XIV CONTENTS OF VOL. I. 



parameters — Mille i-'s notation — Topaz — Crystallogi-aphic elements — Variations 

 of form, irregular and regular — Secondary planes — Transitional forms — Analogy 

 with organisms — Law of symmetry — Hemihedrism — Hemimorpliism— Crystals 

 repair injuries — Forms of crystals are modified by the medium they are formed 

 in — Polarisation — Axes of elasticity — Ellipsoid of elasticity — Optic axes — Cubic 

 crystals — Uniaxial crystals— Biaxial crystals — Systems of crystals — Cubic sys- 

 tem — Square prismatic system — Ehombohedral system — Optical properties- 

 Eight prismatic system— Singly oblique system — Doubly oblique system — 

 Anorthic system — Varieties — Boracite — Intermediate forms, showing the true 

 affinities of the rhombohedral system — Afliuities, true and apparent — Herschel- 

 lite — Compoimd crystals: branching, chain-like, double, circular — Snow — 

 Staurolite — Kesemlihince to flowers — Interpenetrating crystals — Tesselated 

 Apophyllite — Analoime— Cleavage Pp. 68 — 83 



CHAPTER VIII. 



THE CHEMISTKY OF LIFE. 



Organisms contrasted with crystals — Accretion and waste — Assimilation — Organic 

 compounds : is the distinction between them and inorganic ones absolute ? — I 

 believe it is — Life works through the chemical forces, as au engineer through a 

 machine — The vital principle defined — Origin of life a question for experiment 

 —Life had its origin in creative jiower — Origin of sj)ecies a distinct question — ■ 

 Organic compounds thenno-positive Pp. 84 — 89 



CHAPTER IX. 



THE DYNAMICS OF LIFE. 



Vegetables form organic compounds, which are oxidised by animals — Their actions 

 are opposite — Animal assimilation — Opposite dynamic functions of animals and 

 vegetables — Animals give out energy — Vegetables take up energy — Dynamic 

 action of vegetables in decomposing carbonic acid — Contrast of vegetables and 

 animals — Vegetable respiration — Organisms transform matter and energy — 

 Relation of vegetables and of animals to energy — Animals produce heat and 

 motion — Motion independent of structure — Animal heat, motion, light, and 

 electricity : their origin is chemical — Does the animal organism store energy ? 

 Illustration from Armstrong's Accumulator — Vital energy — Its nature inex- 

 plicable — Muscular heat in tetanus — Heat produced at death ; and during star- 

 vation — Buoyancy and fatigue — Death from fatigue — Relation of the nervous 

 system to animal heat — Heat of inflamed parts due to nervous action — Insen- 

 tient action — Nervous action always causes transformation of energy, sometimes 

 into motion, sometimes ■into heat — Valentin's experiment — Paralysed limb.s — 

 Eflfect of cutting the spinal cord — Experimental proof that the muscles store 

 energy — Motive powers of vegetables — Vegetables probably store vital energy 



