VI CONTENTS. 



ARTICLE PAGE 



IX. — On the Motion of Developable Cylinders. By James Bot- 



tomley, B.A., D.Sc, F.O.S 82 



X. — On the Development of the Common Frog. By Thomas 



Alcock, M.D 89 



XI. — On the Levenshulme Limestone : a Section from Slade Lane 



eastwards. By Wji. Brockbank, F.G.S 125 



XII. — On the Transformations of a Logical Proposition contain- 

 ing a single Relative Term. By Joseph John Murphy. 

 Communicated by the Rev. Robert Harley, F.R.S 132 



XIII. — List of the Phanerogams of Key West, South Florida, 

 mostly observed there in March, 1872. By J. Cosmo 

 Melvill, M.A., F.L.S 138 



XIV. — On the Occurrence of Caffeine in the Leaves of Tea and 

 Coffee grown at Kew Gardens. By C. Schorlemmer, 

 F.R.S 155 



XV. — On the Change produced in the Motion of an Oscillating 

 Bod by a Heavy Ring surrounding it and attached to 

 it by Elastic Cords. By James Bottomley, B.A., D.Sc, 

 F.C.S 158 



XVI.— On the Leaves of Catha edulis. By C. Schorlemmer, 



F.R.S 169 



XVII. — On Singular Solutions of Differential Equations. By 

 Robert Rawson, F.R.A.S., Hon. Mem. Manchester 

 Literary and Philosophical Society, Assoc. I.N. A., Memb. 

 of the London Math. Society 170 



XVIII. — On the Formula for the Intensity of Light transmitted 

 through an Absorbing Medium as deduced from Experi- 

 ment. By James Bottomley, B.A., D.Sc, F.C.S 198 



XIX. — On the Intensity of Light that has been transmitted through 

 an Absorbing Medium, in which the Density of the 

 Colouring-matter is a Function of the Distance traversed. 

 By James Bottomley, B.A., D.Sc, F.C.S 20a 



