Errata 
1 
{À 
na- 
natatoire chez les 
ÿ 
| Dans le titre du travail de Mme C. Reis au lieu de 
OPEL 
x 
tatoire chez les Siluroides nebulosus“ lizes 
Siluroides (Amiurus nebulosus)*. 
mi 
BULLETIN INTERNATIONAL 
IE DES SCIENCES DE CRACOVIE: 
: SCIENCES MATHÉMATIQUES ET NATURELLES. 
«ODLEWSKI. L’actinium et ses produits. 
- ce du lundi 3 Avril 1905. 
Pr&ösınence DE M. N. CYBULSKI. 
{. Aktyn i jego produkty. (Actinium and its suc- 
1). (L’actinium et ses produits). Mémoire présenté par 
nt: 
Soddy ‘) in their well known investigations on 
‘um have shown that it is possible to separate 
re constituent which they call ThX. The acti- 
decays with the time according to an expo- 
equation of monomolecular chemical reactions, 
'e in about four days. At the same time, the 
the removal of thorium X, had been deprived 
3 activity, recovered its activity, the recovery 
nentary to the curve of decay of ThX. The 
-overed earlier by Crookes, acts in a manner 
The activity of this substance decayed accor- 
ıtial law, with the time falling to half value 
Soddy have explained these phenomena on the 
radioactive bodies are producing fresh radio- 
‘onstant rate and that the activity of the mat- 
ases according to an exponential law with the 
y of these phenomena supplied the basis for 
eory which supposes that the atom of a radio- 
up through a series of well marked stages. The 
> oddy: Phil. Mag. Sep. and Nov. 1902. Trans. Chem. Soc. 
