TABLE OF CONTENTS. XXI 



XVI. 



THEORY OF CHEMICAL CHANGES AND EQUIVALENT VOLUMES 



(1853). 



The physical and chemical history of matter 426 



Generation of chemical species considered 427 



Theory of double decomposition 428 



On the relations of lower to higher species 428 



The significance of combination by volumes 429 



The nature of chemical union and of solution 429 



Relations of chlorine to hydrogen and hydrocarbons .... 430 



Laurent's law of divisibility in formulas 431 



Reasons for doubling the equivalents of oxygen and carbon . . . 431 



Extension of the principle of progressive series 432 



Relations between density and equivalent weight in gases . . . 432 



Relations between density and equivalent weight in solids . . . 433 



High equivalent weights of solid species ...... 434 



Playfuir and Joule on equivalent volumes . x 434 



Equivalent volumes of crystalline solids 435 



Equivalent volumes of liquid species 436 



XVII. 



THE CONSTITUTION AND EQUIVALENT VOLUME OF MINERAL 

 SPECIES (1853-1863). 



Progressive or homologous series in chemistry ..... 439 



General formula for silica and other oxides 440 



Equivalent volume of certain salts 440 



Probable constitution of the carbon-spars 441 



Illustrations of isomorphism and /rf homology ..... 442 



Relations between the various triclinic feldspars 443 



A similar view subsequently adopted by Tschermak .... 444 



The feldspathides ; scapolites, beryl, and iolite 445 



The grenatides; zoisite or saussurite ....... 446 



Polymerism in mineral species illustrated 446 



Relations between the jades and the scapolites 447 



The allomerism of Professor Cooke 447 



XVIII. 



THOUGHTS ON SOLUTION AND THE CHEMICAL PROCESS (1854). 



Views of various chemists as to the nature of solution . ... 448 



Solution maintained to be chemical union 449 



Chemical union is identification 450 



Chemical decomposition or differentiation 451 



Nature of double decomposition ........ 451 



Action by pressure or catalysis 452 



