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VII. Colours in Metal Glasses, in Metallic Films, and in Metallic 



Solutions. //. 



By J. C. MAXWELL GARNETT. 

 Communicated by Professor L ARMOR, Sec.R.S. 



Received May 15, Read June 8, 1905. 

 CONTENTS. 



Pages 



1. Introduction 237-239 



2. Expressions for the optical constants of media containing metal in amorphous or 



granular forms 239-242 



3. Formulae applicable only when the volume proportion of metal is small 242-243- 



4. Calculated numerical value of the optical constants of metal glasses, &c 243-248 



5. Diffusions of gold. The nature and form of the suspended particles 248-255 



6. Diffusions of silver. The nature and form of the suspended particles 255-259 



7. Blue reflection from the stained face of silver glass 259-263 



8. Diffusions of copper. The nature and form of the suspended particles 263-265 



9. Colouring effects of the radiation from radium, cathode rays, c 265-2G7 



10. Numerical values of the optical constants of media containing large volume proportions 



of certain metals 267-276 



11. Colour changes caused by heating metal films 277-282 



12. The exceptional case of beaten metal leaf 282-283 



13. CAREY LEA'S "allotropic" silver 283-285 



14. HERMANN VOGEL'S silver 285-286 



15. Allotropic forms of metal 286-288 



1. Introduction. 



THIS paper is an extension of a previous memoir on the " Colours in Metal Glasses 

 and in Metallic Films "* ; it is concerned with the application of mathematical analysis, 

 akin to that already there developed, to the explanation and coordination of the 

 colours which certain metals are, under a great variety of circumstances, capable of 

 causing. 



* 'Phil. Trans.,' A, 1904, vol. 203, pp. 385-420. 

 VOL. CCV. A 393. 11.10.05 



