I. II. III. 



Carbon, . . 73-06 72-85 72-82 



Hydrogen, . . 6-80 6-99 6-89 



Nitrogen, . . 4-53 4-53 4-53 



Oxygen, , . 15-61 15-63 15-76 



100-00 10000 10000 



Results whicli correspond with the formula Cgg Hg^ NOg 

 Mean. Calculation. 



Carbon, . 7291 73-31 Cgg 228 



Hydrogen, . 6-89 6-75 H^^ 21 



Nitrogen, . 4-53 4-50 N 14 



Oxygen, . 1567 15-44 O^ 48 



100-00 100-00 292 



The mean of four closely agreeing analyses of this platinum 



compound gave the following results, which fully confirm this 

 formula : — 



Mean. Calculation. 



100-00 517-2 



From these analyses the author concludes that there can be no 

 doubt that the constitution of bebeerine is represented by the 

 formula Cjg Hgi NOg. 



3. On the Vibrations of Plaue-Polarised Light. By W. J. 

 Macquorn Rankine, Esq. 



If the plane of polarisation is normal to the direction of vibration, 

 according to the conjecture of Fresnel, which .«eems to be supported 

 by the phenomena of reflexion, the velocity of propagation of light 

 in a crystalline medium is a function of the direction of vibration. 



a2 



