First, there is Protoplasm--the "Physical Basis of Life," or Living Matter, being that form of matter by which life is always accompanied. In this no chemical element unknown elsewhere, is to be found; the cells of which it consists are compounded of Oxygen, Hydrogen, Nitrogen, and Carbon; and it has been argued, especially by Huxley, that it is therefore not different in kind from other compounds; that as Oxygen and Hydrogen form water, Oxygen and Carbon, Carbonic Acid, Hydrogen and Nitrogen, Ammonia,--so the four combined, in proper circumstances and proportions, make Living Matter, without the aid of any vital force or principle. And Haeckel with his habitual audacity foretells the artificial production of Protoplasm for purposes of commerce. But, as Mr. Stirling observes,[95] man has always known that he is made of dust, and that the only part of him perceptible to sense is substantially the same as the earth beneath his feet. All that he now learns in addition is that when such matter is wedded to life it undergoes marvellous transformations which in part at least we are able to recognize, but are wholly unable to comprehend. This Professor Huxley himself admits: The properties of living matter [he writes][96] distinguish it absolutely from all other kinds of things, and the present state of knowledge furnishes us with no link between the living and the not-living. Not only that: the subject is full of complexities of which Professor Huxley gives no hint, and which it would even seem he did not himself perceive. In his celebrated lecture on the Physical Basis of Life[97] he gives his hearers to understand that all Protoplasm is the same, that its particles are as the bricks with which any sort of edifice may be constructed, a cathedral or a gin-shop, a palace or a hovel. The protoplasm of a mushroom, for instance, he declares to be essentially identical with that of him who eats it, into which it is most readily convertible. He also speaks of the effect of eating mutton being to "transubstantiate sheep into man." But, positive as are these statements, they are far from representing scientific truths, and we are told by Sir William Thiselton-Dyer that he himself would not know what to do with a candidate who should advance such views in an examination.[98] As to the mushroom and the mutton, Sir William adds, that except the definition of a crab, as a red fish that runs backwards, attributed to the French Academy, he can call to mind no statement "so compact of error."