THE TABLE OF THE LAW. 27 



the same column with beryllium, aluminum with boron, 

 silicon with carbon, phosphorus with nitrogen, sulphur 

 with oxygen, and chlorine with fluorine, all of them 

 very much alike in their properties, in pairs. This is, of 

 course, sufficiently remarkable, but let us begin the third 

 line with the next element potassium (K). It falls 

 straight into place in the same column with sodium and 

 lithium, which it greatly resembles ; calcium with beryllium 

 and magnesium, titanium with carbon and silicon, vanadium 

 with nitrogen and phosphorus, chromium with oxygen and 

 sulphur, and manganese with chlorine and fluorine. Strik- 

 ing analogies again appear between the three members of 

 each group. The members of each group have remarkably 

 similar properties. We now see in this scheme, so far, a 

 verification of the Triads of Dobereiner, for the three ele- 

 ments in each group constitute a triad of the kind discov- 

 ered by him. We see, also, that it is a verification of the 

 Octaves of Newlands. But Newlands, as we shall see, had 

 but a faintest glimpse of the sweep of this bold general- 

 ization, which laid stress not only on the fact that every 

 eighth element resembled the first, but also on the periodicity 

 of the phenomenon. In order to grasp the meaning of this, 

 let us notice that to make this arrangement true and valid, 

 he found it necessary to leave a blank space in Group 3, 

 Series 4, for some element hitherto undiscovered, and not 

 content with this, he proceeded to predict the properties 

 it should possess when discovered! 



Here is the full Periodic System of the elements as it 

 exists to-day: 



