CONTENTS OF VOL. I. xiii 



CHAPTER V. 



CHEMICAL ENERGIES. 



Energy giveu out in combination, a constant quantity, and sufficient to decom- 

 pose the compound — Gravitation and affinity — Energy once become actual has 

 been parted with — Misconceptions — Anecdote of an ironmaster — Chemical nota- 

 tion expressive of combinations — Proposed addition to it — Heat-units — Thermal 

 equivalents — Thermo-negative and thermo-positive compounds — Peroxide of 

 liydrogen — Dynamic equivalents of the elements— Red or amorphous phos- 

 phorus. 



Note : — Inaccurate language respecting affinity as a force .... Pp. 47—54 



CHAPTER VI. 



THE MOTIVE POWERS OF THE UNIVERSE. 



Theory of the past and future eternity of the present order of the universe untrue 

 —Reason of this — Definition of motive power — Heat is not always motive 

 power — Illustration from a steam-engine — Transformation of energy of motion 

 into heat, the prevailing tendency — Consequent destruction of motive power — 

 Dissipation of energy — Earth's internal heat is constantly being lost — Geolo- 

 gical consequence — Sun's heat — Meteoric theory — Carrington's observation — 

 Sun hottest at the equator, and why — Motions of the sun's atmosphere — Solar 

 spots — Combustion an insufficient source — Meteoric heat — Infinite supply of 

 meteors possible, but would subvert the equilibrium of the solar system-^Two 

 alternatives : exhaustion of sun's heat, or subversion of equilibrium of the solar 

 system— Is the universe mortal ? — Uncertain — First case— Second case — Third 

 case — Each separate system is mortal — A past eternity impossible — Nebular 

 theory — Transformation of energy in the process of conden.sation — Solar and 

 volcanic heat have the same origm — Potential energy of the original nebula — 

 Rotation of a nebulous mass — Solar radiance the great motive power — The tides 

 — Energy of wind and tide ; their common source Pp. 55 — 67 



CHAPTER VII. 



CRYSTALLIZATION. 



Contrasts and resemblances between crystals and organisms— Species and classes 

 — CrystallLne species defined — Foreign substances modify forms — Forms inter- 

 mediate between species — Analogies with organisms — Dimorphism — Crystals 

 are bounded by plane surfaces : may be described mathematically — Spiral shells 

 — Crystals have a limit of size : are hard : impermeable by water : grow at the 

 surface only: are molecularly immobile — Contrast of organisms — Crystallo- 

 graphic axes— Intercepts— Parameters: their ratios — Ratios of intercepts to 



