Rubidium Rb 1 



Ruthenium Ru IV 



Scandium 



Selenium or Selenion ' Se VI 



Silicon Si IV 



Silver Ag 1 



Sodium : Na 1 



Strontium Sr 11 



Sulphur (S 11 & S IV ) S VI 



Tantalum Ta v 



Tellurium Te VI 



Terbium? Tb 11 



Thallium Tl nl 



Thorinum or Thorium Th 11 



Tin (Sn 11 ) Sn IV 



Titanium Ti lv 



Tungsten W VI 



Uralium 



Uranium U VI 



Vanadium V v 



\tterbium? Yb 



Yttrium Y n 



Zinc Zn 11 



Zirconium Zi 11 



ACIDULOUS RADICALS. 



Before leaving the subject of elementary chemis- 

 try we will mention the Acidulous Radicals, of 

 which we give a table below, together with their 

 quantivalence. These elements and compounds are 

 termed radicals, each being the common root (radix) 

 in a series of salts. Why compound radicals (as 

 NO 3 , SO 4 , PO 4 , etc.) differ in quantivalence cannot 

 well be explained. Their constituent atoms doubt- 

 less always exert the same amount of attractive 

 force, nearly but not quite all this force being ex- 



-31 



