Angular Measurement of Optic Axial Emergences. 7 



June 18, 1896 continued. 



VI. " Experimental Proof of van't Hoff's Constant, Dalton's Law. 

 &c., in very dilute Solutions." By Dr. MEYER WILDERMAXN, 

 Communicated by Professor FITZGERALD, F.R.S. 



VII. " On the Determination of the Wave-length of Electric Radia- 

 tion by Diffraction Gratings." By J. C. BOSE. Communicated 

 by LORD RATLEIGH, Sec. R.S. 



VIII. " The Effects of a strong Magnetic Field upon Electric Dis- 

 charges in Vacuo." By A. A. C. SWINTON. Communicated by 

 LORD KELVIN, F.R.S. 



IX. " On the Structure of Metals, its Origin and Changes." By 

 M. F. OSMOND and Professor ROBERTS- AUSTEN, C.B., F.R.S. 



X. "Magnetisation of Liquids." By JOHN S. TOWNSEND. Com- 

 municated by Professor J. J. THOMSON, F.R.S. 



XI. " Selective Absorption of Rontgen Rays." By J. A. 

 MCCLELLAND. Communicated by Professor J. J. THOMSON 

 F.R.S. 



XII. "On the Determination of Freezing Points." By J. A. 

 BARKER, D.Sc. Communicated by Professor SCHUSTER, F.R.S. 



XIII. " The Menstruation and Ovulation of Macacus rhesus ; with 

 Observations on the Changes undergone by the discharged 

 Follicle. Part II." By WALTER HEAPE. Communicated by 

 Dr. M. FOSTER, Sec. R.S. 



XIV. " Phenomena resulting from Interruption of Afferent and 

 Efferent Tracts of the Cerebellum." By Dr. J. S. RISIEN 

 RUSSELL. Communicated by Professor V. HORSLEY, F.R.S. 



The Society adjourned over the Long Vacation to Thursday, 

 November 19. 



"Angular Measurement of Optic Axial Emergences." By 

 WILLIAM JACKSON POPE. Communicated by Professor 

 ARMSTRONG, F.R.S. Received February 7, Read March 

 19, 1896. 



Crystals belonging to the monoclinic or anorthic systems are rarely 

 obtained in which the optical orientation is such that a large 

 crystal face is so nearly perpendicular to a bisectrix that the 

 apparent optic axial angle as observed in air can be directly measured 

 by means of the ordinary Fuess apparatus. It thus becomes 



