The Principles of Biology I-II. [antikvár]

CHAPTER I. ORGANIC MATTER. § 1. Of the four chief elements which, in various combinations, make up living bodies, three are gaseous. While carbon is known only as a solid, oxygen, hydrogen, and nitrogen are known only in the aeriform state. Under pressures great enough to reduce them almost to the density of liquids these elements have still defied all efforts to liquefy them. There is a certain significance in this. When we remember how those re-distributions of Matter and Motion which constitute Evolution, structural and functional, imply motions in the units that are re-distributed; we shall see a probable meaning in the fact that organic bodies, which exhibit the phenomena of Evolution in so high a degree, are mainly composed of ultimate units having extreme mobility. The properties of substances, though destroyed to sense by combination, are not destroyed in reality : it follows from the persistence of force, that the properties of a compound are resultants of the properties of its components—resultants in which the properties of the components are severally in full action, though greatly obscured by each other. One of the leading properties of each substance is its degree of molecular niobilityj and its degree of molecular mobility more or less sensibly affects the molecular mobilities of the various compounds into which it enters. Hence we may infer some relation between the gaseous form of three out of the four