T. S. Sunt — Chemical Integration. 117 



hydric gas, without change of volume; the condensation 

 involved in the process of integration being immediately 

 followed by an expansion of similar amount. The law of 

 chemical condensation and chemical expansion being universal, 

 there is theoretically no limit to either of these processes. Such 

 homogeneous expansion or dissociation, it is known, takes place 

 in elemental gaseous species, as when the vapors of sulphur 

 and iodine are exposed to elevated temperatures, as well as in 

 the vapors of compound species like nitric peroxyd, acetic 

 acid and turpentine-oil. 



§ 3. The chemical species, to those agencies which do not 

 effect its disintegration, is a complete entity or integer. This, 

 in the case of homogeneous integration in gases and vapors, is 

 generated by the condensation into a single volume of two or 

 more volumes of a less dense species. The designation of 

 polymers given to such condensed species, implying that they 

 are made up of many parts, carries with it the notion of build- 

 ing by additions, and thus of complexity rather than of integ- 

 rity : it is therefore rejected. 



We assume hydrogen as the type of the normal integer, and 

 the weight of two portions of this element (H 2 = 2"0) being the 

 unit, the weight of a like volume of any other gas or vapor is 

 its equivalent weight; that is to say, the weight of a volume 

 equal to H s . This, in the language of the atomic hypothesis, is 

 its molecular weight; the so called atomic weights being the 

 smallest combining weights of the elemental species, compared 

 with H=l-0. 



§ 4. The normal integers of oxygen, hydrogen and chlorine, 

 and of bromine and iodine vapors, are thus double or dyad 

 integers, while ozone and the vapor of selenium below 800° are 

 triple or triad, and that of sulphur vapor below 550°, is sextuple 

 or hexad ; all of these however at higher temperatures assuming 

 the densities of the normal or dyad integers. The quadruple 

 integers of phosphorus and arsenic vapors, there is reason to 

 believe, undergo a like change ; while the double integer of 

 iodine at about 1500° becomes, as is well known, a single or 

 monad integer, a result which at the highest temperatures of 

 experiment, is already partially attained for bromine and 

 chlorine; the vapors of mercury and cadmium being known to 

 us only in this condition of monad integers. Such a state, from 

 analogy, we may conceive would be attained under favorable 

 conditions of temperature and pressure for the vapors of all 

 known elements, and may, as the writer has elsewhere suggested, 

 actually take place, for many species, in the electric arc; while, 

 as he was the first to point out, in 1867, a still further dissocia- 

 tion, yielding unknown and still more elemental forms, proba- 

 bly appears in solar and nebulous matter. 



