First, the facts and data upon

which to generalize are very hard to get. Second, we are apt to approach such questions in a spirit of prejudice.

The historian, for instance, is apt to sympathize with one of two conflicting parties in the past because of its resemblance, real or assumed, to his own party in the present. There is even a third source of error. In writing that is literary rather than scientific the writer is often desirous of writing effectively, as it is called. He seeks to produce by his manner a deep impression on the reader, and in so doing often overstates, sometimes even mis-states, his facts. The following presentation of literary Bohemia in the first half of the eighteenth century is an example:

As every climate has its peculiar diseases, so every walk of life has its peculiar temptations. The literary character, assuredly, has always had its share of faults: vanity, jealousy, morbid sensibility. To these faults were now superadded the faults which are commonly found in men whose livelihood is precarious, and whose principles are exposed to the trial of severe distress. All the vices of the gambler and of the beggar were blended with those of the author. The prizes in the wretched lottery of book-making were scarcely less ruinous than the blanks. If good fortune came, it came in such a manner that it was almost certain to be abused. After months of starvation and despair, a full third night or a well-received dedication filled the pocket of the lean, ragged, unwashed poet with guineas. He hastened to enjoy those luxuries with the images of which his mind had been haunted while he was sleeping amidst the cinders and eating potatoes at the Irish ordinary in Shoe Lane. A week of taverns soon qualified him for another year of night-cellars. Such was the life of Savage, of Boyse, and of a crowd of others. Sometimes blazing in gold-laced hats and waistcoats; sometimes lying in bed because their coats had gone to pieces, or wearing paper cravats because their linen was in pawn; sometimes drinking Champagne and Tokay with Betty Careless; sometimes standing at the window of an eating-house in Porridge Island, to snuff up the scent of what they could not afford to taste: they knew luxury; they knew beggary; but they never knew comfort.-MACAULAY: Boswell's Johnson.

There is undoubtedly much truth in the above. But every thoughtful student will suspect that it is also highly overwrought. Overstatement is, in fact, the prevalent

blemish in Macaulay's method. Matthew Arnold touches upon it lightly but firmly when he says:

I remember hearing Lord Macaulay say, after Wordsworth's death, when subscriptions were being collected to found a memorial of him, that ten years earlier more money could have been raised in Cambridge alone, to do honour to Wordsworth, than was now raised all through the country. Lord Macaulay had, as we know, his own heightened and telling way of putting things, and we must always make allowance for it.-MATTHEW ARNOLD: Preface to Wordsworth's Poems.

The ability to see clearly and state fairly is a matter of sober temperament and philosophic inquiry rather than of mere knowledge. The following passage illustrates Matthew Arnold's own method, in comparison with Macaulay's:

One of these [inconveniences] is, certainly in English public life, the prevalence of cries and catchwords, which are very apt to receive an application, or to be used with an absoluteness, which do not belong to them; and then they tend to narrow our spirit and to hurt our practice. It is good to make a catchword of this sort come down from its stronghold of commonplace, to force it to move about before us in the open country, and to show us its real strength. Such a catchword as this: The state had better leave things alone. One constantly hears that as an absolute maxim; now, as an absolute maxim, it has really no force at al. The absolute maxims are those which carry to man's spirit their own demonstration with them; such propositions as: Duty is the law of life; Man is morally free, and so on. The proposition: The state had better leave things alone, carries no such demonstration with it; it has, therefore, no absolute force; it merely conveys a notion which certain people have generalized from certain facts which have come under their observation, and which, by a natural vice of the human mind, they are then prone to apply absolutely. Some things the state had better leave alone, others it had better not. Is this particular thing one of these, or one of those?-that, as to any particular thing, is the right question. -MATTHEW ARNOLD: A French Eton, p. 472.

See also A priori, § 74.

The following is in a lighter vein :

At almost every step in life we meet with young men . . . for whom we anticipate wonderful things, but of whom, even after much and careful inquiry, we never happen to hear another word. The effervescence