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WEEKLY EVENING MEETING, \lJ\ ^^•-'►^ ^^ 



Friday, January 17, 1896. ^'•^"^^^f* 



Sir Frederick Abel, Bart. K.C.B. D.C.L. LL.D. F.R.s! 

 Vice-President, in the Chair. 



The Right Hon. Lord Rayi.eigh, M.A. D.C.L. LL.D. F.R.S. 

 31B.L Professor of Natural Philosophy R.I. 



3Iore about Argon. 

 (Abstract.) 



In our original paper* are described determinations by Professor 

 Ramsay, of the density of argon prepared with the aid of magnesium. 

 The volume actually weighed was 163 c.c. and the adopted mean 

 result was 19 '941, referred to O., = 16. At that time a satisfactory 

 conclusion as to the density of argon prepared by the oxygen method 

 of Cavendish had not been reached, although a preliminary result 

 (19*7) obtained from a mixture of argon and oxygen "j" went far to 

 show that the densities of the gases prepared by the two methods 

 were the same. In order further to test the identity of the gases, it 

 was thought desirable to pursue the question of density ; and I deter- 

 mined, as the event proved, somewhat rashly, to attempt large scale 

 weighings of pure argon with the globe of 1800 c.c. capacity 

 employed in former weighings of gases J which could be obtained in 

 quantity. 



The accumulation of the 3 litres of argon, required for convenient 

 working, involved the absorption of some 300 litres of nitrogen, or 

 about 800 litres of the mixture with oxygen. This was effected at 

 the Royal Institution with the apparatus already described, § and 

 which is capable of absorbing the mixture at the rate of about 

 7 litres per hour. The operations extended themselves over nearly 

 three weeks, after which the residual gases amounting to about 

 10 litres, still containing oxygen with a considerable quantity of 

 nitrogen, were removed to the country and transferred to a special 

 apparatus where it could be prepared for weighing. 



For this purpose the purifying vessel had to be arranged some- 

 what differently from that employed in the preliminary absorption 



* Rayleigh and Ramsay, Phil. Trans, vol. 186 A, pp. 221, 238, 1895. 

 t Loc. cit. p. 221. 



X Roy. Soc. Proc. February 1888 ; February 1892 ; March 1893. 

 § Phil. Trans, loc. cit. p. 219. 



Vol. XV. (No. 90.) b 



