THE 



Ohio Journal of Science 



PUBLISHED BY THE 



Ohio State University Scientific Society 



Volume XVI JANUARY, 1916 No. 3 



TABLE OF CONTENTS 



Earhart — Notes on the Electrical Behavior of Porcelain and Glass at 



Moderately High Temperatures 81 



Sears — Evaporation and Plant Zones in the Cedar Point Marsh 91 



McCall — A Method for the Renewal of Plant Nutrients in Sand Cultures 101 



Schaffner — Additions to the Catalog of Ohio Vascular Plants lOi 



Melchers — Plant Disease Exhibit Cases 105 



Rice — Ohio Academy of Science. Quarter Centennial Anniversary 109 



NOTES ON THE ELECTRICAL BEHAVIOR OF 



PORCELAIN AND GLASS AT MODERATELY 



HIGH TEMPERATURES. 



RoBT. F. Earhart. 



(Paper read at the Oberlin meeting of the Ohio Academy, Nov., 1913.) 



The experiments described were carried on by the author 

 during the fall and winter of 1912-1913. 



They were suggested by an earlier experiment performed 

 several years ago on the conduction of electricity through 

 gases at high temperatures. During these earlier experiments 

 certain gases were contained in glazed porcelain vessels and 

 subjected to temperatures of 500° and 600° C. It was noted 

 at that time incidentally that when the porcelain was subject 

 to a high e. m. f., a current of some magnitude traversed the 

 porcelain and that while the e. m. f. was steady the current 

 through the porcelain steadily decreased with time. 



Soon after this I suggested an experiment to Mr. Henderson, 

 a student in Ceramics in the Ohio State University, and Mr. 

 Geo. Weimar of the Electrical Engineering Department, which 

 they undertook as a joint thesis. Their experiment consisted 



Si 



