well compensated for, if practicability be attained. There is a character about ecclesiastical seals which makes them readily recognisable. Most of them, in accordance with the constitution of Cardinal Otto, have on them the distinctions prescribed by it; and even the private personal seals of ecclesiastics have generally some figure, device, or legend which serves to distinguish them. The seals of the laity are less easily referable to the different classes who used them, since the titles or other designations of the respective individuals less frequently present themselves; beside which, the several classes of the laity were not so clearly defined as those of the clergy, and such lay distinctions as existed in one country, or at one period, would not be found applicable to those of another. However, the seals of sovereigns and of their issue to some extent, and their respective consorts, which can be identified by the legends and heraldry upon them (and such is the case with most of them), might be arranged in classes apart from the rest; and, in like manner, official seals, and the seals of corporations and similar bodies, appearing to be such on the face of them (as nearly all of them do), may form other classes. But the great mass of lay seals would still remain to be disposed of; and they are far too numerous to be comprised under one head. For these, a method of distribution must be devised, irrespective of rank, sex, station, or use; and such as shall be easy of application, and according to distinctions apparent on the seals themselves.
In classification of any kind it is of course of the first importance that the classes should be well defined; but the great difficulty commonly is, to divide the subject in such a way that the several parts of it taken together shall comprise the whole; and so, in like manner, on every sub-division; a difficulty which is greatly increased when the subject can- not be exhausted, but newly discovered genera and species are continually claiming places. For practical purposes, and it is with them only that we are concerned, this object is best effected by always making the last of any number of heads, into which any class is divided, such as will comprise all of that class which are not comprised in the previous heads: so that in every case the last head (whether on the primary division or on any subdivision) will be residuary and miscellaneous.
