this Laws of Affinity. 329 



oxide in the folution, and that of the faline combination 

 brought into action with it, all contribute to the new com- 

 binations which are eftablifhed. 



7. In the chemical action of the metallic folutions, the 

 laws which wc have eftablifhed in that of the other combina- 

 tions might be admitted, if oxidation did not caufe a change 

 in the affinity of the metal, either for the acids or for the 

 other fubftances, and multiply, as it were, in the metals the 

 property of forming combinations; Whence the remits are 

 often fo complicated, that though by accurate obfervation we 

 may develop the facis and the circumftances which deter- 

 mine them, yet they cannot be forefeen by theory, from the 

 mere confideration of the known properties, as may be done 

 with refpe£t to other fubftances, the action of which depends 

 on a fmaller number of conditions. 



8. The date in which oxygen exifts combined in the me- 

 tals, has likewife an influence upon the properties of the me- 

 tallic oxides, and of the precipitates compared with each 

 other. Baycn obferved that feveral mercurial precipitates, 

 as well as the red oxide, detonate ftrongly, though in an 

 unequal manner when cxpofed to heat, after having been 

 mixed with fulphur, and that fome do not poflefs this pro- 

 perty ; but has not given the reaion of the phenomenon and 

 the exceptions. It appears to me indubitable, that this pro- 

 perty of the oxide of mercury, and of the precipitates in which 

 it predominates, is a confequence of the oxygen poflefling 

 more caloric than it preferves in its combination with the 

 fulphur or in the fulphuric acid. The fame thing therefore 

 happens as with the nitrate and oxygenated muriate of pot- 

 afh, except that the effect is lefs confiderable; but in the 

 precipitates of the corrolive mercurial muriate, part only of 

 the mercury can be confidered as not combined with the 

 niuriatic acid, namely, that part which may be reduced into 

 metal by the action of the heat which produces detonation. 

 Such of the precipitates therefore as retain a fufneient quan- 

 tity of the muriatic acid to admit only of a fmall reduction 

 of mercury by the action of heat, cannot produce detonation; 

 and fuch reallv are the precipitates by ammonia, by the car- 

 bonate of ammonia, and by the carbonate of potafh. 



9. The property discovered by Baycn is therefore analo- 

 gous to the fulminating property of the orate and the argen, 

 tate of ammonia; but it is not perceptible in the other me- 

 tallic oxides and precipitates. Hence the oxyjren in the latter 

 muft neceflarily contain a lefs portion of caloric. 



10. The properties which depend upon oxidation vary 

 therefore in each inetal on account of the. proportions of 



oxygen ; 



