/I/ After oral administration. Mostly absorbed =>705t; partly absorbed = 

 5-70^; mostly unabsorbed =>5^. Extent of absorption may depend on the 

 amount offered; it is assumed that the various ions are offered in the 

 form of simple soluble compounds, or metallic oxides. /2/ Due to in- 

 ade^iuate absorption after oral administration, data on retention and 

 excretion of poorly absorbed elements are frcjm parenteral administra- 

 tion, /j/ Kidney, liver, pancreas, spleen, etc. /k/ Other than in the 

 bile, or by route not definitely established. /5/ Not commonly thought 

 of as normal tissue cationogen, but is present in trace quantities as 

 a result of occurrence in small amounts in animal foods. /6/ Data ob- 

 tained in part from studies using radioactive isotopes. /7/Valence of 

 two. /8/ Probably, in view of position in the periodic table, £ind/or, 

 water solubility. 



147 



