304 
ture the solubility should be minimum and all the emanation escape. 
But the solubility of thorium emanation is not the same in all 
compounds of thorium. A eompound like the hydroxide or carbo- 
nate possesses an equal emanating power in the solid state as in 
solution. This would indicate that thorium emanation so readily 
soluble in thorium nitrate and soluble in thorium oxide is not so 
readily soluble in thorium hydroxide or carbonate. We should 
then expeet that in the last cases the emanating power should 
not be influenced by variation of temperature. The experiments 
of Rutherford and Soddy !) show that this is the case. 
The existence of „deemenated“ products after strong ignition 
whereby many physical and chemical properties of the compound 
are changed, can be also explained by the change in dissolving 
power of these compounds. Further investigations will show if this 
generalisation of the fact observed in the case of uranium is ju- 
stifiable. 
Further experiments on this subject are in progress. Analogous 
experiments will also be tried with other radioactive products in 
order to see if this explanation is general. 
In conclusion I wish to express my best thanks to Prof. Ru- 
therford for the interest he took in this work and for the encou- 
ragement I received from him. 
!) Rutherford and Soddy, Phil. Mag. Apr. 1903 p. 453. 
MeGill University. Physies Building. 
Nakladem Akademii Umiejetnosei. 
Pod redakcya 
Cztonka delegowanego Wydzialu matem.-przyr., Dra Leona Marchlewskiego. 
Kraköw, 1905. — Drukarnia Uniwersytetu Jagiellonskiego, pod zarzadem J. Filipowskiego. 
16 Czerwca 1905. 
