Absorption of ft Rays from Radium by Solutions. 605 



systems of stars, of which upwards of ten thousand have been 

 discovered and catalogued during the last century. 



30. The probability that the ultimate transformation of 

 the solar system will be brought about by the means, and in 

 the order herein set forth, derives further support from the 

 fact that one of the stars of long recognised binary systems 

 is itself a close double star, revolving about its common centre 

 of gravity, as instanced in jm Herculis and 7 Andromedse. 



31. Recapitulation. — (1) That the exact binary progression 

 of the planetary distances is the primordial and fundamental 

 law (shining forth alone in the formless void) from which 

 the principal elements of the planetary orbits have been 

 derived ; (2) that the apparently irregular differences from 

 the law are the direct consequence of the mutual attractions 

 of the planetary bodies amongst themselves, but without 

 affecting the validity of Kepler's laws, as the distances and 

 periodic times are necessarily correlated; (3) that as planetary 

 systems have been evolved in regular order from a nebular 

 substance, >o the transformation of these systems will proceed 

 in like order to form the numerous binary and other revolving- 

 systems observed in the immensity of the stellar universe. 



LXIV. Absorption of ft Rays from Radium by Solutions and 

 Liquids. By W. A. Borodowsky, M.A., Privat-docent of 

 Chemistry, Tour jew (JDorpat) University, Russia*. 



Introduction. 



A LARGE amount of work has been done by various 

 observers in determining the absorption of ft rays from 

 radioactive matter by metals and solids, but little attention 

 has been given to the allied problem of absorption of the rays 

 by solutions and liquids. 



N. Campbell t examined the absorption of the ft rays from 

 uranium by liquids and solutions, but his method of obtaining 

 uniform layers of liquid by means of filter paper is open to 

 objection. The results obtained by him were somewhat 

 irregular, but he concluded that u it is possible that the value 



of - (where \ is the coefficient of absorption and p the 



density of the solution) for a solution should be greater than 

 either of the values for the solvent or the solute, or should 

 be less than either of these values." 



While the present work was in progress a paper was 



* Communicated by Professor E. Rutherford, 1\K.S. 

 t Phil. Mag. 1909, vol. xvii. p. 180. 



