508 S. ALEXANDER : which are stages of total individuality, by its want of self- completeness. It is as yet not a totality or a system, and therefore it is in form a mere relation between different bodies or parts of a body (p. 188). Matter as specified in the simplest way is specific gravity : it thereby holds a place and character of its own as compared with the general filling of space by abstract matter (p. 190). But since matter is essentially self-external, this relation or specification appears further as the definite connexion of material parts in a body, or cohesion (pp. 195-205). Such cohesion is of different lands : it may be simple adhesion, i.e., quite indeterminate cohesion, or it may be the coherence (p. 205) of matter with itself, its character of yielding to outward force, while in the very act of yielding it preserves its own mode of composition, as, e.g., brittle glass when struck will break up into pieces, but resists extension ; or thirdly, it may be elasticity, which is cohesion exhibited in motion, the body giving way and yet maintaining itself. This ideality of matter which exists in elasticity is still more visible in sound (p. 205). If cohesion was material space, sound is material time. In sound the indifference or externality of the parts of a body is denied and the body vibrates ; the particles oscillate or momentarily move from their places, but yet they are constrained within the unity of the body and their places restored. " It is the cry of the Ideal under foreign power, but withal its triumph over this power " (p. 209). It is but a step from here to the nature of heat. "It is not only the musician who plays, but the instrument which sounds, that grows hot " (p. 223). Heat is not like sound a mere ideal destruction of cohesion, accompanied by restora- tion of it, but a real destruction ; and the body under heat expands. In sound the external force of the blow is repelled, in heat the body yields and becomes fluid. " This fluidity of body (i.e., its real ideality) is the birthplace of heat, in which sound dies" (p. 224). (3) Hegel's treatment of the idea of animal life is perhaps the most interesting and profitable part of his philosophy of nature, and would well bear a more detailed reproduction than can be given it here. The idea of animal life takes a triple form : it exists first of all as the process in which the organism is self-related, its active unit)' by which it gathers together the many threads of its organs into one. This process Hegel calls the process of fy unit ion (p. 559). This process too is threefold in character, and, as one of the most suggestive results of Hegel's work, deserves a short descrip- tion. It is often recurring in Hegel, and plainly it was to
