524 On the Oxidation of Metals in general, 



this led him to believe, supported also by reflections which 

 were the result of many experiments, that probably eveii 

 Jnetals pass from the metallic state to the maximum of oxy- 

 genation bv going throuoh all the intermediate degrees of 

 oxidation in such a manner, that for each metal there is a 

 multitude of different oxides. 



I am well persuaded that the number of metallic oxides is 

 much ffreatcr than most chemists admit, and that they do 

 not pass immediately, as is supposed, at least with respect to 

 some of them, from a weak degree of oxygenation to a very 

 hio^h one ; that between these last there exists one or more 

 intermediate degrees which constitute as many particular 

 oxides : but I confess that I am not yet convinced that there 

 are as many oxides as possible degrees of oxygenation ; and 

 if the theory admits them, experience seems to reject them : 

 in fact, why should not these different oxides combine with 

 acids ? The cause cannot be attributed to any thing else than 

 that metals, at a certain degree of oxidation, have more af- 

 finity for acids than at any other ; but for that very reason 

 it may happen, that, when combined with a given quantity 

 of oxygen, they may form fixed oxides, while with a greater 

 or less quantitv these oxides can only have a momentary 

 existence. The latter would therefore be placed between 

 the former; there would be as many degrees through which 

 the former would be obliged to pass without being able to 

 stop ; and besides, this is exactly what we observe of acids 

 which have the same radical. Will it be said, that between 

 the sulphurous acid and sulphuric acid, between the phos' 

 pkoroxis and phosphoric acids, there are several intermediate 

 acids ? And if these intermediate acids do not exist ; if sul- 

 phur, phosphorus, &c. cannot form any more than two 

 acids, why do metals give birth to such a mu'tiuide of ox- 

 ides ? why should not there be fixed degrees of oxygenation as 

 uell for the one as the other? In short, how couldit happen 

 that hydrogen forms only one oxide, although susceptible of 

 fixing more than five times and a half its weight of oxygen? 

 There are many reasons which incline ns to believe that me- 

 tals are absoluiely like olher combustible bodies ; and al- 

 though it is proved that the latter cannot form, with the ge- 

 neral 



