330 



Mr. C. F. Hogley on Solubility oj the 



value, the calculated heating effect is reduced 5 per cent., 

 and the agreement between calculation and experiment is 

 not so good. In order to settle this point, experiments are 

 now in progress to redetermine the values of u and e\m of 

 the a particle from radium C. 



From the data already given, the distribution of the 

 heating effect between radium and its products and radiations 

 is given below. 





Heating effect in gram caiories per hour 

 corresponding to one gram of radium. 



a rays. 



/3 rays. 



y rays. 



Total. 



Radium* 



25-1 

 28-6 

 30-5 



39-4 



4-7 



6-4 



25-1 

 28-6 

 30-5 



50-5 



Emanation 



Radium A 



Radium B | 

 Radium J 



Totals 



123-6 



4-7 



6-4 



134-7 



It follows that the total heating effect of one gram of 

 radium for complete absorption of the a, ft, and <y rays 

 should be about 135 gram calories per hour per gram on the 

 Vienna standard. 



University of Manchester, 1912. 



XXXV. Solubility of the Active Deposit of Thorium in 

 Various Solvents. By C. F. HoGLEY, B.Sc, AM.C.SA 



IN this paper is described an attempt to classify the trans- 

 formation products of thorium in the periodic system by 

 means of their solubilities in various solvents. 



Some thorium hydroxide was placed in a metal dish over 

 which was suspended a small piece of platinum foil which 

 could be easily detached. The active deposit from the 

 thorium was collected in the usual way by connecting the 

 platinum plate to the negative pole of a battery. After two 

 or three days' exposure the plate was removed and its activity 



* During- the publication of this paper, V. F. Hess ( Wien. Ber. cxxi. 

 p. 1, 1912) has published the results of a direct determination of the 

 heating effect of radium freed from all its products. The value obtained, 

 25*2 calories per hour per gram, is in excellent accord with the value 

 calculated from the measurements on the emanation given above. 



t Communicated by the Hon. R. J. Strutt, F.R.S. 



