abandon the attempt to carry out an arrangement according to the natural classification of the sciences, and form comprehensive practical groups, we shall be continually perplexed by the occurrence of intermediate cases, and opinions will differ ad infinitum as to the details. If, to avoid the difficulty about Westminster Abbey, we form a class of books devoted to the History of Buildings, the question will then arise whether Stonehenge is a building, and if so, whether, cromlechs, mounds, or even monoliths are so. At the other end of the scale we shall be uncertain whether to include under the class History of Buildings, lighthouses, monuments, bridges, &c. In regard to purely literary works, rigorous classification is still less possible. The very same work may partake of the nature of poetry, biography, history, philosophy, or if we form a comprehensive class of Belles-Lettres, nobody can say exactly what does or does not come under the term.

My own experience entirely bears out the opinion of the late Professor De Morgan, that classification according to the name of the author is the only one practicable in a large library, and this method has been admirably carried out in the great Catalogue of the British Museum. The name of the author is the most precise circumstance concerning a book, which usually dwells in the memory. It is more nearly a characteristic of the book than anything else. In an alphabetical arrangement we have an exhaustive classification, including a place for every possible name. The following remarks of De Morgan seem therefore to be entirely correct. From much, almost daily use, of catalogues for many years, I am perfectly satisfied that a classed catalogue is more difficult to use than to make. It is one man's theory of the subdivision of knowledge, and the chances are against its suiting any other man. Even if all doubtful works were entered under several

d'Philosophical Magazine,' 3rd Series (1845), vol. xxvi. p. 522.

different heads, the frontier of the dubious region would itself be a mere matter of doubt. I never turn from a classed catalogue to an alphabetical one without a feeling of relief and security. With the latter I can always, by taking proper pains, make a library yield its utmost ; with the former I can never be satisfied that I have taken proper pains, until I have made it, in fact, as many different catalogues as there are different headings, with separate trouble for each. Those to whom bibliographical research is familiar, know that they have much more frequently to hunt an author than a subject: they know also that in searching for a subject, it is never safe to take another person's view, however good, of the limits of that subject with reference to their own particular purposes.'

It is often very desirable, however, that an alphabetical name catalogue should be accompanied by a subordinate subject catalogue, but in this case no attempt should be made to devise a theoretically complete classification. Every principal subject treated in a book should be entered separately in an alphabetical list, under the name most likely to occur to the searcher, or under several names. This method was partially carried out in Watts's valuable 'Bibliotheca Britannica,' but it was perfectly applied in the admirable subject index to the British Catalogue of Books,' and equally well in the 'Catalogue of the Manchester Free Library at Campfield,' this latter being the most perfect model of a printed catalogue with which I am acquainted. The public Catalogue of the British Museum is arranged as far as possible according to the alphabetical order of the author's names, but in writing the titles for this catalogue several copies are simultaneously produced by a manifold writer, so that a catalogue according to the order of the books on the shelves, and another according to the first words of the title-page, are created by a mere re

arrangement of the spare copies. In the English Cyclopædia' it is suggested that twenty copies of the book titles might readily have been utilized in forming additional catalogues, arranged according to the place of publication, the language of the book, the general nature of the subject, and so forthe.

It will hardly be a digression to point out the enormous saving of labour, or, what comes to the same thing, the enormous increase in our available knowledge, both literary and scientific, which arises from the formation of extensive indices. The 'State Papers,' containing the whole history of the nation, were practically sealed to literary inquirers until the Government undertook the task of calendaring and indexing them. The British Museum Catalogue is another national work, of which the importance in advancing knowledge cannot be overrated. The Royal Society is accomplishing a work of world-wide importance, in publishing a complete catalogue of memoirs upon physical science. The time will perhaps come when our views upon this subject will be extended, and either Government or some public society will undertake the systematic cataloguing and indexing of masses of historical and scientific information which are now almost closed against inquiry.

Classification in the Biological Sciences.

The great generalizations established in the works of Herbert Spencer and Charles Darwin have thrown great light upon many other sciences, and, strange as it may seem to say so, they have removed several difficulties out of the way of the logician. The subject of classification has long been studied in almost exclusive reference to the

e

English Cyclopædia,' 'Arts and Sciences,' vol. v. p. 233.

arrangement of the various kinds of animals and plants. Systematic Botany and Zoology have been commonly known as the Classificatory Sciences, and scientific men seemed to suppose that the methods of arrangement, which we e suitable for living creatures, must be the best for all other classes of objects. Several mineralogists, especially Mohs, have attempted to arrange minerals in genera and species, just as if they had been animals capable of reproducing their kind with variations, and thus having relatives like distant cousins.

It is highly remarkable that this confusion of ideas between the relationship of living forms and the logical relationship of things in general prevailed from the earliest times, as manifested in the etymology of words. We familiarly speak of a kind of things meaning a class of things, and the kind consists of those things which are akin, or come of the same race. It is even believed by some etymologists that second means other kind, the Latin suffix cund being thus regarded as cognate with kind f. Similarly when Socrates and his followers wanted a name for a class regarded in a philosophical light, they again adopted the analogy in question, and called it a yevos, or race, the root yev- being distinctly connected with the notion of generation.

So long as the species of plants and animals were believed to proceed from distinct and unconnected acts of Creation, the multitudinous points of resemblance and difference which they present, possessed a simply logical character, and might be treated as a guide to the classification of other objects generally. But when once we come to regard these resemblances as purely hereditary in their origin, we see that the sciences of systematic Botany and Zoology have a special character of their There is no reason whatever to suppose that the f Vernon, Anglo-Saxon Guide,' p. 68.

own.

same kind of natural classification which is best in biology will apply also in mineralogy, in chemistry, or in astronomy. The universal logical principles which underlie all classifications are of course the same in natural history as in the sciences of brute matter, but the special logical resemblances which arise from the relation of parent and offspring will not be found to prevail between different kinds of crystals or mineral bodies.

The genealogical view of the mutual relations of animals and plants leads us to discard all notions of any regular progression of living forms, or any theory as to their symmetrical relations. It was at one time a great question whether the ultimate scheme of natural classification would prove to be in a simple line, or a circle, or a combination of circles. Macleay's once celebrated system. was a circular one, and each class-circle was composed of five order-circles, each of which was composed again of five tribe-circles, and so on, the subdivision being at each step into five minor circles. Thus he held that in the animal kingdom there were five sub-kingdoms-the Vertebrata, Annulosa, Radiata, Acrita, and Mollusca. Each of these was again divided into five-the Vertebrata consisting of Mammalia, Reptilia, Pisces, Amphibia, and Avess. It is quite evident that in any such symmetrical system the animals were made to suit themselves to the classes instead of the classes being suited to the animals.

We now perceive that the ultimate system will be an almost infinitely extended genealogical tree, which will be capable of representation by lines on a plane surface of sufficient extent. But there is not the least reason to suppose that this tree will have a symmetrical form. Some branches of it would be immensely developed compared with others. In some cases a form may have pro

g Swainson,' Treatise on the Geography and Classification of Animals, 'Cabinet Cyclopædia,' p. 201.