CATALYSIS. 281 



the power of resolving compounds into new forms, 

 without undergoing any change themselves. Kirchoft' 

 discovered that the presence of an acid, at a certain 

 temperature, converted starch into sugar and gum, no 

 combination with the acid taking place. Thenard found 

 that manganese, platinum, gold, and silver, and, indeed, 

 almost any solid organic body, had the power of decom- 

 posing the binoxide of hydrogen by their presence 

 merely, no action being detected on these bodies. 

 Edmund Davy found that powdered platinum, moistened 

 with alcohol, became red-hot, fired the spirit, and con- 

 verted it into vinegar, without undergoing, itself, any 

 chemical change. Dcebereiner next discovered that 

 spongy platinum fired a current of hydrogen gas 

 directed upon it, which, by combining with the oxygen 

 of the air, formed water. Dulong and Thenard traced 

 the same property, differing only in degree, through 

 iridium, osmium, palladium, gold, silver, and even glass. 

 Further investigation has extended the number of 

 instances ; and it has even been found that a polished 

 plate of platinum has the power of condensing hydrogen 

 and oxygen so forcibly upon its surface, that these gases 

 are drawn into combination and form water, with a 

 development of heat sufficient to ignite the metal. 



This power, whatever it may be, is common in both 

 organic and inorganic nature, and on its important pur- 

 poses Berzelius has the following remarks : 



" This power gives rise to numerous applications in 

 organic nature ; thus, it is only around the eyes of the 

 potato that diastase exists : it is by means of catalytic 

 power that diastase, and that starch, which are insoluble, 

 are converted into sugar and into gum, which, being 

 soluble, form the sap that rises in the germs of the 

 potato. This evident example of the action of catalytic 

 power in an organic secretion, is not, probably, the only 

 one in the animal and vegetable kingdom, and it may 

 hereafter be discovered that it is by an action analogous 



