Itiquir-y into the Lanvs of Affinity,' 101' 



mutual affinity of fome metals which decides their precipitation in the metallic ftate ; fo 

 that this ftate is more or lefs fudden and complete, according to the energy with which: 

 thefe caufes are capable of a£ling *. 



ARTICLE XIV. 



Of the refuhlng Affinity. 



1. I denominate that the refidting affinity, whofe a£lion proceeds from feveral affinities 

 in the fame fubftance : for inftance, the nitric acid is compofed of oxigen and azote ; this 

 acid combines with pot-a(h •, it a£ls upon pot-affi by an affinity which refults from that of 

 the oxigen and that of the azote. The reciprocal mutual adtion of the pot-afli is likewife a 

 force which refults from that exerted by it upon each of the fubftances which compofe the 

 nitric acid. 



2. All bodies exifting upon the earth have an affinity for each other. If we refufe to 

 admit this principle, it muft be allowed, that the number of exceptions can be but very 

 fmall. I may therefore reafon upon this fuppofition, and apply to all fubftances that which 

 obfervation has made known relative to the affinities and their modifications. If this appli- 

 cation be not forced, if it accounts for properties which cannot be diredlly eftablilhed upon 

 experiment, the confiderations which I prefent in this article may throw fome light upon 

 feveral phenomena, which are owing to a chemical a£lion flill undetermined. 



3. I have fuppofed in the definition of refuhlng affinity, that the affinity of a compound 

 fubftance is derived from thofe of the fubftances which compofe it. It is neceflary to exa- 

 mine, what are the circumftances which might modify the elementary affinities, and af- 

 certain the changes which muft have arifen in the affinity refulting from them. 



4. The chemical adtion of fubftances is weakened in proportion to their faturation. 

 (Article II. No. 10.) 



It muft be concluded, therefore, that the refulting affinity muft be a lefs quantity than 

 the elementary affinities when alone : for the latter have experienced a commencement of 

 faturation; but other circumftances may increafe the a£tion of the refulting affinity, or 

 may augment the weaknefs it derives from faturation. 



5. If one of the fubftances that combine, change from a folid to a liquid ftate, it ac- 

 quires the advantages poflefled by folvents; and its affinity, which was difguifed by the 

 folid ftate, becomes adllve, fo that the refulting affinity may, on this account, be much. 

 more confiderable than the elementary affinities appeared to be. 



Thus, when fulphur is diffolved by pot-afti, the fulphuret which proceeds from it exerts 

 a ftrong aftion upon oxigen gas, as foon as it has been rendered liquid by the addition of 

 water, or has attratled fufficient humidity from the air : becaufe it has by that means loft 



* Fabroni has publifhed fome very Inteiefting obfervations on the mutual allien, of rretals. (Journal 

 •It Phyfique, Brumaire, An. 8.) g 



4 . it8-> 



