On the Electrical Properties of Different Kinds of Glass. 197 

 DIAGRAM VI. Soft iron. 



70 BCf 90 



AmpLitudes. 



O 10 20 SO 



40 



50 



60 C 



the successive operations have had a considerable effect on the 

 behaviour of the wire ; and experiments are being made to elucidate 

 this effect as far as possible. 



Some other points of interest which were observed in these experi- 

 ments are reserved for further investigation in a continuation of the 

 work now in progress. 



" On the Connection between the Electrical Properties and the 

 Chemical Composition of Different Kinds of Glass. Part II." 

 By Professor ANDREW GRAY, LL.D., F.B.S., and Professor 

 JAMES J. DOBBIE, M.A., D.Sc. Eeceived May 25, Head 

 June 21, 1900. 



In a former paper* we described experiments on the electrical 

 qualities of specimens of glass of which the chemical composition was 

 determined by analysis. Results were given for a lead-potash glass 

 made by Messrs. Powell and Sons, of London, a lead-potash glass made 

 by Messrs. Schott and Co., of Jena, a barium glass, and a zinc-soda 

 glass (" Jena glass "), both made by Messrs. Schott and Co. These 



* ' Koy. Soc. Proc.,' No. 390, April 20, 1898. 



