74 
Mr. kirwan’s Experiments and Objervations on 
Divellent. 
Vitriolic acid to calx of iron 
Copper to its phlogiflon 
270 Vitriolic acid to copper 
360 Calx of iron to phlogiflon 
260 
250 
Sum 
630 
Sum 
510 
Hence, In this cafe, no decompofition can happen ; but in 
the fecond cafe, much of the phlogiflon of the folution of 
iron having efcaped, the affinity of the calx of iron to acid is 
diminifhed, and that to phlogiflon is increafed, and therefore 
the quiefcent affinities may be fuppofed, 
Vitriolic acid to the calx of iron 240 
Copper to its phlogiflon - 360 
600 
and the divellent. 
Vitriolic acid to copper - 260 
Calx of iron to phlogiflon 370 
630 
But from the increafed affinity of the calx of iron to phlo- 
gillon it might be inferred, that as the iron recovers its phlo- 
giflon, the acid fhould re-aCt upon it and quit the copper ; and 
this would certainly happen, if it recovered its phlogiflon in 
fufficient quantity, but the accefs of air and heat prevents its 
retaining it, at leafl in fufficient quantity. 
This increafed affinity of th£ calx of iron to phlogiflon is not 
a mere fuppofition ; for, if into a folution of iron, fo far de- 
phlogiflicated as to refufe to cryflallize, fome frefh iron be put, 
the impoverifhed calx will re-attra& fo much of the phlogiflon 
given out during the folution of the frefh iron, that it will 
now afford cryflals, as Mr. monnet has obferved in his excel- 
lent Treatife on Vitriolization. The diminifhed attraction of 
the calx of iron to acids is alfo evident from this experiment, 
4 and 
