.=_-ƒ(?.) 



326 



TABLE 5. 

 Fe2 Ni (saturated) 



Weiss 



TABLE 6. 



8 = (f {t) A = 567 lin Fca Ni (saturated) Weiss 



Calcium ferrite. (CaO . Fe.O^, Hilpert, <^„ = 156°). The rather 

 hard brittle material could be nicel}' polished. The failure of Loria 

 to obtain an effect with this same substance was probably due to 

 an accidental selection of those points in the spectrum at which the 

 rotation is either zero or very small. It is exceetJingly minute, to 

 be sure, throughout. Nevertheless, I was able to determine a curve. 

 Tliis is of the general type with an algebraic minimum in the blue. 



