76 JOURNAL OF THE 



step nearer to it in the recog'nition of the fact that the 

 properties of the elements are dependent upon and de- 

 termined by the atomic weig'hts. 



THE PERIODIC LAW. 



A quarter of a centur}^ has passed since the first 

 announcement of the Natural Law and the publication 

 of MendelejefiF's table. The truth of the law in a g'en- 

 eral way seemed to be accepted very readily by chem- 

 ists. It was incorporated in text-books and there ex- 

 plained, but comparatively little use has been made of 

 it in teaching" the science. Even MendelejefT himself, 

 in his Principles of Chemistry, has not made the full- 

 est use of it. Victor Meyer, in his lecture before the 

 German Chemical Society more than a year ago, 

 showed how it might be used and how he used it him- 

 self, and probably, this will do much toward popular- 

 izing its use. 



There must be some reason why so great a help to 

 scientific study is not made more use of. Does it lie in 

 a lingering distrust of the law itself or failure to accept 

 it or is it because of the imperfections in the arrange- 

 ments of the elements oflFered by Mendelejeff and 

 others? It is most probably due to the latter and this 

 paper is presented with the hope of clearing up some 

 of these difficulties. 



The modern chemical world has recognized in the dis- 

 covery of Mendelejeff the greatest step forward since 

 the announcement of the atomic theor3\ It is too much to 

 expect that so great a discovery should spring full-pano- 

 plied from the head of its author. It has been accepted 

 by chemists in all lands and is the basis of present chem- 

 ical thought. Doubtless many have observed the im- 



