I36 Refcarches rtfpeStlng. 



one is added that tends to form a combination into which 

 one of the conftituent parts muft enter. For example, when 

 fulphuric acid is added to a mixture of water and iron, this 

 acid favours the decompofition of the water, becaufe it tends 

 to combine with the metal, and with a portion of oxygen ; a 

 tendency concurring, with that of the metal, againft the affi- 

 nity which forms the combination of oxygen with hydrogen. 

 10. From the preceding remarks we conclude, that the 

 properties of the refill ting affinity of compound fubftances 

 may be reduced, 1. To the advantages of liquidity, and under 

 this point of view it is neceftary to apply to it the theory of 

 folvenis (Art. IX.): 2 To the difpofition to folidity, which 

 produces contrary effects, which muft be explained by the 

 force of cohefion (Art. V.): 3. Laftlv, to the concentration 

 of elaftic fubftances. The observations prefented in No. 7. 

 and 8. prove that, in thofe compounds in which elaftic fub- 

 ftances are concentrated, there are eftablifhed, by a change 

 of conftitution, affinities which maybe considered as new ; 

 an additional force has accrued, to which we may apply the 

 jnverfc of what has been Rated relative to the effects of ela- 

 sticity (Art. VI.) The diftin&ive character of the complex 

 affinities treated of, (Art. XII.) compared with thofe which 

 refult from the compaction of the fubftances of which I now 

 fpeak, is, that in the firft: but very little change obtains in 

 the conftitution of the component parts; fo that, when the 

 force of cohefion or of elaftieity does not intervene, we may 

 confider them in the fame manner as they have been eortfi- 

 dered in Art. XII. No. 1., whereas anew force is eftablifhed 

 in compounds in which elaftic fubftances are condenfed ; a 

 power which may be conftdered as analogous to that of the 

 cohefion which obtains on the mixture of different fubftances 

 that determine the combinations that are formed, or which 

 require to be overcome by the forces oppofed to it, 



11. Caloric, by augmenting elaftieity, deftroys the affinity 

 of fubftances, of which the conftituent parts have an un- 

 equal dilatation, conformably to what has been ftated in/ 

 Art. VII. 



12. Obfervation further (hows us, that when the refulting 

 affinity is not fuffieient to prevent the decompofition, it fome- 

 times renders it very flow and tedious To this flownels of 

 action, to thefe progreflive changes of conftitution, to the 

 different degrees of fa tu rati on which take place, muft be 

 alcribed moft of the phenomena obfervable in vegeta- 

 tion, fermentation, the animal ceconomy, and, in gene- 

 ral, among all bodies which contain condenfed elaftic 



fubftances. 



