CLASSIFICATION. 419 



appears are more numerous than all the other compounds 

 known to chemists. Almost the whole of the substances 

 which have been called organic contain carbon, and are 

 probably held together by the carbon atoms, so that many 

 chemists are now inclined to abandon the name Organic 

 Chemistry, and substitute the name Chemistry of the 

 Carbon Compounds. It used to be believed that the 

 production of the so-called organic compounds was due 

 solely to the action of a vital force, or some inexplicable 

 cause involved in the phenomena of life, but it is now 

 found that chemists are able to commence with the 

 elementary materials, pure carbon, hydrogen, and oxygen, 

 and by strictly chemical operations, combine these together 

 so as to form complicated organic compounds. So many 

 compounds have already been thus formed that the proba- 

 bility is very great that many others will be so formed in 

 the course of time, and we might be inclined to generalize, 

 and infer that all so-called organic compounds might ulti- 

 mately be produced without the agency of living beings. 

 Thus the distinction between the organic and the inorganic 

 kingdoms seems to be breaking down, but our wonder at 

 the peculiar powers of carbon must increase at the same 

 time. 



In considering generalization, the law of continuity was 

 applied chiefly to physical properties capable of mathe- 

 matical treatment. But in the classificatory sciences, also, 

 the same important principle is often beautifully ex- 

 emplified. Many objects or events seem to be entirely 

 exceptional and abnormal, and in regard to degree or 

 magnitude they may be so termed. We might adduce 

 examples on the one hand of such extreme cases, but it 

 is often easy to show, on the other hand, that they are 

 connected by intermediate links with other apparently 

 different cases. 



In the organic kingdoms of nature there is a common 



E e 2 



