AND ITS SELF-CONSEKVATIOJtf. 95 



compounds. Thus, the several oxides of nitrogen already 

 referred to present each its own group of distinguishing 

 qualitative characteristics. 



The whole of chemistry is, indeed, but an extended illus- 

 tration of this, so that we need here do no more than call 

 special attention to the immense number of exceedingly 

 complex compounds which carbon forms with one or more 

 of the three other elements, oxygen, hydrogen and nitro- 

 gen the great number of the compounds being rendered 

 possible, as the chemists assure us, by a "fundamental 

 and distinctive property of carbon itself." That property 

 is the power, possessed by no other element in so high a 

 degree, of combining with itself, and forming a variable 

 basis for multitudes of complicated compounds involving 

 one or more of the other elements just named. 



The point we have here specially to emphasize is, that 

 the mere variation of the quantitative relations in the 

 combinations of these four elements gives rise to the entire 

 series of qualitative differences which lend such immense 

 variety to the products, both of the vegetal and of the 

 animal world. 



To what has been said respecting the relation between 

 extensive and intensive quantity as illustrated in chem- 

 istry, there may be added the following, from what is 

 known of electricity. Statical electricity is said to be 

 characterized by intensity, while dynamical electricity is 

 distinguished by its quantity. And yet these two modes 

 of electricity do not differ in kind, but rather in the 

 mode of their development, which fact becomes explicit 

 in the alternative names: frictional and chemical 

 electricity. Not only so, but a Leyden jar may as well 



