1889.] 



On the Composition of Water. 



425 



Pedler, Professor Alexander, 

 F.C.S. 



Poulton, Edward B., M.A. 



Roberts, Isaac, F.R.A.S. 



Ross, James, M.D. 



Sankey, Matthew Henry P. R., 

 Capt., R.B. 



Saunders, Howard, F.L.S. 



Seebohm, Henry, F.L.S. 



Sharp, David, M.B. 



Shaw, William Napier, M.A. 



Smith, Willoughby. 



Sollas, Professor William John- 

 son, D.Sc. 



Stebbing, Rev. Thomas Roscoe 

 Rede, M.A. 



Stevenson, Thomas, M.D. 



Stewart, J. H. M. Shaw, Major- 

 Gen., R.E. 



Sutton, J. Bland, F.R.C.S. 



Thin, George, M.D. 



Thompson, Professor Silvanns 

 Phillips, D.Sc. 



Thomson, Professor John Millar, 

 F.R.S.E. 



Tidy, Professor Charles Meymott, 

 M.B. 



Todd, Charles, M.A. 



Tomlinson, Herbert, B.A. 



Weldon, Walter Frank Raphael, 

 M.A. 



Whitehead, Charles, F.L.S. 



Yeo, Professor Gerald F., M.D. 



The following Papers were read : 



I. " On the Composition of Water." By LORD RAYLEIGH, 

 Sec. R.S. Received February 26, 1889. 



During the past year I have continued the work described in a 

 former communication on the relative densities of hydrogen and 

 oxygen,* in the hope of being able to prepare lighter hydrogen than 

 was then found possible. To this end various modifications have been 

 made in the generating apparatus. Hydrogen has been prepared 

 from potash in place of acid. In one set of experiments the gas was 

 liberated by aluminium. In this case the generator consisted of a 

 large closed tube sealed to the remainder of the apparatus; and the 

 aluminium was attached to an iron armature so arranged that by 

 means of an external electro-magnet it was possible to lower it into 

 the potash, or to remove it therefrom. The liberated gas passed 

 through tubes containing liquid potash, f corrosive sublimate, finely 

 powdered solid potash, and, lastly, a long length of phosphoric anhy- 

 dride. But the result was disappointing ; for the hydrogen proved 

 to be no lighter than that formerly obtained from sulphuric acid. 



I have also tried to purify hydrogen yet further by absorption in 

 palladium. In his recent important memoir,^ " On the Combustion of 

 weighed Quantities of Hydrogen and the Atomic Weight of Oxygen," 



* 'Koy. Soc. Proc.,' February, 1888 (vol. 43, p. 356). 



f Of course this tube was superfluous in the present case, but it was more conve- 

 nient to retain it. 



' Ajner. Chem. Journ.,' vol. 10, No. 4. 



2 F 2 



