of wood as we may wish, and divide it into two equal parts, these (unlike the piece of chalk or iron) will not be the same; the graining will show a difference to the naked eye. The microscope will show that the wood is not uniform in its smallest parts; it is what we may term “organised,” the structure being different as we shift the eye along the smallest distance of the thinnest section. The same applies to bone and muscle; in fact, to all parts of the bodies of all animals and plants. The idea, then, of molecule is a conception of an ultimate bit of a substance towards which our experimental breaking has in actual experience partially reduced it, and would never have occurred to the ancients had the commonest objects of nature been, like variegated marble or granite, of obvious heterogeneous structure. When, therefore, we translate this idea to the realm of biology, where bodies are not made up of similar parts, it is obvious that we do this without warrant, in face of our biological experience, and that we are thoughtlessly accepting a physical theory of gases and incandescent solids without appreciating the foundation upon which this theory rests. The fact of the matter is, we are in utter ignorance as to the ultimate constitution of any living matter; but so far as microscopic investigation goes, we learn that it has unlike--not like--parts. Our experience, therefore, rather contradicts the belief that it will be found to consist of ultimate parts, each part having the function of living protoplasm, biophores, or whatever name may be attached to them; and we recall Clifford’s rule that we may believe what goes beyond our experience only when it is inferred from that experience by the assumption that what we do not know is like what we know.[37] THE END. FOOTNOTES [33] “Life and Letters,” first edition, vol. iii., p. 44. [34] “Life and Letters,” vol. ii., p. 14. [35] Essay to be found in vol. i.; English translation, 1889. [36] Lecture on Heredity, _op. cit._, p. 77. [37] “Lectures and Essays,” vol. ii., p. 210. _Printed by Cowan & Co., Limited, Perth._ SOCIAL SCIENCE SERIES. _SCARLET CLOTH, EACH 2s. 6d._ 1. =Work and Wages.= Prof. J. E. THOROLD ROGERS. “Nothing that Professor Rogers writes can fail to be of interest to thoughtful people.”--_Athenæum_. 2. =Civilisation: its Cause and Cure.= EDWARD CARPENTER. “No passing piece of polemics, but a permanent possession.”-- _Scottish Review_. 3. =Quintessence of Socialism.= Dr. SCHÄFFLE. “Precisely the manual needed. Brief, lucid, fair and wise.”-- _British Weekly_. 4. =Darwinism and Politics.= D. G. RITCHIE, M.A. (Oxon.). New Edition, with two additional Essays on HUMAN EVOLUTION. “One of the most suggestive books we have met with.”--_Literary World_. 5. =Religion of Socialism.= E. BELFORT BAX.