CONTENTS. 

 VOL. XX. 



No. 130.— November 16, 1871. 



Page 



Considerations on the Abrupt Change at Boiling or Condensing in refer- 

 ence to the Continuity of the Fluid State of Matter. By Professor James 

 Thomson, LL.D 1 



Contributions to the History of the Opium Alkaloids. — Part III. By 

 C. R. A. Wright, D.Sc, Lecturer on Chemistry in St. Mary's Hospital 

 Medical School , 8 



On a Periodic Change of the Elements of the Force of Terrestrial Mag- 

 netism discovered by Professor Hornstein 21 



Corrections to the Computed Lengths of Waves of Light published in the 

 Philosophical Transactions of the year 1868. By George Biddell Airy, 

 C.B., Astronomer Royal 21 



Corrections and Additions to the Memoir on the Theory of Reciprocal 

 Surfaces, Phil. Trans, vol. clix. (1869). By Prof. Cayley, F.R.S 22 



November 23, 1871. 



Second Paper on the Numerical Values of e, log e 2, log e 3, log e 5, and 

 log 6 10 also on the Numerical Value of M, the Modulus of the Common 



System of Logarithms, all to 205 decimals. By William Shanks, 

 Houghton-le-Spring, Durham 27 



Second Paper on the Numerical Value of Euler's Constant, and on the 

 Summation of the Harmonic Series employed in obtaining such Value. 

 By William Shanks, Houghton-le-Spring, Durham 29 



An Experimental Determination of the Velocity of Sound. By E. J. Stone, 

 M.A., F.R.S., Astronomer Royal at the Cape of Good Hope 34 



