the Laws of Affinity, I } i 



the force of cohefion is weak, and no combination is made 

 with the phofphorus; hence the effect is but partial, as when 

 iron is ufed. (No. 4.) 



Though the affinity of gold for oxygen is much inferior to 

 that of copper, its precipitation is not fo quickly effected, and 

 a portion is precipitated in the Mate of oxide; probablv bc- 

 caufe it has little difpofition to combine with phoiphorus ; 

 and it is the combination of copper with phoiphorus that 

 determines the precipitation of the latter metal. Some of the 

 obfervations which I have here preferred, require the accu- 

 racy of experiment for their entire explanation: but all ap- 

 pear to me indubitably to prove that it is the force of cohe- 

 lion which tends to recombine the particles of one individual 

 metal, and the mutual affinity of fome metals which decides 

 their precipitation in the metallic ilate ; fo that this ftate is 

 more or lefs fudden and complete, according to the force with 

 which thefe caufes are capable of acting * . 



Xllf. On the refulting Affinity, 



l. The refult of the action of feveral affinities in the fame 

 sfubftance, I denominate the re fulling affinity : for inftance, 

 the nitric acid is com po fed of oxygen and azote; this acid 

 combines with potafh ; it acts upon potafh by an affinity re- 

 fulting from that of the oxygen and of the azote. The re- 

 ciproeal mutual action of the potafh is likewife a force refult- 

 ing from that exerted by it upon each of the fubliances which 

 compofe the nitric acid. 



%. All bodies exiftjng upon the earth have an affinity for 

 each other. If there be exceptions, the number can be but 

 very fmall. I may therefore reafon from this, and apply to 

 all fubftances that which obfervation has made known rela- 

 tive to affinities and their modifications. If this application 

 be not forced, if it accounts for properties which cannot be 

 directly eftablimed upon experiment, the coniiderations which 

 I prefent in this article may throw fome light upon feveral 

 phenomena, which are owing to a chemical action tlill un- 

 determined. 



3. In the definition of refulting affinity , I have fuppofed 

 that the affinity of a compound fubftance is derived from 

 thofe of the fubftances which compofe it. It is neceffarv to 

 examine what circumftances may modify the elementary affi- 

 nities, and to afcertain the changes which muft arife in the 

 affinity refulting from them, 



* Fabrpni has publifhed fome very intercfling obfervations on the rnu- 

 rual a&ion. of metals. {Journal d? PfyfiquCt lkumaire, an. 8 .) 



I £ 4. The 



