344 ORGANIC CHEMISTY. 



them have basic properties. Many of them are strikingly 

 similar to ammonia in odor and other properties. These 

 substitution compounds afford still further evidence of 

 the influence of arrangement of atoms and molecules 

 in determining the character of chemical compounds. 

 Many of these bodies differ very widely in their com- 

 position, and are yet closely allied in their properties. 

 The methods of producing the substitutions above 

 mentioned, are not of interest to the general student. 

 A general notion of substitutions may be obtained from 

 the double decompositions with which the student is 

 already familiar. 



