120 T. S. Hunt — Chemical Integration. 



vapors, is to be extended, as we have maintained, to their con- 

 densation into liquids and solids, so that for these, as for gases, 

 the specific gravity is a function of the equivalent weight, we 

 are forced to the conclusion that the equivalent or integral 

 weights of liquids and solids are much more elevated than has 

 been hitherto supposed. This the writer taught from 1853 up 

 to 1885, although he had not in those years arrived at the 

 simple means of fixing the value of these weights, subsequently 

 set forth in 1886.* 



These elevated equivalent weights furnish illustrations of the 

 great principle of progressive series in chemistry, which, first 

 recognized in 1842, by James Schiel, in the formula of related 

 bodies differing by ??(CH 2 ), and in that form adopted by Charles 

 Gerhardt in 1844, was in 1853 generalized by the present writer, 

 and regarded as a principle of universal application. As then 

 pointed out, progressive series in chemistry may be included 

 under two heads : those in which the first term is the same as 

 the common difference, as seen in polymerization or homogen- 

 eous integration, and those in which it is unlike the common 

 difference. It was at that time asserted that there are progres- 

 sive series, — having homologous relations between their mem- 

 bers — differing* not only by n(CH a ), but by n(OH s ), by w(OM), 

 and by w(SM), as well as by ?i(CM0 3 ). 



The subject was further pursued in a communication to the 

 French Academy of Sciences in 1855, when it was said, "These 

 homologous relations, far from being limited to carbon com- 

 pounds, are but examples of ■ that numeric harmony seen by 

 Laurent, and recognized by Dumas in the equivalents of the 

 elements, which will become for chemistry a principle as wide 

 in its application as those of atomic weights and volumes." Of 

 the writer's studies of the latter, it was further said by him in 

 1855, that they were undertaken "in the hope of giving to 

 mineral chemistry something of that exactitude which organic 

 chemistry already possesses. "f 



more rapidly, with evolution of heat from the condensation, when exposed to the 

 temperature of boiling- sulphur [450°] into (4) the amorphous red species, insolu- 

 ble, non-luminous, and non-poisonous, with a density of about 2-]0. This species 

 volatilizes in vacuo, without fusion, at 550° and is re-deposited in red crystals, 

 which are perhaps identical with the red crystallized metalloidal species (5) got 

 by melting lead with phosphorus under pressure, which has a density of 2 - 34 at 

 15°, and is a conductor of electricity. The forms of red phosphorus with inter- 

 mediate densities are possibly mixtures of the last two species. 



* See A New Basis for Chemistry, 100, 111. 



f Comptes Rendus de l'Acad. des Sciences, xli. 77-81 ; sur les volumes atom- 

 iques. "Ces rapports d'homologie, loin d'etre limites aux composes de carbone, ne 

 sont que des examples de cette harmonie numeriqne que voyait deja Laurent, que 

 Dumas a reconnue dans les equivalents des elements, et qui d'eviendrait pour la 

 chimie un principe d'une application aussi large que ceux des poids et des 

 volumes atomiques." "Dans 1'espoir de donnera la chimie minerale quelque chose 

 de cette exactitude que possede deja la chimie organique." Loco citato. 



