Catalytic Phanomena with Allolropy. 449 



Now if the spontaneous act of decomposition of the peroxide of 

 hydrogen were, as such, the immediate cause of the decomposition 

 of the oxide of gold, we should expect that the action would not 

 be greater than the cause ; that is to say, that the decomposition 

 of the more permanent oxide of gold, or of the peroxide of hy- 

 drogen itself, would not be more active than the original spon- 

 taneous decomposition of the latter compound. 



But since, as experiment shows, the noble metals effect the 

 decomposition of peroxide of hydrogen with just as much activity 

 as their oxides, it must be assumed that in these cases the cause 

 of decomposition lies in the metals themselves. From their ele- 

 mentary nature, however, these bodies cannot be in a state of 

 decomposition, and they cannot therefore transfer such a state 

 of decomposition to the peroxide of hydrogen ; and hence the 

 immediate cause of the more rapid decomposition of these bodies 

 effected by metalhc gold, &c., must be sought for in something 

 else than in the transference of the chemical activity of one sub- 

 stance to another. However this may be, it appears possible 

 that the action exerted by gold and by its oxide upon peroxide 

 of hydrogen arises from one and the same cause, and that HO^ 

 is directly decomposed by oxide of gold. 



I have previously shown, and have here more fully mentioned 

 the fact, that a great number of substances which decompose 

 peroxide of hydrogen into water and possess also the property 

 of converting free O into ; and the oxides of the noble metals, 

 and the metallic peroxides, belong more especially to this cate- 

 goiy. For this reason I am of opinion that the immediate cause 

 of the decomposition of the HO^ effected by these substances^lies 

 in the allotropic modification which they produce in the of 

 this compound. ^ 



But since not only HO + loses the half of its oxygen, but the 

 oxide of gold, the oxygen of which is^O, is reduced also, I must 

 assume that the transformation of the O of HO + O into causes 

 also the same change of the of AuO^ ; that is, that both com- 

 pounds containing O mutually decompose each other, without 

 being able to adduce any reason for it. 



Mitscherlich, if I mistake not, has succeeded, by observing 

 certain precautions, in decomposing 300 parts of sugar into 

 alcohol and carbonic acid by means of 1 part of yeast. And 

 this distinguished chemist has drawn from thence the conclusion, 

 that the fermentation of sugar has no necessary connexion with 

 the destruction of the yeast. He therefore thinks that if we 

 could remove the causes which produce the destruction of the 

 yeast, which are independent of the saccharine fermentation as 

 such, we might by a given quantity of yeast effect the change of 

 any quantity of sugar into alcohol and carbonic acid, just as we 



