(lOJl Inquiry hiio the Laws 6f jijinity. 



Its force of cohefion, ias if it had been rendered liquid ty the aflion of caloric, and becaufe 

 the pot-afli likewlfc exerts an aftion upon the oxigen, though much weaker than that of 

 the fulphur, fince it cannot alone overcome the elafticity of the gas. The aftion of the 

 fulphur is really diminiflied by the whole of that attraftion which it exerts upon the pbt- 

 afti, and upon the water which ferves as a folvent to the fulphuret; but it gains much 

 more by the liquidity which it acquires, than it lofes by this faturation. Striftly fpeaking, 

 all thofe fubftances of which the folidity is furmounted by a folvent, do a£l by virtue of a 

 rrefulting force or affinity. 



6. Circumftances contrary to the preceding produce an oppofite effeft ; and when fub- 

 iftances by combining, become folid, or more difpofed to cryftaUife, this circumftance is 

 added to the lofs of force, arlfmg from the faturation. 



For example, pot-alh and nitric acid have both the property of diflblving In alcohol, and 

 yet alcohol does not diflblve the nitrate of pot-afli ; that is, the force of cohefion which be- 

 longs to that combination, and which, with water, produces its cryflallifation, has modi- 

 fied the elementary affinities into the refulting affinity. What confirms this explanation is, 

 that falts which are not cryftallifable in water, becaufe they oppofe only a feeble cohefion, 

 have, in general, the property of diflblving in alcohol ; but, in fuch a manner, that they 

 are capable of cryftallifing In that fluid, becaufe the weaker action of the alcohol cannot 

 overcome, except to a certain point, the force of cohefion, of which they are not entirely 

 ^eftitute. The limited folubility of nitrate of pot-afh in water, arifes from the folubility 

 lOf the pot-a(h, as well as of the nitric acid by water being greater than in alcohol. 



7. Bodies a£l in proportion to their quantity, which exifts within the fphere of a6lIon. 

 (Art. IV.) 



Hence we deduce, that an aftlon much ftronger than that of the component parts may 

 ■refult from a combination, when the components, or one of the two, pafs from the elaltic 

 to the liquid ftatc ; for they then carry into the fphere of aftivity a more confiderable quan- 

 tity, the a£lion of which may confiderably exceed the lofs of force that is owing to the 

 faturation. 



Thus pot-afh cannot overcome the refiftance which proceeds from the elafticity of the 

 oxigen gas and the azote gas ; but if thefe two be combined in order to form nitric acid in 

 the liquid ftate, they adt upon the pot-afli ^n a quantity much greater than when they 

 could have applied in the elaftic ftate ; and the refult of their a£Hon, though weakened by 

 a commencement of faturation, Is found to be much more confiderable, than if the azote 

 and oxigen had continued in the elaftic ftate; 



8. The affinity of a fubftance which enters into combination with a compound fubftance, 

 concurs with the elementary affinities of the latter to maintain its compofitlon agalnft the 

 aftlon of foreign fubftances, in proportion to the degree of faturation which It produces. 

 Thus iron eafily carries off oxigen from azote, or rather, it ftiares it, or takes a portion ; 

 but<s foon as the nitric acid is combined with pot-afti, iron can no longer feparate its 



oxigen 



