vi Contents. 



February 7, 1881. PAGB 



Determination of the greatest height consistent with stability that a 

 vertical pole or mast can be made, and of the greatest height to 

 which a tree of given proportions can grow. By A. G. Greenhill . 65 



February 21, 1881. 

 On the estimation of ferment in gland-cells by means of osmic acid. By 



J. N. Langley 74 



March 7, 1881. 

 On the action of the vagus nerve upon the frog's heart. By W. H. 



GaskeU 7.". 



*On the ancestral form of the chordata. By F. M. Balfour . . . 7(i 



March 21, 1881. 

 On conjugate functions of Cartesians and other quartics. By A. G. 



Greenhill ' ' 



*On a mathematical law of interest in political economy. By Akin- 



Karoly . % 92 



May 9, 1881. 

 On the probable secular change in the position and aspect of the con- 

 stellation Ursa Major. By J. B. Pearson 93 



On sympathetic needles. By J. B. Pearson 96 . 



May 23, 1881. 

 On the elliptic-function solution of the ecpiation ^ 3 +y 3 -l = 0. By 



Professor Cayley 106 



Continued observations on the state of an eye affected with a peculiar 



malformation. By Sir G. B. Airy 109 



On the mechanism of the renal secretion. By C. S. Roy . . .110 



October 31, 1881. 



Remarks by the President 118 



Note on Abel's theorem. By Professor Cayley 119 



November 14, 1881. 

 On the rocks of the Channel Islands. No. II. By Professor Liveing . 122 



November 28, 1881. 

 Celestial chemistry from the time of Newton. By T. Sterry-Hunt . 129 

 On the upper Bagshot Sands of Hordwell Cliffs, Hampshire. By E. B. 



Tawney 140 



On some equations connected with the electro-magnetic theory of light. 



By R. T. Glazebrook 155 



On a method of deriving formulae in elliptic functions. By J. W. L. 



Glaisher 186 



