essays can be judged by all who are capable of thinking. The feature that strikes us most in reperusing these volumes, and to which we have before called attention as a characteristic of his writings, is the mastery they display of the art of luminous exposition in dealing with obscure and abstruse subjects. Here Clifford is quite incomparable, and there are parts of these volumes which will long survive as models of popular statement, delightful to the reader from their vividness and marvelous lucidity. Clifford is at his best in disentangling and laying out to view subjects which baffle ordinary grasp and penetration. He may be said to make perfectly clear things which ordinary people complain that they can only partially and imperfectly understand. To take a random example, we open volume one, and happen to strike, in the middle of it, a discourse upon atoms. This might be at once taken as a crucial test of Clifford's power of picturing by language. Everybody knows something about atoms, and everybody is bewildered in the attempt to form such a conception of them as will explain the mutual influences and interactions of the material bodies which are composed of atoms. Turning to the beginning of this lecture, which was a popular effort in a Sunday course, we find him thus opening his subject
I want you to remember that fact, because it is of capital importance for the arguments we shall have to consider to-night. The very same note which I can get the tumbler to give out by agitating it, by rubbing the edge, that same note I can also get the tumbler to answer back to me when I sing to it. Now, remembering that, please to conceive a rather complicated thing that I am now going to describe to you. The same property that belongs to the glass belongs also to a bell which is made out of metal. If that bell is agitated by being struck, or in any other way, it will give out the same sound that it will answer back, if you sing that sound to it; but if yon sing a different sound to it then it will not answer.
Now, suppose that I have several of these metal bells which answer to quite different notes, and that they are all fastened to a set of elastic stalks which spring out of a certain center to which they are fastened. All these bells, then, are not only fastened to these stalks, but they are held there in such a way that they can spin round upon the points to which they are fastened.And then the center to which these elastic stalks are fastened or suspended you may imagine as able to move in all manners of directions, and that the whole structure made up of these bells and stalks and center is able to spin round any axis whatever. We must also suppose that there is surrounding this structure a certain framework. We will suppose the framework to be made of some elastic material, so that it is able to be pressed in to a certain extent. Suppose that. framework is made of whalebone, if yon like. This structure I am going for the present to call an "atom." I do not mean to say that atoms are made of a structure like that. I do not mean to say that there is anything in an atom which is in the shape of a bell: and I do not mean to say that there is anything analogous to an elastic stalk in it. But what I mean is this — that an atom is something that is capable of vibrating at certain definite rates; also that it is capable of other motions of its parts besides those vibrations at certain definite rates; and also that it is capable of spinning round about any axis. Now, by the framework which I suppose to be put round that structure, made out of bells and elastic stalks, I mean this — that supposing you bad two such structures, then you can not put them closer together than a certain distance, but they will begin to resist being put close together, after yon have put them as near as that, and they will push each other away if you attempt to put them closer. That is all I mean, then. Yon must only suppose that that structure is described, and that set of ideas is put together just for the sake of giving us some definite notion of a thing which has similar properties to that structure. But you must not suppose that there is any special part of an atom which has got a bell-like form, or any part like an elastic stalk made out of whalebone.
A large part of these essays is devoted to the discussion of the moral and religious problems which so prominently occupy the speculative attention of the age-. These subjects are all handled with the author's customary originality and felicity; but it is impossible here to give any account of them. He attempted no system, and his work must be looked upon as consisting of elaborate fragments, valuable for what they are separately worth. We quote a portion of the criticism passed upon him by the London "Spectator":