T. S. Hunt — Chemical Integration. 119 



ethers and glycerids, that " these non-gaseous species are gen- 

 erated by the chemical union or identification [integration] of a 

 number of volumes or equivalents of the gaseous species ; which 

 number varies inversely as the density of the species."* From 

 this it follows that all condensation of gases and vapors by cold 

 or pressure, and all fusion, solidification, and vaporization are 

 chemical metamorphoses. The law of volumes, hitherto applied 

 only to gases and vapors, extends to all solid and liquid species, 

 and is a universal law. 



§ 7. The identification of the processes of vaporization and 

 condensation of vapors with chemical change is in accordance 

 with the views enunciated by Henri Sainte-Claire Deville in his 

 researches on dissociation between 1857 and 1865. f These 

 views are well resumed in his final statement, in 1873, — that 

 Isambert in his studies of the compounds of ammonia with 

 chlorids " not only demonstrates the analogy between the 

 phenomena of dissociation and of vaporization, but establishes 

 their complete parallelism." Hence, in the opinion of Deville: 

 "There is, according to these ideas, no essential difference be- 

 tween physical phenomena and chemical phenomena, or rather 

 the passage from the one to the other is continuous."^: It may 

 be said in comment upon this remarkable statement that until 

 the true nature of the processes of volatilization and vaporous 

 condensation had been established those chemical phenomena 

 marked by changes of state had been wrongly regarded as 

 physical (or dynamical) phenomena. By "change of state "are 

 here meant all changes between the conditions of gas, liquid 

 and solid, as also the transformations of these, which are always 

 marked by alterations in density, as well as in other physical 

 characters. Illustrations of these changes are familiar alike in 

 simple and in compound species.§ 



§8. It follows from these considerations that if the law of 

 volumes, recognized bv Gay-Lussac in the changes of gases and 



* American Journal of Science, xliii, 205 ; also the writer's Chemical Geologi- 

 cal Essays, 456, and A Xew Basis for Chemistry, 41, 42. 



f A New Basis for Chemistry, 133- 13 "7. 



% Report by Deville on a memoir by Troost and Hautefeuille, Sur les transfor- 

 mations isomeriques et allotropiques: Comptes Rendus de l'Academie des Sciences, 



(1873) lxxvi. "Isambert non seulement demontre Fanalogie entre les 



phenomenes de dissociation et de vaporization, mais en etablit le parallelisme 

 complet." Tl u'y a aucune difference, d'apres ces ideVs, entre les pheno- 

 menes physiques et les phenomenes chimiques, ou plutot le passage des uns aux 

 autres se fait par, des variations continues." Deville', loco citato. 



§ Of phosphorus, which affords perhaps the most instructive example of these 

 changes, there are known (1) The vaporous species, which according to Victor 

 Meyer gives indication of conversion into a more elemental species at very high 

 temperatures; (2) liquid phosphorus which boils at about 279°, — when it has a 

 density of 1-5285 — and may, under proper condition, be cooled to 20° or even to 

 0°, but below 44° is readily changed, with rise of temperature, into the solid 

 transparent, colorless crystalline species, (3) which is luminous in the air, soluble, 

 poisonous, a non-conductor of electricity, having at 40° a density of T806. This 

 is converted by sun-light, by the action of iodine, by a temperature of 230°, or 



