32 JOURNAIv OF THE 



ed to them. I have had a student come to me with the 

 confession that he had been able to see nothing- of the at- 

 tractive beauty of the science in his study of it until this 

 system brought law and order into .what had only been 

 confusion to him before. 



The brief time allotted to me gives opportunity only for 

 an earnest plea in behalf of the introduction of the system 

 and does not admit of an extended exposition of the ap- 

 plication. An excellent g-uide alono- this line will be 

 found in the lecture of Lothar Meyer before the German 

 Chemical Society which I have already referred to but 

 let me say that the only truly successful way of teach- 

 ing- this system is for the teacher to make a faithful 

 study of it and its capabilities for himself. It is not the 

 old system of families and it is not to be treated merely 

 as affording- a convenient classification. All that was 

 true in those g-roups it retains but it further develops 

 and in a measure explains them. 



A few of the lines of usefulness of the system may be 

 pointed out. First arbitrary dis.tinctions, such as be- 

 tween metals and non-metals, which have given chemists 

 so much trouble to define and maintain, can be done away 

 with. The Berzelian division into electro-positive, and 

 neg-ative elements is revived and fixed and enables one to 

 account for the g-radations between these elements. 



The s^^stem g-ives a simple, easily remembered and ap- 

 plied arrang-ement of valence in the place of the confu- 

 sion and difficulties of the old methods. 



The full introduction of the periodic system means a 

 consecutive study of the elements as allied bodies. This 

 in a measure resembles the' study of the hydrocarbons in 

 org^anic chemistry. It is very valuable as g-iving- a con- 

 nected view of these bodies. The symmetry of chemistry 

 is better shown and the student feels that he has a grasp 

 of the whole, an intelligent c(n jicl:ciii*cn cf tie pupr- 

 ties chemical behavior and inter-relations of the elements 

 which he can scarcely arrive at by the old way. 



