322 Scientific Intelligence. 



Uranium. 



V 

 TIrX. 



I 



V 

 9 



] 



Radium and its family of rapidly-changing products, viz., the 

 emanation, radium A, B, and C. 



1. 



Radium D = primary constituent in radio-lead. 



Radium E. 



I 



Radium F == active constituent in radio-tellurium and polonium. 



No evidence has been obtained that any further active products 

 exist after radium F has been transformed. If the a particle is a 

 helium atom, remembering that five products are present in 

 radium which emit a particles, the atomic weight of the trans- 

 formation product of radium F should be 225 — 20 or 205. This 

 is very close to the atomic weight of lead, 206*7. The view that 

 lead is the final or end product of the transformation of radium 

 is supported by the fact that lead is always found in the radio- 

 active minerals in about the amount to be theoretically expected 

 from the content of uranium, when the quantity of helium, 

 present in the mineral, is used to compute its probable age.* A 

 similar suggestion has recently been advanced by Boltwood." 



II. Geology and Mineralogy. 



1. Indiana, Department of Geology and Natural Resources, 

 Twenty -ninth Annual Report, W. S. Blatchley, State Geologist, 

 1904. 888 pp., 34 pi. — This Twenty -ninth Report of the State 

 Geologist of Indiana is largely devoted to the economic interests 

 of the state, which have shown a very large increase in recent 

 years. Thus comparing the figures for 1895 with those for 1904, 

 although there has been a falling off in natural gas, the amount 

 of coal produced has been more than doubled and that of petro- 

 leum increased nearly three times, while the value of the output 

 of building stone and of clay products has also doubled. Twenty- 

 five years since the resources of the state were almost exclusively 

 agricultural, while in 1904 the total value of the mineral resources 

 amounted to not less than forty million dollars. The present 

 volume discusses very fully the clays and clay industry of the 



* A full discussion of this question was given by the writer in the Silliman 

 Lectures, Yale University, March, 1905. 



