PROCEEDINGS OF SECTION J. 



727 



chloride with manganese dioxide and sulphuric acid. The net result 

 is regarded as the combined effect of at least three components — 



Manganese dioxide -^ [Manganous oxide] -\- [Oxjgen] 



Manganous V/ oxide 



Hydrogen 



Sodium 

 Hvdrogen 



sulphate 



\ / chloride 

 /\ sulphate 



Manganous sulphate 

 Hydrogen oxide 



Sodium sulphate 

 [Hydrogen chloride] 



[Hydrogen chloride] 

 [Oxygen] 



Hydrogen oxide 



Chlorine 



The arrow replaces the sign of equality to represent the dynamical 

 character of chemical reaction. The principle of mass action is always 

 kept prominent. 



No charts are used for qualitative analysis. After going through 

 the above course the student is capable of performing ordinary quali- 

 tative analysis by the aid of his own notes, and of doing it in a rational 

 way. A student who was capable of dealing with this work when 

 taking it up would, at the end of the year, have a clear conception of 

 the elementary principles of chemistry. In the next year he should 

 perform quantitative analysis, estimating the metallic and acid radicals 

 in pure salts, obtaining at the same time some knowledge of the purifica- 

 tion of salts. He would become familiar with the quantitative aspect 

 of the chemical theory of quantivalence. He would at this stage have 

 a solid foundation on which a sound superstructure could be erected 

 if necessary. Such a foundation should, I think, be laid before dealing 

 with any broad generalisations involving the ultimate constitution of 

 matter. It is not necessary up to this stage to have the orthodox 

 knowledge of the nature of atoms and molecules. 



In conclusion, I think that this association might with advantage 

 identify itself closely, as the mother association does, with the work of 

 maintaining the best methods in the teaching of science. 



4.— NEUEITIS, NEUEASTH^NIA, AND MENTAL DISEASES. 

 By A. D. LEITH NAPIER, 21. D., F.B.S. (Ed.) 



