42 THE CHEMISTRY OF CREATION. 



bining in the same proportions, do not of 

 necessity generate the same substance. Or- 

 ganic chemistry furnishes numerous instances 

 of this very remarkable fact, in which the 

 greatest diversity of properties is associated with 

 identity of chemical composition."* Thus, 

 while the same substance is always made up of 

 the same elements in the same proportion, the 

 same elements, in the same proportion, do not 

 always form the same substance. This may 

 appear paradoxical, but it is strictly true, 

 although at present we are not quite able to 

 explain or understand the cause. 



2nd. Every chemical body, in uniting with 

 other bodies, does so in a certain definite quan- 

 tity or proportion, or in multiples of that quan- 

 tity, and this is called the "equivalent," or 

 combining proportion of the body. 



For example : When oxygen unites with 

 hydrogen to form water, it does so in this 

 proportion, eight parts oxygen to one hydro- 

 gen. Four parts oxygen would not unite with 

 one of hydrogen, nor any other number but 

 eight, or a multiple of eight, such as sixteen. 

 Again, nitrogen unites with oxygen in the pro- 

 portion of fourteen parts by weight to eight of 

 this gas. Every other element has what is 

 called its combining proportion, or equivalent, 

 * Fownes : Chemistry, p. 174. 



