ELISHA MITCHELL SCIENTIFIC SOCIETY. 81 



M}^ first sug-g^estion is that the wording- of the Nat- 

 ural Ivaw be so changed as to read: " The properties of 

 the elements are dependent upon and determined by the 

 atomic weights. " The somewhat difficult idea of func- 

 tion is simplified and periodicity is subordinated. Then 

 I would substitute the following table for that ordi- 

 narily given. It is not greatly changed, and not much 

 originality is claimed for it, but however slight the 

 changes I would insist upon their value, because they 

 do away w4th the dependence upon periods, and they 

 certainly make the table an easier, more intelligible, 

 and more useful one to the student. There is no forced 

 effort at rounding off any period or group. There is 

 room for additional elements when discovered, but the 

 table is not dependent upon them. 



Ivastly, the inter-relation is more clearly brought 

 out. I do not maintain that this table could ever have 

 been discovered without the idea of periods, though I 

 think it might. The periods still underlie it, but they 

 are out of sight for the present and are not necessary. 

 The table is not dependent upon them. 



There are seven group elements having a mean in- 

 crement of two in their atomic weights. It is by no 

 means essential that there should be just seven of these. 

 At present we do not know more, but I think there is 

 possibly a place for one more having the atomic weight 

 21, differing widely from the others as it occupies a 

 singular position. 



These group elements are also to be called bridge 

 elements as they show marked gradation of properties 

 from one to the other and so serve to bridge over the 

 groups and connect one with the other. Linked to 

 them by an increment of sixteen are seven typical ele- 

 ments. These show the distinctive properties of the 

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