CATALYSIS, OR ACTION OF PRESENCE. 91 



These hasten decay ; and next in power to lime, in 

 this singular process, is alumina, then oxide of iron, 

 in passing from a lower to a higher state of oxida- 

 tion. 



137. This remarkable process, this power, energy, 

 function, influence, property, called by whatsoever 

 name it may be, which is thus exerted, by the ele- 

 ments of silicates upon vegetable fibre, and insolu- 

 ble geine ; and the power of developing acid proper- 

 ties in that principle, is intimately connected, with 

 the action of growing plants upon soil. The joint 

 effect of organic and inorganic elements of soil and 

 plants, may be better understood by adverting to the 

 probable cause of this property of earths, alkalies 

 and oxides ; though in the present state of science 

 this cause may be apprehended only by giving it a 

 name, which, while it arranges many facts under 

 one view only, hides as deep, the source of this clas- 

 sification. The cause of this effect, of alkalies, upon 

 geine, is to be sought in that power, which has been 

 denominated catalysis, and which the French desig- 

 nate as the action of presence. That is, the mere 

 presence of a body, influences the nature of a sec- 

 ond body, so as wholly to change its properties. It 

 causes the elements of organic compounds to enter 

 into new arrangements, by which they produce a to- 



